Phase I study: safety and efficacy of ex vivo-expanded allogeneic natural killer cells (MG4101) with rituximab for relapsed/refractory B-cell non-Hodgkin lymphoma

Phase I study: safety and efficacy of ex vivo-expanded allogeneic natural killer cells (MG4101) with rituximab for relapsed/refractory B-cell non-Hodgkin lymphoma | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Phase I study: safety and efficacy of ex vivo-expanded allogeneic natural killer cells (MG4101) with rituximab for relapsed/refractory B-cell non-Hodgkin lymphoma Won Seog Kim, Dok Hyun Yoon, Youngil Koh, Miyoung Jung, Jeong-Eun Kwak, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-1852342/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract MG4101, an ex vivo -expanded allogeneic natural killer cell, can enhance rituximab antibody-dependent cytotoxicity in relapsed/refractory B-cell non-Hodgkin lymphoma (r/rNHL). Its safety and efficacy were assessed in this phase I trial. Patients received escalating doses of intravenous MG4101 every 2 weeks plus rituximab. Interleukin-2 was administered subcutaneously after MG4101 treatment. Fludarabine plus cyclophosphamide was administered intravenously before rituximab in cycles 1, 3, and 5. A 3 + 3 design was used to determine the maximum tolerated dose (MTD) and maximum feasible dose (MFD). Assessments were performed over a six-cycle period, with an extended maintenance period of up to eight cycles. Nine patients received three different doses of MG4101 and rituximab. MTD could not be determined because of the absence of dose-limiting toxicity. Treatment-related adverse events, mostly grade 1 or 2, occurred in 89% patients. Only one patient experienced grade 1 cytokine release syndrome. MG4101 persisted for at least 7 days in seven patients. Four patients achieved a partial response, and one attained a complete response, yielding a 55.6% response rate. Two patients showed prolonged responses and low exhaustion marker levels in T cells. MG4101 plus rituximab presented a favorable safety profile and overall response rate in patients with r/rNHL. Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction Despite improved treatment outcomes for non-Hodgkin lymphoma (NHL), prognosis remains poor, with an unmet need for novel therapies [ 1 ]. Rituximab is the cornerstone for treating B-cell NHL, and attempts have been made to enhance its clinical benefits by combining with chemotherapy or cell therapy, such as natural killer (NK) cell treatment. Rituximab is used for antibody-dependent cell-mediated cytotoxicity (ADCC) therapy that requires immune cells to induce anti-tumor cytotoxicity activated by antibodies linked to target cells. It triggers innate immune responses and cytotoxicity in tumor cells and induces pro-inflammatory cytokine production to rapidly stimulate adaptive immune responses [ 2 ]. Tisagenlecleucel, a chimeric antigen receptor T cell T-cell (CAR-T) therapy, is remarkably effective and has exhibited durable clinical response in treating B-cell NHL in phase II clinical trials. However, grade 3/4 treatment-related adverse events occurred in 77% of patients, and life-threatening toxicities were also reported [ 3 ]. Furthermore, tisagenlecleucel failed to improve survival in patients with aggressive, relapsed, or refractory NHL [ 4 ]. NK cells are innate lymphoid immune cells that contribute to anti-tumor responses, preventing tumor growth and dissemination. Adoptive transfer of autologous NK cells is safe, albeit ineffective, with an impaired capacity to mediate direct cytotoxic and antibody-mediated killing [ 5 ]. Haploidentical donor NK cells with rituximab is promising against advanced NHL [ 6 ]. Additionally, allogeneic NK cells have been proposed as an effective therapeutic option [ 7 ]. Adoptive allogeneic NK cell therapy in a non-transplant setting is well tolerated and efficacious in lymphoid malignancies, suggesting that it is effective for overcoming an immunosuppressive tumor microenvironment [ 8 ]. MG4101, a novel therapeutic agent, consists of cryopreserved, ex vivo -expanded allogeneic and highly activated NK cells. It was generated from the KIR B/x haplotype in unrelated healthy individuals with a higher affinity for the hFcγRIIIa V158 variant. MG4101 is safe and could influence immune responses through the activation of T-cells and inhibition of suppressive cells and molecules, despite having a relatively short persistence (4 days) [ 9 ]. Combination of MG4101 and rituximab led to higher survival rates than rituximab monotherapy in a murine lymphoma model [ 10 ]. In this phase I study, we evaluated the safety and preliminary efficacy of MG4101 in combination with rituximab in patients with relapsed/refractory B-cell NHL (r/rNHL). Methods Study design and patient eligibility Eligible patients were ≥ 19 years old with confirmed r/rNHL of B-cell origin (mature B-cell lymphoma according to the World Health Organization, Geneva [WHO]). Patients were required to have an Eastern Cooperative Oncology Group performance status of 0 or 1; life expectancy ≥ 3 months; adequate hematologic, hepatic, and renal functions based on appropriate tests; immunophenotyping indicating CD20-positive status, toxicities due to prior treatments that were stable; recovery from toxicities of Common Terminology Criteria for Adverse Events (CTCAE) grade ≤ 1, except for clinically non-significant toxicities, such as alopecia. Informed consent was obtained from all patients. The trial was conducted in accordance with the International Conference on Harmonization Good Clinical Practice guidelines and applicable local regulatory requirements and laws. The clinical protocol was in accordance with Helsinki Declaration of 1975 and approved by the Korean Ministry of Food and Drug Safety (protocol number: MG4101-NHL-P1; October 2, 2018). This dose-escalation study followed a classic 3 + 3 design to evaluate the maximum tolerated dose (MTD) (Fig. 1 ). No patient received an escalated dose until at least three patients had received the previous dose and had been assessed for dose-limiting toxicity (DLT). Doses escalated in cohorts of three patients showed that no MG4101-related DLT occurred in cycle 1. Each cycle lasted 4 weeks and the initial component of phase I consisted of six cycles. Additional treatment for up to eight cycles was allowed as maintenance therapy in the extension component of phase I. Treatment In a previous single-centre phase I dose-escalation study of MG4101 in patients with previously treated malignant lymphoma, or advanced, recurrent solid tumors, a dose of 3 × 10 7 cells/kg administered intravenously was considered the maximum feasible dose (MFD) because of the lack of DLT [ 9 ]. Therefore, here, the three cohorts received MG4101 at the following doses: 1 × 10 7 (level 1), 3 × 10 7 (level 2), and 9 × 10 7 cells/kg (level 3). MG4101 was administered every 2 weeks, beginning at least 1 h after the first dose of rituximab (375 mg/m 2 , intravenously) for the first six cycles (Fig. 2 ). Interval of MG4101 infusion was determined based on persistence of NK cells, pharmacokinetic results of a previous phase I trial, and half-life of rituximab [ 11 ]. Interleukin (IL)-2 was administered subcutaneously at 1 × 10 6 IU/m 2 /day, at least 1 h after MG4101 administration, to enhance NK cell expansion. During the maintenance therapy (cycles 7‒14), MG4101 was administered only on the first day of each cycle, and IL-2 was not administered. Rituximab was administered weekly for the first two cycles and then on the first day of cycles 3‒14. For lymphodepletion, fludarabine (20 mg/m 2 ) plus cyclophosphamide (250 mg/m 2 ) was administered intravenously for three days before rituximab in cycles 1, 3, and 5. Endpoints and assessments The primary endpoint was the MTD of MG4101 in combination with rituximab. In cases where MTD was not reached, MFD was used. MFD was defined as the dose administered to maximize exposure. MTD was defined as the highest dose with which six patients had been treated with less than two occurrences of DLT. DLT was defined as any treatment-related toxicity of CTCAE grade ≥ 3 and graft-versus-host disease (GVHD) of grade ≥ 3. DLTs were assessed during cycle 1, including the first two doses of the investigational agent. The secondary endpoints included the objective response rate (ORR) according to the investigator’s assessment, complete response (CR), and partial response (PR), determined between the start of treatment and up to six cycles. Overall survival, time-to-progression (TTP), and time-to-response were additional secondary endpoints. Responses were evaluated using computed tomography (CT) or positron emission tomography (PET)-CT. Radiological assessments were performed locally, according to the Lugano classification for NHL [ 12 ]. Additional endpoints included assessing adverse events according to CTCAE version 5.0, GVHD assessment, and allogeneic antibody generation. Exploratory evaluations included immunological assays, MG4101 pharmacokinetics, and human leukocyte antigen-killer-cell immunoglobulin-like receptor (HLA-KIR) analysis between donor and subject. Immunostaining and flow cytometry Flow cytometry analysis of changes in immune cell populations and various activation/exhaustion markers after MG4101 administration was performed on serially acquired peripheral blood mononuclear cells (PBMCs). Antibodies used to assess the proportion of memory T cells are listed in Table S2. Stained cells were acquired on LSRFortessa (BD Biosciences, San Jose, CA, USA), and data were analyzed using FlowJo software (FLOWJO, LLC, Ashland, OR, USA). Cytokine measurements Blood samples were collected at specific time points for cytokine analyses and were immediately centrifuged ( 800 × g, 10 min, 4°C), divided into aliquots, and stored at − 80°C for subsequent analysis. Serum (IL-6, IL-8, IL-10, transforming growth factor-β1 (TGF-β1), tumor necrosis factor-α (TNF-α), and C-reactive protein (CRP) levels were measured using a sandwich enzyme-linked immunosorbent assay with Quantikine kits (R&D Systems, Minneapolis, MN, USA). Limit of detection for the cytokines was defined according to the manufacturer’s instructions (IL-1β/12p70/-17, TNF-α, and IFN-γ: 2.0 ng/mL; IL-6/-4/-10: 1.0 ng/mL). Pharmacokinetics Pharmacokinetic analysis of MG4101 was performed by confirming the presence of donor DNA in the patients’ blood through nested polymerase chain reaction (PCR) at various time points. Nested PCR was performed to detect the presence of allo-HLA-DRB1 genes of donor NK cell origin as described previously [ 9 ]. Statistical analyses Statistical analyses were conducted using SAS software (version 9.4; SAS Institute Inc., Cary, NC, USA). Descriptive statistics were determined for demographic and baseline data, including mean, standard deviation, median, and range for continuous variables and frequency and percentage for categorical data. Statistical significance was set at two-sided p < 0.05. ORRs are presented with Clopper–Pearson’s 95% confidence interval (CI) on both sides, and Kaplan–Meier method was used for time-to-event analyses. Paired t -test or Wilcoxon signed-rank test was used for intragroup comparisons in exploratory immunological analyses. Results Patient characteristics and treatment This study was conducted at three tertiary cancer centres in South Korea between April 2019 and October 2020. Baseline characteristics of the nine patients who participated herein are summarized in Fig. 1 and Table 1 . Median age of the patients was 64 (range: 38.0‒80.0) years, most patients were male (78%), and six patients (67%) had received ≥ 4 prior systemic therapy regimens. Three patients (33%) had received prior autologous stem cell transplantation. Table 1 Demographic and baseline characteristics (n = 9) Characteristics Level 1 (n = 3) Level 2 (n = 3) Level 3 (n = 3) Total (n = 9) Median age at baseline, years (range) 64 (38‒80) 61 (56‒69) 66 (57–80) 64 (38‒80) Gender, n (%) Male 2 (66.7) 2 (66.7) 3 (100) 7 (77.8) Female 1 (33.3) 1 (33.3) - 2 (22.2) Baseline ECOG PS, n (%) 0 2 (66.7) - 2 (66.7) 4 (44.4) 1 1 (33.3) 3 (100) 1 (33.3) 5 (55.6) Pathologic subtypes, n (%) Diffuse large B-cell lymphoma 2 (66.7) 3 (100) 1 (33.3) 6 (66.7) Follicular lymphoma - - - - Mantle cell lymphoma 1 (33.3) - 1 (33.3) 2 (22.2) Marginal zone lymphoma - - 1 (33.3) 1 (11.1) No. of prior systemic therapy regimens, n (%) 2 1 (33.3) 1 (33.3) - 2 (22.2) 3 1 (33.3) - - 1 (11.1) ≥ 4 1 (33.3) 2 (66.7) 3 (100) 6 (66.7) International Prognostic Index (IPI), n (%) Low Risk - - 1 (33.3) 1 (11.1) Low-Intermediate Risk 2 (66.7) 1 (33.3) - 3 (33.3) High-Intermediate Risk - 1 (33.3) 1 (33.3) 2 (22.2) High Risk 1 (33.3) 1 (33.3) 1 (33.3) 3 (33.3) Other prior anti-cancer treatment, n (%) Prior radiation therapy 2 (66.7) 1 (33.3) 1 (33.3) 4 (44.4) Prior hematopoietic stem cell transplantation 1 (33.3) 1 (33.3) 1 (33.3) 3 (33.3) Abbreviations: ECOG PS, Eastern Cooperative Oncology Group performance status Patient disposition and regimen design are shown in Figs. 1 and 2 , respectively. Three patients were assigned to each MG4101 dose level, and all nine patients completed at least one cycle. Eight patients (88.9%) discontinued the study before completing cycle 6. One patient received maintenance therapy after cycle 6, but treatment was discontinued after cycle 7. All patients were evaluated for efficacy, safety, and exploratory endpoints. Safety and tolerability Treatment was well-tolerated, and most treatment-emergent adverse events (TEAEs) were grade 1 or 2 (68.9%). Drug-related TEAEs occurred in 89% of the patients; most common were grade 1–2 neutropenia and pyrexia. One patient experienced grade 1 cytokine release syndrome (CRS), and neurotoxicity was not observed. The most common adverse events were neutropenia, thrombocytopenia, pyrexia, and nausea (Table 2 ). The most common grade ≥ 3 TEAE was neutropenia ( n = 6); three patients experienced febrile neutropenia. One level 1 patient experienced Pneumocystis jirovecii pneumonia, which led to treatment discontinuation. However, GVHD, treatment-related mortality, and DLTs were not observed. As there was no treatment-emergent DLT in the nine participants at any dose, the MFD was set at the highest dose (9 × 10 7 cells/kg). Table 2 Treatment-emergent adverse events (TEAEs) reported in ≥ 2 cases. TEAE, n (%) Level 1 (n = 3) Level 2 (n = 3) Level 3 (n = 3) Total (n = 9) Grade 1–2 Grade 3–4 Grade 1–2 Grade 3–4 Grade 1–2 Grade 3–4 Grade 1–2 Grade 3–4 Hematologic AE Anaemia 1 1 - - - - 1 (11.1) 1 (11.1) Neutrophil count decrease - 3 1 1 1 1 2 (22.2) 5 (55.6) Platelet count decrease 1 1 - - - - 1 (11.1) 1 (11.1) Febrile neutropenia - 1 - 2 2 - 2 (22.2) 3 (33.3) Non-hematologic AE Pyrexia 3 - 1 - 1 - 5 (55.6) - Cytokine Release Syndrome 1 - - - - - 1 (11.1) - Hypotension - 1 1 - - - 1 (11.1) 1 (11.1) Cough 1 - - - - - 1 (11.1) - Nausea 2 1 1 - 1 - 4 (44.4) 1 (11.1) Dyspnoea - 1 1 - - - 1 (11.1) 1 (11.1) Decreased appetite - - 3 2 - - 3 (33.3) 2 (22.2) Fatigue - - 2 - - - 2 (22.2) - Hypersensitivity - 1 1 - - - 1 (11.1) 1 (11.1) Gastrointestinal disorder - - 1 - 1 - 2 (22.2) - Vomiting - - 1 - 1 - 2 (22.2) - Efficacy ORR was 55.6%; four patients achieved PR (3 DLBCL, 1 MCL), one achieved CR (1 MZL), and four showed PD (3 DLBCL, 1 MCL) (Fig. 3 A and Table S1). Responses were observed across all three doses: 2 PR at level 1, 1 PR at level 2, 1 PR and 1 CR at level 3. Median time for response ( n = 5) was 60.0 days (95% CI: 22.0–100.0) and median duration of response ( n = 5) was 45.0 (range: 22.0‒806.0) days (Fig. 3 B). Notably, a continued response over 806 days was observed in patient 8203106, who achieved CR at level 3 (cut-off date: 2022-03-31) (Figs. 3 A and 3 C). Eight patients experienced PD, and median TTP was 50.0 days (95% CI: 22.0–355.0). Overall median survival time in level 2 was 72.0 days (95% CI: 69.0–75.0). Generation of allogeneic antibodies and pharmacokinetics In the antibody HLA Class I and II measurements between donors and subjects, the donor-specific antibody, HLA Cw15, was detected in one patient (Level 3: 8203106). MG4101 persisted for up to 7 days in seven patients and 14 days in two patients (Table S3). Immunological assessments We examined changes in immune cell frequencies at baseline, during cycle 1, and at the end of treatment (EOT). The proportion of CD19 + B-cells was low (< 1%) throughout the treatment. The percentage of CD3 − CD56 + NK cells and regulatory T-cells (CD4 + Foxp3 + CD127 low ) did not change during the treatment (Fig. 4 A). The proportion of CD3 + T-cells significantly increased after treatment (26.53 ± 28.88%, p = 0.0249), mainly due to an increase in the CD8 + T-cell population (46.62 ± 228.6%, p = 0.0003), resulting in a lower ratio of CD4 + T cells/CD8 + T-cells than the baseline (2.38 ± 0.89 vs. 0.53 ± 0.61, p = 0.0007) (Fig. 4 A). While the percentage of naïve and central memory cells (Tcm) was reduced (Naïve: 9.69% ± 10.99% → 3.56% ± 6.53%, p = 0.0315; Tcm: 43.36% ± 21.90% → 19.63% ± 19.92%, p = 0.0244), that of the effector memory subtypes (Tem, Temra) was increased (Tem: 45.81% ± 19.54% → 72.63% ± 20.39%, p = 0.0078; Temra: 1.16% ± 2.04% → 4.18% ± 4.71%, p = 0.0034) among CD4 + T cells. Similar results were observed for CD8 + T cells, in which effector memory cells were the predominant subset after treatment (Fig. 4 B). We analyzed the expression profiles of key activation (HLA-DR + CD38 + , NKG2D, 41BB, and CTLA-4) and exhaustion (PD-1, TIGIT, TIM-3, and LAG-3) molecules in T cells. Treatment significantly increased their levels. HLA-DR + CD38 + , NKG2D, and 41BB were activated at early time points, which diminished over time; TIM-3 and TIGIT expression increased and was maintained until EOT (Fig. 4 C). Exceptionally, CTLA-4 expression was decreased in CD8 + T cells, whereas LAG-3 expression was unaffected. Cytokine levels were analyzed at each visit among the dose groups (Figure S1); no evidence of cytokine storm (or CRS) throughout the treatment was noted. Further exploratory immunological assessment focused on five exhaustion markers (CTLA-4, LAG-3, PD-1, TIGIT, and TIM-3) between long-term responders whose response lasted over 12 months (8203101 in level 1 and 8203106 in level 3) and others at various time points. Interestingly, short-term responders or non-responders had a greater frequency and showed multiple expressions of these markers than long-term responders (Fig. 5 A). Notably, LAG-3 and TIM-3 expression was low from the start to the EOT (LAG-3 + /CD4 + : 0.36% vs. 5.039%, p = 0.046; LAG-3 + /CD8 + : 0.56% vs. 3.914%, p = 0.232; TIM-3 + /CD4 + : 6.39% vs. 17.87%, p = 0.094; TIM-3 + /CD8 + : 13.6% vs. 22.53%, p = 0.290), rendering the immune environment favorable for long-term responders (Fig. 5 B). Furthermore, the CD4 + /CD8 + T-cell ratio, an indicator of cellular immune function, was notably high in long-term responders (1.102 vs. 0.259, p = 0.000029); inversely, the ratio decreased rapidly in others, from 2.461 to 0.259 (Fig. 5 C). Analysis of the donors and subjects for HLA-KIR Four (44.4%) patients had one KIR mismatch, and five (55.6%) had two KIR mismatches (Table S4). However, there was no significant difference in the number of mismatched KIRs or activating KIRs between responders and non-responders (mismatched KIR, p = 1; activating KIRs, p = 0.5238). Discussion This phase I trial demonstrated that the combination of MG4101 and rituximab was well tolerated in patients with heavily pre-treated r/rNHL, with an encouraging response rate (55.6%). The best response was stable disease in a previous phase I study of MG4101 in patients with r/rNHLs or solid metastatic tumors, although the MFD was lower than that herein [ 9 ]. Compared with the previous trial, this study combined rituximab and the high-affinity CD16 158V variant of NK cells with haplotype B after lymphodepleting chemotherapy with fludarabine and cyclophosphamide. Patients expressing the high-affinity hFcγRIIIa V158 variant reportedly showed good clinical outcomes with rituximab or trastuzumab than those homozygous for the lower-affinity hFcγRIIIa F158 variant [ 13 ]. Moreover, a preparative regimen of fludarabine plus cyclophosphamide is known to deplete host cells and prolong the persistence of administered cells. Furthermore, rituximab combined with MG4101 acted synergistically with ADCC. Therefore, these factors may have contributed to the higher response rates observed herein. Combination therapy is associated with the reversal of the tumor microenvironment, which provides a favorable microenvironment that better supports anti-tumor immunity. The tumor microenvironment plays an essential role in the disease course and clinical outcomes after NHL [ 14 ]. MG4101 plus rituximab regulates both innate and adaptive immunity by increasing the proportion of T-cell subsets with effector memory and upregulating activation and exhaustion markers on T cells, leading to immune response activation. Particularly, HLA-DR + CD38 + and NKG2D upregulation in CD8 + T-cells may be associated with memory cell differentiation. In line with the increase in the proportion of effector memory T cells, these results suggest that MG4101 plus rituximab induces early T-cell activation and shifts the immune response to late activation/exhaustion and differentiation status. Evidence indicates that NK cells contribute to adaptive immunity through crosstalk with other immune cells, including T cells, B cells, and dendritic cells (DCs). NK cells promote Th1 polarization through IFN-γ production and indirectly enhance adaptive T-cell response by promoting DC maturation [ 15 ]. These therapeutic responses to MG4101 plus rituximab combination were associated with peripheral blood circulating activated T-cells and mature DCs. Exploratory analysis of long-term versus short-term responders have focused on the expression of T-cell exhaustion markers [ 16 , 17 ]. Long-term responders tended to have lower expression of exhaustion markers than short-term responders when expressions before and after treatment were compared. Thus, a less-exhausted immune environment and functional cellular response may contribute to better responses in long-term responders to MG4101 plus rituximab. Although this trial involved a relatively small cohort, low expression of exhaustion markers, particularly LAG-3 and TIM-3, was likely related to the therapeutic effect. Low expression of exhaustion markers in patient PBMCs implies that it can prevent the ‘off’ signal from being sent, allowing the T-cells to kill tumor cells, turning immunologically ‘cold tumors’ to ‘hot tumors’. Furthermore, a high CD4 + :CD8 + ratio was observed in long-term responders compared with that in other patients [ 18 ]. Low expression of exhaustion markers, together with a high CD4 + :CD8 + ratio, could be a favorable predictive biomarker of a good response in patients with r/rNHL. However, further investigations with a larger cohort are needed to draw firm conclusions. Production of donor-specific HLA antibodies (DSA) might affect the persistence of NK cells, leading to a decreased response. DSA was detected in patients with solid tumors after NK infusion without a preparative regimen [ 9 ]. However, most patients did not develop DSA, which might be related to lymphodepleting chemotherapy. Additionally, MG4101 was detected for up to 2 weeks, compared with 3 or 4 days in a previous study that did not incorporate any lymphodepleting treatment [ 9 ]. The safety and efficacy of NK cell therapy have been demonstrated in both autologous and allogeneic haploidentical settings [ 19 ]. Autologous NK cells combined with rituximab have shown promising results, with over 70% of patients maintaining CR [ 20 ]. However, it is difficult to prove the exact contribution of NK cells to the CR because most patients received chemotherapy after autologous NK cell treatment. Interestingly, herein, one patient (8203106) switched from PR to CR despite no additional treatment after trial completion. This provides evidence favoring the adoptive transfer of unrelated allogeneic NK cells concomitantly with rituximab for a better immune response, with manageable safety profile and preliminary efficacy in patients with r/rNHL. Safety is the major advantage of NK cell therapies. Clinical studies have shown promising tumor regression responses without severe adverse events [ 21 , 22 ]. Additionally, allogeneic NK cell treatment is known to exert a strong graft-versus-tumor effect without GVHD development [ 23 – 29 ]. Induction of remission in more than 25% of patients with highly refractory NHL by haploidentical NK cells [ 10 ] spurred the development of donor NK cell therapy for advanced NHL. Given the previous successful leukemia treatment with alloreactive haploidentical KIR ligand-mismatched NK cells [ 26 ], it was expected that MG4101 would be safe and enhance clinical benefit in patients with r/rNHL. CD19-directed CAR-T-cells are currently approved for r/rNHL. Nevertheless, severe CRS or neurotoxicities were noted in a considerable proportion of patients [ 30 ]. MG4101 prepared from healthy non-HLA-matched individuals was well tolerated with no signs of cytokine storm, neurotoxicity, or GVHD, unlike CAR-T-cell therapy. Only one patient experienced grade 1 CRS, which was self-limiting, and none developed neurotoxicities. Immunological assays also showed no evidence of elevated cytokine levels, consistent with other findings suggesting an absence of a cytokine storm or CRS with NK cell treatment [ 31 ]. For allogeneic NK cell therapy, strategies including the use of the higher affinity hFcγRIIIa V158 variant of KIR B/x haplotype with lymphodepleting chemotherapy could be promising options for improving clinical efficacy in the antibody combination therapeutic setting as an off-the-shelf product. This clinical study demonstrated that combination treatment with MG4101 and rituximab is feasible, yielding a favorable safety profile and encouraging response rates in patients with r/rNHL. Declarations Acknowledgments: Under the authors’ guidance, medical writing support was provided by Greg Plosker and David Figgitt, Ph.D., ISMPP CMPP™, and Content Ed Net. We thank the investigators, site support staff, and the patients who participated in this study. This work was supported by the GC Cell Corp., South Korea. Author Contributions: Conception and design: Dok Hyun Yoon Development of methodology: Dok Hyun Yoon, Youngil Koh, Won Seog Kim, Eui-Cheol Shin Acquisition of data: Dok Hyun Yoon, Youngil Koh, Won Seog Kim Analysis and interpretation of data: Dok Hyun Yoon, Youngil Koh, Miyoung Jung Writing, review, and revision of the manuscript: Dok Hyun Yoon, Youngil Koh, and Yu Kyeong Hwang Administrative, technical, or material support: Miyoung Jung, Jeong-Eun Kwak Study supervision: Won Seog Kim Other (study conduction): Dok Hyun Yoon, Youngil Koh, Won Seog Kim Conflicts of interest: The authors have no competing interests. Data sharing statement: The data generated during the study are available from the corresponding author on reasonable request. References Rovira J, Valera A, Colomo L, Setoain X, Rodríguez S, Martínez-Trillos A, et al . 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NK cell-based cancer immunotherapy: From basic biology to clinical development. J Hematol Oncol. 2021; 14: 7. Tanaka J, Tanaka N, Wang YH, Mitsuhashi K, Ryuzaki M, Iizuka Y, et al . Phase I study of cellular therapy using ex vivo expanded natural killer cells from autologous peripheral blood mononuclear cells combined with rituximab-containing chemotherapy for relapsed CD20-positive malignant lymphoma patients. Haematologica. 2020; 105: e190–e193. Zhang Y, Schmidt-Wolf IGH. Ten‐year update of the international registry on cytokine‐induced killer cells in cancer immunotherapy. J Cell Physiol. 2020; 235: 9291–9303. Zhang Y, Xia L, Zhang Y, Wang Y, Lu X, Shi F, et al . Analysis of adverse events following the treatment of autologous cytokine-induced killer cells for adoptive immunotherapy in malignant tumor sufferers. Expert Opin Biol Ther. 2015; 15: 481–493. He Y, Tian Z. NK cell education via nonclassical MHC and non-MHC ligands. Cell Mol Immunol. 2017; 14: 321–330. Shin MH, Kim J, Lim SA, Kim J, Kim SJ, Lee KM. NK cell-based immunotherapies in cancer. Immune Network. 2020; 20: e14. Park H, Rho EY, In JW, Kim I, Yoon SS, Park S, et al . The impact of HLA and KIR ligand mismatching on unrelated allogeneic hematopoietic stem cell transplantation in Korean adult patients. Ann Lab Med. 2015; 35: 111–117. Heidenreich S, Kröger N. Reduction of relapse after unrelated donor stem cell transplantation by KIR-based graft selection. Front Immunol. 2017; 8: 41. Nguyen R, Wu H, Pounds S, Inaba H, Ribeiro RC, Cullins D, et al . A phase II clinical trial of adoptive transfer of haploidentical natural killer cells for consolidation therapy of pediatric acute myeloid leukemia. J Immunother Cancer. 2019; 7: 81. Ruggeri L, Parisi S, Urbani E, Curti A. Alloreactive natural killer cells for the treatment of acute myeloid leukemia: From stem cell transplantation to adoptive immunotherapy. Front Immunol. 2015; 6: 479. Leung W. Infusions of allogeneic natural killer cells as cancer therapy. Clin Cancer Res. 2014; 20: 3390–3400. Dores GM, Jason C, Niu MT, Perez-Vilar S. Adverse events reported to the U.S. Food and Drug Administration adverse event reporting system for tisagenlecleucel. Am J Hematol. 2021; 96: 1087–1100. Karadimitris A. Cord blood CAR-NK cells: favorable initial efficacy and toxicity but durability of clinical responses not yet clear. Cancer Cell. 2020; 37: 426–427. Additional Declarations The authors have declared there is NO conflict of interest to disclose. Supplementary Files Supplementaryfiles.pdf Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-1852342","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":122314792,"identity":"86150f43-8328-4218-9a22-d4bcf92f477b","order_by":0,"name":"Won Seog Kim","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAvklEQVRIiWNgGAWjYFACNoYDIIqfgY0ZRDM2EK1FsoEULWBgcIBYLQbnjyUeuvFnm7zx+WPJxjwMNrIbDhDSciPtwOHcttuG226kHU7mYUgzJqjF7AZ7w+HchtsJQEbzYR6Gw4mEtZw/3nA458/tBOP+4yAt/4nQcgDosBy22wkGDGCHHSCsxf5GWgLYLzNupCUbzjFINp5JSItk/zHjz0CHyfMDGRJvKuxk+whpQQMGpCkfBaNgFIyCUYADAAAe/0oPcNEaaAAAAABJRU5ErkJggg==","orcid":"https://orcid.org/0000-0002-5400-0466","institution":"Samsung Medical Center, Sungkyunkwan University School of Medicine","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Won","middleName":"Seog","lastName":"Kim","suffix":""},{"id":122314793,"identity":"c418afa0-4d10-46fc-9a29-2f55b3f54f0d","order_by":1,"name":"Dok Hyun Yoon","email":"","orcid":"","institution":"Asan Medical Center, University of Ulsan College of Medicine","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Dok","middleName":"Hyun","lastName":"Yoon","suffix":""},{"id":122314794,"identity":"613a0e64-5019-4a16-b98d-0110d465a092","order_by":2,"name":"Youngil Koh","email":"","orcid":"","institution":"Seoul National University Hospital","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Youngil","middleName":"","lastName":"Koh","suffix":""},{"id":122314795,"identity":"2bbdef81-97f7-40a4-aba9-1dbf1a8f3761","order_by":3,"name":"Miyoung Jung","email":"","orcid":"","institution":"GC Cell","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Miyoung","middleName":"","lastName":"Jung","suffix":""},{"id":122314796,"identity":"b5f2f1da-45af-4271-ac18-135a63e2a055","order_by":4,"name":"Jeong-Eun Kwak","email":"","orcid":"","institution":"GC Cell","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Jeong-Eun","middleName":"","lastName":"Kwak","suffix":""},{"id":122314797,"identity":"220b173f-de6b-4fe7-a697-a5a83ed8a44b","order_by":5,"name":"Eui-Cheol Shin","email":"","orcid":"","institution":"Korea Advanced Institute of Science and Technology (KAIST)","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Eui-Cheol","middleName":"","lastName":"Shin","suffix":""},{"id":122314798,"identity":"6966c035-8bed-4c8c-b573-d3a07c75cf16","order_by":6,"name":"Yu K. Hwang","email":"","orcid":"","institution":"GC Cell","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Yu","middleName":"K.","lastName":"Hwang","suffix":""}],"badges":[],"createdAt":"2022-07-13 02:10:42","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-1852342/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-1852342/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":24157799,"identity":"0564f5d5-cfdc-4f1b-8fa5-cb7b178a725e","added_by":"auto","created_at":"2022-07-21 17:32:15","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":21023,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eStudy design\u003c/strong\u003e.\u003c/p\u003e\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"Figure1.png","url":"https://assets-eu.researchsquare.com/files/rs-1852342/v1/4d8b820530b0287e668f6c96.png"},{"id":24158877,"identity":"4ed33560-3c37-4641-bb9f-5e59f42eda12","added_by":"auto","created_at":"2022-07-21 17:42:15","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":43043,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eTreatment schema\u003c/strong\u003e. Patients were administered lymphodepleting chemotherapy consisting of fludarabine (20 mg/m\u003csup\u003e2\u003c/sup\u003e) and cyclophosphamide (250 mg/m\u003csup\u003e2\u003c/sup\u003e) on days -3 to -1 before the first administration of rituximab, and MG4101 of cycles 1, 3, and 5. MG4101 and IL-2 (1 × 10\u003csup\u003e6 \u003c/sup\u003eIU/m\u003csup\u003e2\u003c/sup\u003e) were subcutaneously administered every 2 weeks for six cycles. Each of the six cycles was started sequentially every 28 days. Patients also received rituximab (375 mg/m\u003csup\u003e2\u003c/sup\u003e) every 2 weeks during the first two cycles and then once every 28 days until cycle 6. After six cycles, additional one or two cycles of treatment were allowed.\u003c/p\u003e\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"Figure2.png","url":"https://assets-eu.researchsquare.com/files/rs-1852342/v1/72cbbe481ffb05385c70d8ad.png"},{"id":24158425,"identity":"69acd347-467d-4031-b8f2-2da440917b77","added_by":"auto","created_at":"2022-07-21 17:37:15","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":204031,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eEfficacy of MG4101 plus rituximab\u003c/strong\u003e. (\u003cstrong\u003eA\u003c/strong\u003e) Swimmer plot of objective response and disease progression (\u003cem\u003en\u003c/em\u003e = 9). (\u003cstrong\u003eB\u003c/strong\u003e) Waterfall plot of maximum percent change in SPD from baseline. (\u003cstrong\u003eC\u003c/strong\u003e) A patient with relapsed MZL with a large mesenteric mass and retroperitoneal lymph node involvement achieved a CR after six treatment cycles. Abbreviations: CR, complete response; DLBCL, diffuse large B-cell lymphoma; MCL, mantle cell lymphoma; MZL, marginal zone lymphoma; PET-CT, positron emission tomography-computed tomography; PR, partial response; SPD, sum of the product of the diameters.\u003c/p\u003e\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"Figure3.png","url":"https://assets-eu.researchsquare.com/files/rs-1852342/v1/9e2ff4594980a08d422733f7.png"},{"id":24157800,"identity":"8d3d223d-d172-40c8-b41f-09f13ca138eb","added_by":"auto","created_at":"2022-07-21 17:32:15","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":111599,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eAnalysis of immune cell proportion and activation/exhaustion markers during therapy. \u003c/strong\u003eFlow cytometry analysis of peripheral blood immune cells before and during treatment (Cycle 1) and end of treatment. (\u003cstrong\u003eA,B\u003c/strong\u003e) Box-and-whisker plots of percentage of T-cells, B-cell, NK cells, and Treg cells (A, left), CD4\u003csup\u003e+\u003c/sup\u003e, and CD8\u003csup\u003e+\u003c/sup\u003e T-cells (A, right) and memory subset frequency in CD4\u003csup\u003e+\u003c/sup\u003e and CD8\u003csup\u003e+\u003c/sup\u003e T-cells (\u003cstrong\u003eB\u003c/strong\u003e). (\u003cstrong\u003eC\u003c/strong\u003e) Change in activation (HLA-DR+CD38\u003csup\u003e+\u003c/sup\u003e, NKG2D, 41BB) and exhaustion (PD-1, TIM-3, TIGIT) markers among CD4\u003csup\u003e+\u003c/sup\u003e and CD8\u003csup\u003e+\u003c/sup\u003e T-cells. *p \u0026lt; 0.05; **p \u0026lt; 0.01; ***p \u0026lt; 0.001; ns: not significant\u003c/p\u003e\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"Figure4.png","url":"https://assets-eu.researchsquare.com/files/rs-1852342/v1/0358943310417b119a2ca6d8.png"},{"id":24157802,"identity":"47f33179-ff95-4a45-9415-bd020e841a64","added_by":"auto","created_at":"2022-07-21 17:32:15","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":199194,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eFlow cytometry of exhaustion markers in long-term responders and others\u003c/strong\u003e. (\u003cstrong\u003eA\u003c/strong\u003e) Pie chart of the expression pattern of five exhaustion markers (CTLA-4, LAG-3, PD-1, TIGIT, and TIM-3) in the two groups before and after therapy (EOT). The pie charts represent the average frequencies of cells expressing the combination of the five exhaustion markers analyzed. The segments within the chart denote populations expressing different combinations of markers, and the pie segment’s size correlates to the particular population’s frequency. The arcs around the circumference indicate the particular exhaustion marker produced by the proportion of cells under the arc. (\u003cstrong\u003eB\u003c/strong\u003e) Analysis of\u003cstrong\u003e \u003c/strong\u003eTIM-3 and LAG-3 expression in CD4\u003csup\u003e+\u003c/sup\u003e and CD8\u003csup\u003e+\u003c/sup\u003e T-cells. (\u003cstrong\u003eC\u003c/strong\u003e) Change of CD4\u003csup\u003e+\u003c/sup\u003e/CD8\u003csup\u003e+\u003c/sup\u003e T-cell ratio. (\u003cstrong\u003eC\u003c/strong\u003e) Ratio of CD4\u003csup\u003e+\u003c/sup\u003e T-cells/CD8\u003csup\u003e+\u003c/sup\u003e T-cells in long-term responders whose response was prolonged over 12 months and others. *\u003cem\u003ep \u003c/em\u003e\u0026lt; 0.05; **\u003cem\u003ep \u003c/em\u003e\u0026lt; 0.001.\u003c/p\u003e\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"Figure5.png","url":"https://assets-eu.researchsquare.com/files/rs-1852342/v1/345c982acaf1a6b50ec69a30.png"},{"id":24911208,"identity":"bea2b2f2-0145-4c7b-b923-48cb4a31bceb","added_by":"auto","created_at":"2022-08-08 10:32:28","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1202565,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-1852342/v1/3db1627b-9062-4542-a416-c6bcf4f7ab8f.pdf"},{"id":24157804,"identity":"5075450a-c95e-40bf-bdb9-734f15261ea8","added_by":"auto","created_at":"2022-07-21 17:32:15","extension":"pdf","order_by":9,"title":"","display":"","copyAsset":false,"role":"supplement","size":368760,"visible":true,"origin":"","legend":"","description":"","filename":"Supplementaryfiles.pdf","url":"https://assets-eu.researchsquare.com/files/rs-1852342/v1/787aeaeeaa6338cd65936552.pdf"}],"financialInterests":"The authors have declared there is \u003cb\u003eNO\u003c/b\u003e conflict of interest to disclose.","formattedTitle":"Phase I study: safety and efficacy of ex vivo-expanded allogeneic natural killer cells (MG4101) with rituximab for relapsed/refractory B-cell non-Hodgkin lymphoma","fulltext":[{"header":"Introduction","content":"\u003cp\u003eDespite improved treatment outcomes for non-Hodgkin lymphoma (NHL), prognosis remains poor, with an unmet need for novel therapies [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Rituximab is the cornerstone for treating B-cell NHL, and attempts have been made to enhance its clinical benefits by combining with chemotherapy or cell therapy, such as natural killer (NK) cell treatment. Rituximab is used for antibody-dependent cell-mediated cytotoxicity (ADCC) therapy that requires immune cells to induce anti-tumor cytotoxicity activated by antibodies linked to target cells. It triggers innate immune responses and cytotoxicity in tumor cells and induces pro-inflammatory cytokine production to rapidly stimulate adaptive immune responses [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eTisagenlecleucel, a chimeric antigen receptor T cell T-cell (CAR-T) therapy, is remarkably effective and has exhibited durable clinical response in treating B-cell NHL in phase II clinical trials. However, grade 3/4 treatment-related adverse events occurred in 77% of patients, and life-threatening toxicities were also reported [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Furthermore, tisagenlecleucel failed to improve survival in patients with aggressive, relapsed, or refractory NHL [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eNK cells are innate lymphoid immune cells that contribute to anti-tumor responses, preventing tumor growth and dissemination. Adoptive transfer of autologous NK cells is safe, albeit ineffective, with an impaired capacity to mediate direct cytotoxic and antibody-mediated killing [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Haploidentical donor NK cells with rituximab is promising against advanced NHL [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Additionally, allogeneic NK cells have been proposed as an effective therapeutic option [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Adoptive allogeneic NK cell therapy in a non-transplant setting is well tolerated and efficacious in lymphoid malignancies, suggesting that it is effective for overcoming an immunosuppressive tumor microenvironment [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eMG4101, a novel therapeutic agent, consists of cryopreserved, \u003cem\u003eex vivo\u003c/em\u003e-expanded allogeneic and highly activated NK cells. It was generated from the KIR B/x haplotype in unrelated healthy individuals with a higher affinity for the hFcγRIIIa\u003csub\u003eV158\u003c/sub\u003e variant. MG4101 is safe and could influence immune responses through the activation of T-cells and inhibition of suppressive cells and molecules, despite having a relatively short persistence (4 days) [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Combination of MG4101 and rituximab led to higher survival rates than rituximab monotherapy in a murine lymphoma model [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. In this phase I study, we evaluated the safety and preliminary efficacy of MG4101 in combination with rituximab in patients with relapsed/refractory B-cell NHL (r/rNHL).\u003c/p\u003e"},{"header":"Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy design and patient eligibility\u003c/h2\u003e \u003cp\u003eEligible patients were \u0026ge;\u0026thinsp;19 years old with confirmed r/rNHL of B-cell origin (mature B-cell lymphoma according to the World Health Organization, Geneva [WHO]). Patients were required to have an Eastern Cooperative Oncology Group performance status of 0 or 1; life expectancy\u0026thinsp;\u0026ge;\u0026thinsp;3 months; adequate hematologic, hepatic, and renal functions based on appropriate tests; immunophenotyping indicating CD20-positive status, toxicities due to prior treatments that were stable; recovery from toxicities of Common Terminology Criteria for Adverse Events (CTCAE) grade\u0026thinsp;\u0026le;\u0026thinsp;1, except for clinically non-significant toxicities, such as alopecia.\u003c/p\u003e \u003cp\u003e \u003cstrong\u003eInformed consent\u003c/strong\u003e \u003cp\u003ewas obtained from all patients. The trial was conducted in accordance with the International Conference on Harmonization Good Clinical Practice guidelines and applicable local regulatory requirements and laws. The clinical protocol was in accordance with Helsinki Declaration of 1975 and approved by the Korean Ministry of Food and Drug Safety (protocol number: MG4101-NHL-P1; October 2, 2018).\u003c/p\u003e \u003c/p\u003e \u003cp\u003eThis dose-escalation study followed a classic 3\u0026thinsp;+\u0026thinsp;3 design to evaluate the maximum tolerated dose (MTD) (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). No patient received an escalated dose until at least three patients had received the previous dose and had been assessed for dose-limiting toxicity (DLT). Doses escalated in cohorts of three patients showed that no MG4101-related DLT occurred in cycle 1. Each cycle lasted 4 weeks and the initial component of phase I consisted of six cycles. Additional treatment for up to eight cycles was allowed as maintenance therapy in the extension component of phase I.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eTreatment\u003c/h2\u003e \u003cp\u003eIn a previous single-centre phase I dose-escalation study of MG4101 in patients with previously treated malignant lymphoma, or advanced, recurrent solid tumors, a dose of 3 \u0026times; 10\u003csup\u003e7\u003c/sup\u003e cells/kg administered intravenously was considered the maximum feasible dose (MFD) because of the lack of DLT [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Therefore, here, the three cohorts received MG4101 at the following doses: 1 \u0026times; 10\u003csup\u003e7\u003c/sup\u003e (level 1), 3 \u0026times; 10\u003csup\u003e7\u003c/sup\u003e (level 2), and 9 \u0026times; 10\u003csup\u003e7\u003c/sup\u003e cells/kg (level 3). MG4101 was administered every 2 weeks, beginning at least 1 h after the first dose of rituximab (375 mg/m\u003csup\u003e2\u003c/sup\u003e, intravenously) for the first six cycles (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Interval of MG4101 infusion was determined based on persistence of NK cells, pharmacokinetic results of a previous phase I trial, and half-life of rituximab [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. Interleukin (IL)-2 was administered subcutaneously at 1 \u0026times; 10\u003csup\u003e6\u003c/sup\u003e IU/m\u003csup\u003e2\u003c/sup\u003e/day, at least 1 h after MG4101 administration, to enhance NK cell expansion. During the maintenance therapy (cycles 7‒14), MG4101 was administered only on the first day of each cycle, and IL-2 was not administered. Rituximab was administered weekly for the first two cycles and then on the first day of cycles 3‒14. For lymphodepletion, fludarabine (20 mg/m\u003csup\u003e2\u003c/sup\u003e) plus cyclophosphamide (250 mg/m\u003csup\u003e2\u003c/sup\u003e) was administered intravenously for three days before rituximab in cycles 1, 3, and 5.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eEndpoints and assessments\u003c/h2\u003e \u003cp\u003eThe primary endpoint was the MTD of MG4101 in combination with rituximab. In cases where MTD was not reached, MFD was used. MFD was defined as the dose administered to maximize exposure. MTD was defined as the highest dose with which six patients had been treated with less than two occurrences of DLT. DLT was defined as any treatment-related toxicity of CTCAE grade\u0026thinsp;\u0026ge;\u0026thinsp;3 and graft-versus-host disease (GVHD) of grade\u0026thinsp;\u0026ge;\u0026thinsp;3. DLTs were assessed during cycle 1, including the first two doses of the investigational agent.\u003c/p\u003e \u003cp\u003eThe secondary endpoints included the objective response rate (ORR) according to the investigator\u0026rsquo;s assessment, complete response (CR), and partial response (PR), determined between the start of treatment and up to six cycles. Overall survival, time-to-progression (TTP), and time-to-response were additional secondary endpoints. Responses were evaluated using computed tomography (CT) or positron emission tomography (PET)-CT. Radiological assessments were performed locally, according to the Lugano classification for NHL [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eAdditional endpoints included assessing adverse events according to CTCAE version 5.0, GVHD assessment, and allogeneic antibody generation. Exploratory evaluations included immunological assays, MG4101 pharmacokinetics, and human leukocyte antigen-killer-cell immunoglobulin-like receptor (HLA-KIR) analysis between donor and subject.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eImmunostaining and flow cytometry\u003c/h2\u003e \u003cp\u003eFlow cytometry analysis of changes in immune cell populations and various activation/exhaustion markers after MG4101 administration was performed on serially acquired peripheral blood mononuclear cells (PBMCs). Antibodies used to assess the proportion of memory T cells are listed in Table S2. Stained cells were acquired on LSRFortessa (BD Biosciences, San Jose, CA, USA), and data were analyzed using FlowJo software (FLOWJO, LLC, Ashland, OR, USA).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003eCytokine measurements\u003c/h2\u003e \u003cp\u003eBlood samples were collected at specific time points for cytokine analyses and were immediately centrifuged ( 800 \u0026times; g, 10 min, 4\u0026deg;C), divided into aliquots, and stored at \u0026minus;\u0026thinsp;80\u0026deg;C for subsequent analysis. Serum (IL-6, IL-8, IL-10, transforming growth factor-β1 (TGF-β1), tumor necrosis factor-α (TNF-α), and C-reactive protein (CRP) levels were measured using a sandwich enzyme-linked immunosorbent assay with Quantikine kits (R\u0026amp;D Systems, Minneapolis, MN, USA). Limit of detection for the cytokines was defined according to the manufacturer\u0026rsquo;s instructions (IL-1β/12p70/-17, TNF-α, and IFN-γ: 2.0 ng/mL; IL-6/-4/-10: 1.0 ng/mL).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003ePharmacokinetics\u003c/h2\u003e \u003cp\u003ePharmacokinetic analysis of MG4101 was performed by confirming the presence of donor DNA in the patients\u0026rsquo; blood through nested polymerase chain reaction (PCR) at various time points. Nested PCR was performed to detect the presence of allo-HLA-DRB1 genes of donor NK cell origin as described previously [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analyses\u003c/h2\u003e \u003cp\u003eStatistical analyses were conducted using SAS software (version 9.4; SAS Institute Inc., Cary, NC, USA). Descriptive statistics were determined for demographic and baseline data, including mean, standard deviation, median, and range for continuous variables and frequency and percentage for categorical data. Statistical significance was set at two-sided \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05. ORRs are presented with Clopper\u0026ndash;Pearson\u0026rsquo;s 95% confidence interval (CI) on both sides, and Kaplan\u0026ndash;Meier method was used for time-to-event analyses. Paired \u003cem\u003et\u003c/em\u003e-test or Wilcoxon signed-rank test was used for intragroup comparisons in exploratory immunological analyses.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003ePatient characteristics and treatment\u003c/h2\u003e \u003cp\u003eThis study was conducted at three tertiary cancer centres in South Korea between April 2019 and October 2020. Baseline characteristics of the nine patients who participated herein are summarized in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e and Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. Median age of the patients was 64 (range: 38.0‒80.0) years, most patients were male (78%), and six patients (67%) had received\u0026thinsp;\u0026ge;\u0026thinsp;4 prior systemic therapy regimens. Three patients (33%) had received prior autologous stem cell transplantation.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eDemographic and baseline characteristics (n\u0026thinsp;=\u0026thinsp;9)\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCharacteristics\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLevel 1\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;3)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eLevel 2\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;3)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eLevel 3\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;3)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;9)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eMedian age at baseline, years (range)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e64 (38‒80)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e61 (56‒69)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e66 (57\u0026ndash;80)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e64 (38‒80)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eGender, n (%)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2 (66.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2 (66.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3 (100)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e7 (77.8)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (33.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (33.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2 (22.2)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eBaseline ECOG PS, n (%)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2 (66.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2 (66.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4 (44.4)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (33.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3 (100)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1 (33.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e5 (55.6)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003ePathologic subtypes, n (%)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDiffuse large B-cell lymphoma\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2 (66.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3 (100)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1 (33.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e6 (66.7)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFollicular lymphoma\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMantle cell lymphoma\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (33.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1 (33.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2 (22.2)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMarginal zone lymphoma\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1 (33.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1 (11.1)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eNo. of prior systemic therapy regimens, n (%)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (33.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (33.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2 (22.2)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (33.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1 (11.1)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u0026ge;\u0026thinsp;4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (33.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2 (66.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3 (100)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e6 (66.7)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eInternational Prognostic Index (IPI), n (%)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLow Risk\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1 (33.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1 (11.1)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLow-Intermediate Risk\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2 (66.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (33.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3 (33.3)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHigh-Intermediate Risk\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (33.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1 (33.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2 (22.2)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHigh Risk\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (33.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (33.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1 (33.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3 (33.3)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eOther prior anti-cancer treatment, n (%)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePrior radiation therapy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2 (66.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (33.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1 (33.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4 (44.4)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePrior hematopoietic stem cell transplantation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (33.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (33.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1 (33.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3 (33.3)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003eAbbreviations: ECOG PS, Eastern Cooperative Oncology Group performance status\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003ePatient disposition and regimen design are shown in Figs.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e and \u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, respectively. Three patients were assigned to each MG4101 dose level, and all nine patients completed at least one cycle. Eight patients (88.9%) discontinued the study before completing cycle 6. One patient received maintenance therapy after cycle 6, but treatment was discontinued after cycle 7. All patients were evaluated for efficacy, safety, and exploratory endpoints.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003eSafety and tolerability\u003c/h2\u003e \u003cp\u003eTreatment was well-tolerated, and most treatment-emergent adverse events (TEAEs) were grade 1 or 2 (68.9%). Drug-related TEAEs occurred in 89% of the patients; most common were grade 1\u0026ndash;2 neutropenia and pyrexia. One patient experienced grade 1 cytokine release syndrome (CRS), and neurotoxicity was not observed. The most common adverse events were neutropenia, thrombocytopenia, pyrexia, and nausea (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). The most common grade\u0026thinsp;\u0026ge;\u0026thinsp;3 TEAE was neutropenia (\u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;6); three patients experienced febrile neutropenia. One level 1 patient experienced \u003cem\u003ePneumocystis jirovecii\u003c/em\u003e pneumonia, which led to treatment discontinuation. However, GVHD, treatment-related mortality, and DLTs were not observed. As there was no treatment-emergent DLT in the nine participants at any dose, the MFD was set at the highest dose (9 \u0026times; 10\u003csup\u003e7\u003c/sup\u003e cells/kg).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eTreatment-emergent adverse events (TEAEs) reported in \u0026ge;\u0026thinsp;2 cases.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"9\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eTEAE, n (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eLevel 1\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;3)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003eLevel 2\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;3)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c7\" namest=\"c6\"\u003e \u003cp\u003eLevel 3\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;3)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;9)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eGrade 1\u0026ndash;2\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cem\u003eGrade 3\u0026ndash;4\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003eGrade 1\u0026ndash;2\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003eGrade 3\u0026ndash;4\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cem\u003eGrade 1\u0026ndash;2\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u003cem\u003eGrade 3\u0026ndash;4\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003e\u003cem\u003eGrade 1\u0026ndash;2\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003e\u003cem\u003eGrade 3\u0026ndash;4\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"9\" nameend=\"c9\" namest=\"c1\"\u003e \u003cp\u003eHematologic AE\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAnaemia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e1 (11.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e1 (11.1)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNeutrophil count decrease\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e2 (22.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e5 (55.6)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePlatelet count decrease\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e1 (11.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e1 (11.1)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFebrile neutropenia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e2 (22.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e3 (33.3)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"9\" nameend=\"c9\" namest=\"c1\"\u003e \u003cp\u003eNon-hematologic AE\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePyrexia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e5 (55.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCytokine Release Syndrome\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e1 (11.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHypotension\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e1 (11.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e1 (11.1)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCough\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e1 (11.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNausea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e4 (44.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e1 (11.1)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDyspnoea\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e1 (11.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e1 (11.1)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDecreased appetite\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e3 (33.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e2 (22.2)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFatigue\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e2 (22.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHypersensitivity\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e1 (11.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e1 (11.1)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGastrointestinal disorder\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e2 (22.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVomiting\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e2 (22.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003eEfficacy\u003c/h2\u003e \u003cp\u003eORR was 55.6%; four patients achieved PR (3 DLBCL, 1 MCL), one achieved CR (1 MZL), and four showed PD (3 DLBCL, 1 MCL) (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eA and Table S1). Responses were observed across all three doses: 2 PR at level 1, 1 PR at level 2, 1 PR and 1 CR at level 3. Median time for response (\u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;5) was 60.0 days (95% CI: 22.0\u0026ndash;100.0) and median duration of response (\u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;5) was 45.0 (range: 22.0‒806.0) days (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eB). Notably, a continued response over 806 days was observed in patient 8203106, who achieved CR at level 3 (cut-off date: 2022-03-31) (Figs.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eA and \u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eC). Eight patients experienced PD, and median TTP was 50.0 days (95% CI: 22.0\u0026ndash;355.0). Overall median survival time in level 2 was 72.0 days (95% CI: 69.0\u0026ndash;75.0).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003eGeneration of allogeneic antibodies and pharmacokinetics\u003c/h2\u003e \u003cp\u003eIn the antibody HLA Class I and II measurements between donors and subjects, the donor-specific antibody, HLA Cw15, was detected in one patient (Level 3: 8203106). MG4101 persisted for up to 7 days in seven patients and 14 days in two patients (Table S3).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec15\" class=\"Section2\"\u003e \u003ch2\u003eImmunological assessments\u003c/h2\u003e \u003cp\u003eWe examined changes in immune cell frequencies at baseline, during cycle 1, and at the end of treatment (EOT). The proportion of CD19\u003csup\u003e+\u003c/sup\u003e B-cells was low (\u0026lt;\u0026thinsp;1%) throughout the treatment. The percentage of CD3\u003csup\u003e\u0026minus;\u003c/sup\u003eCD56\u003csup\u003e+\u003c/sup\u003e NK cells and regulatory T-cells (CD4\u003csup\u003e+\u003c/sup\u003eFoxp3\u003csup\u003e+\u003c/sup\u003eCD127\u003csup\u003elow\u003c/sup\u003e) did not change during the treatment (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eA). The proportion of CD3\u003csup\u003e+\u003c/sup\u003e T-cells significantly increased after treatment (26.53\u0026thinsp;\u0026plusmn;\u0026thinsp;28.88%, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.0249), mainly due to an increase in the CD8\u003csup\u003e+\u003c/sup\u003e T-cell population (46.62\u0026thinsp;\u0026plusmn;\u0026thinsp;228.6%, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.0003), resulting in a lower ratio of CD4\u003csup\u003e+\u003c/sup\u003e T cells/CD8\u003csup\u003e+\u003c/sup\u003e T-cells than the baseline (2.38\u0026thinsp;\u0026plusmn;\u0026thinsp;0.89 vs. 0.53\u0026thinsp;\u0026plusmn;\u0026thinsp;0.61, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.0007) (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eA). While the percentage of na\u0026iuml;ve and central memory cells (Tcm) was reduced (Na\u0026iuml;ve: 9.69% \u0026plusmn; 10.99% \u0026rarr; 3.56% \u0026plusmn; 6.53%, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.0315; Tcm: 43.36% \u0026plusmn; 21.90% \u0026rarr; 19.63% \u0026plusmn; 19.92%, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.0244), that of the effector memory subtypes (Tem, Temra) was increased (Tem: 45.81% \u0026plusmn; 19.54% \u0026rarr; 72.63% \u0026plusmn; 20.39%, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.0078; Temra: 1.16% \u0026plusmn; 2.04% \u0026rarr; 4.18% \u0026plusmn; 4.71%, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.0034) among CD4\u003csup\u003e+\u003c/sup\u003e T cells. Similar results were observed for CD8\u003csup\u003e+\u003c/sup\u003e T cells, in which effector memory cells were the predominant subset after treatment (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eB).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eWe analyzed the expression profiles of key activation (HLA-DR\u003csup\u003e+\u003c/sup\u003eCD38\u003csup\u003e+\u003c/sup\u003e, NKG2D, 41BB, and CTLA-4) and exhaustion (PD-1, TIGIT, TIM-3, and LAG-3) molecules in T cells. Treatment significantly increased their levels. HLA-DR\u003csup\u003e+\u003c/sup\u003eCD38\u003csup\u003e+\u003c/sup\u003e, NKG2D, and 41BB were activated at early time points, which diminished over time; TIM-3 and TIGIT expression increased and was maintained until EOT (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eC). Exceptionally, CTLA-4 expression was decreased in CD8\u003csup\u003e+\u003c/sup\u003e T cells, whereas LAG-3 expression was unaffected.\u003c/p\u003e \u003cp\u003eCytokine levels were analyzed at each visit among the dose groups (Figure S1); no evidence of cytokine storm (or CRS) throughout the treatment was noted.\u003c/p\u003e \u003cp\u003eFurther exploratory immunological assessment focused on five exhaustion markers (CTLA-4, LAG-3, PD-1, TIGIT, and TIM-3) between long-term responders whose response lasted over 12 months (8203101 in level 1 and 8203106 in level 3) and others at various time points. Interestingly, short-term responders or non-responders had a greater frequency and showed multiple expressions of these markers than long-term responders (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003eA). Notably, LAG-3 and TIM-3 expression was low from the start to the EOT (LAG-3\u003csup\u003e+\u003c/sup\u003e/CD4\u003csup\u003e+\u003c/sup\u003e: 0.36% vs. 5.039%, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.046; LAG-3\u003csup\u003e+\u003c/sup\u003e/CD8\u003csup\u003e+\u003c/sup\u003e: 0.56% vs. 3.914%, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.232; TIM-3\u003csup\u003e+\u003c/sup\u003e/CD4\u003csup\u003e+\u003c/sup\u003e: 6.39% vs. 17.87%, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.094; TIM-3\u003csup\u003e+\u003c/sup\u003e/CD8\u003csup\u003e+\u003c/sup\u003e: 13.6% vs. 22.53%, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.290), rendering the immune environment favorable for long-term responders (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003eB). Furthermore, the CD4\u003csup\u003e+\u003c/sup\u003e/CD8\u003csup\u003e+\u003c/sup\u003e T-cell ratio, an indicator of cellular immune function, was notably high in long-term responders (1.102 vs. 0.259, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.000029); inversely, the ratio decreased rapidly in others, from 2.461 to 0.259 (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003eC).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec16\" class=\"Section2\"\u003e \u003ch2\u003eAnalysis of the donors and subjects for HLA-KIR\u003c/h2\u003e \u003cp\u003eFour (44.4%) patients had one KIR mismatch, and five (55.6%) had two KIR mismatches (Table S4). However, there was no significant difference in the number of mismatched KIRs or activating KIRs between responders and non-responders (mismatched KIR, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;1; activating KIRs, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.5238).\u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis phase I trial demonstrated that the combination of MG4101 and rituximab was well tolerated in patients with heavily pre-treated r/rNHL, with an encouraging response rate (55.6%). The best response was stable disease in a previous phase I study of MG4101 in patients with r/rNHLs or solid metastatic tumors, although the MFD was lower than that herein [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Compared with the previous trial, this study combined rituximab and the high-affinity CD16 158V variant of NK cells with haplotype B after lymphodepleting chemotherapy with fludarabine and cyclophosphamide. Patients expressing the high-affinity hFcγRIIIa\u003csub\u003eV158\u003c/sub\u003e variant reportedly showed good clinical outcomes with rituximab or trastuzumab than those homozygous for the lower-affinity hFcγRIIIa\u003csub\u003eF158\u003c/sub\u003e variant [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Moreover, a preparative regimen of fludarabine plus cyclophosphamide is known to deplete host cells and prolong the persistence of administered cells. Furthermore, rituximab combined with MG4101 acted synergistically with ADCC. Therefore, these factors may have contributed to the higher response rates observed herein.\u003c/p\u003e \u003cp\u003eCombination therapy is associated with the reversal of the tumor microenvironment, which provides a favorable microenvironment that better supports anti-tumor immunity. The tumor microenvironment plays an essential role in the disease course and clinical outcomes after NHL [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. MG4101 plus rituximab regulates both innate and adaptive immunity by increasing the proportion of T-cell subsets with effector memory and upregulating activation and exhaustion markers on T cells, leading to immune response activation. Particularly, HLA-DR\u003csup\u003e+\u003c/sup\u003eCD38\u003csup\u003e+\u003c/sup\u003e and NKG2D upregulation in CD8\u003csup\u003e+\u003c/sup\u003e T-cells may be associated with memory cell differentiation. In line with the increase in the proportion of effector memory T cells, these results suggest that MG4101 plus rituximab induces early T-cell activation and shifts the immune response to late activation/exhaustion and differentiation status. Evidence indicates that NK cells contribute to adaptive immunity through crosstalk with other immune cells, including T cells, B cells, and dendritic cells (DCs). NK cells promote Th1 polarization through IFN-γ production and indirectly enhance adaptive T-cell response by promoting DC maturation [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. These therapeutic responses to MG4101 plus rituximab combination were associated with peripheral blood circulating activated T-cells and mature DCs.\u003c/p\u003e \u003cp\u003eExploratory analysis of long-term versus short-term responders have focused on the expression of T-cell exhaustion markers [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. Long-term responders tended to have lower expression of exhaustion markers than short-term responders when expressions before and after treatment were compared. Thus, a less-exhausted immune environment and functional cellular response may contribute to better responses in long-term responders to MG4101 plus rituximab. Although this trial involved a relatively small cohort, low expression of exhaustion markers, particularly LAG-3 and TIM-3, was likely related to the therapeutic effect. Low expression of exhaustion markers in patient PBMCs implies that it can prevent the \u0026lsquo;off\u0026rsquo; signal from being sent, allowing the T-cells to kill tumor cells, turning immunologically \u0026lsquo;cold tumors\u0026rsquo; to \u0026lsquo;hot tumors\u0026rsquo;. Furthermore, a high CD4\u003csup\u003e+\u003c/sup\u003e:CD8\u003csup\u003e+\u003c/sup\u003e ratio was observed in long-term responders compared with that in other patients [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. Low expression of exhaustion markers, together with a high CD4\u003csup\u003e+\u003c/sup\u003e:CD8\u003csup\u003e+\u003c/sup\u003e ratio, could be a favorable predictive biomarker of a good response in patients with r/rNHL. However, further investigations with a larger cohort are needed to draw firm conclusions. Production of donor-specific HLA antibodies (DSA) might affect the persistence of NK cells, leading to a decreased response. DSA was detected in patients with solid tumors after NK infusion without a preparative regimen [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. However, most patients did not develop DSA, which might be related to lymphodepleting chemotherapy. Additionally, MG4101 was detected for up to 2 weeks, compared with 3 or 4 days in a previous study that did not incorporate any lymphodepleting treatment [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe safety and efficacy of NK cell therapy have been demonstrated in both autologous and allogeneic haploidentical settings [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. Autologous NK cells combined with rituximab have shown promising results, with over 70% of patients maintaining CR [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. However, it is difficult to prove the exact contribution of NK cells to the CR because most patients received chemotherapy after autologous NK cell treatment. Interestingly, herein, one patient (8203106) switched from PR to CR despite no additional treatment after trial completion. This provides evidence favoring the adoptive transfer of unrelated allogeneic NK cells concomitantly with rituximab for a better immune response, with manageable safety profile and preliminary efficacy in patients with r/rNHL. Safety is the major advantage of NK cell therapies. Clinical studies have shown promising tumor regression responses without severe adverse events [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. Additionally, allogeneic NK cell treatment is known to exert a strong graft-versus-tumor effect without GVHD development [\u003cspan additionalcitationids=\"CR24 CR25 CR26 CR27 CR28\" citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]. Induction of remission in more than 25% of patients with highly refractory NHL by haploidentical NK cells [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e] spurred the development of donor NK cell therapy for advanced NHL. Given the previous successful leukemia treatment with alloreactive haploidentical KIR ligand-mismatched NK cells [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e], it was expected that MG4101 would be safe and enhance clinical benefit in patients with r/rNHL. CD19-directed CAR-T-cells are currently approved for r/rNHL. Nevertheless, severe CRS or neurotoxicities were noted in a considerable proportion of patients [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. MG4101 prepared from healthy non-HLA-matched individuals was well tolerated with no signs of cytokine storm, neurotoxicity, or GVHD, unlike CAR-T-cell therapy. Only one patient experienced grade 1 CRS, which was self-limiting, and none developed neurotoxicities. Immunological assays also showed no evidence of elevated cytokine levels, consistent with other findings suggesting an absence of a cytokine storm or CRS with NK cell treatment [\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e]. For allogeneic NK cell therapy, strategies including the use of the higher affinity hFcγRIIIa\u003csub\u003eV158\u003c/sub\u003e variant of KIR B/x haplotype with lymphodepleting chemotherapy could be promising options for improving clinical efficacy in the antibody combination therapeutic setting as an off-the-shelf product.\u003c/p\u003e \u003cp\u003eThis clinical study demonstrated that combination treatment with MG4101 and rituximab is feasible, yielding a favorable safety profile and encouraging response rates in patients with r/rNHL.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgments: \u003c/strong\u003eUnder the authors\u0026rsquo; guidance, medical writing support was provided by Greg Plosker and David Figgitt, Ph.D., ISMPP CMPP\u0026trade;, and Content Ed Net. We thank the investigators, site support staff, and the patients who participated in this study. This work was supported by the GC Cell Corp., South Korea.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contributions: \u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eConception and design: Dok Hyun Yoon\u003c/p\u003e\n\u003cp\u003eDevelopment of methodology: Dok Hyun Yoon, Youngil Koh, Won Seog Kim, Eui-Cheol Shin\u003c/p\u003e\n\u003cp\u003eAcquisition of data: Dok Hyun Yoon, Youngil Koh, Won Seog Kim\u003c/p\u003e\n\u003cp\u003eAnalysis and interpretation of data: Dok Hyun Yoon, Youngil Koh, Miyoung Jung\u003c/p\u003e\n\u003cp\u003eWriting, review, and revision of the manuscript: Dok Hyun Yoon, Youngil Koh, and Yu Kyeong Hwang\u003c/p\u003e\n\u003cp\u003eAdministrative, technical, or material support: Miyoung Jung, Jeong-Eun Kwak\u003c/p\u003e\n\u003cp\u003eStudy supervision: Won Seog Kim\u003c/p\u003e\n\u003cp\u003eOther (study conduction): Dok Hyun Yoon, Youngil Koh, Won Seog Kim\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflicts of interest: \u003c/strong\u003eThe authors have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData sharing statement: \u003c/strong\u003eThe data generated during the study are available from the corresponding author on reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eRovira J, Valera A, Colomo L, Setoain X, Rodr\u0026iacute;guez S, Mart\u0026iacute;nez-Trillos A, \u003cem\u003eet al\u003c/em\u003e. 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Cancer Cell. 2020; 37: 426\u0026ndash;427.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-1852342/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-1852342/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eMG4101, an \u003cem\u003eex vivo\u003c/em\u003e-expanded allogeneic natural killer cell, can enhance rituximab antibody-dependent cytotoxicity in relapsed/refractory B-cell non-Hodgkin lymphoma (r/rNHL). Its safety and efficacy were assessed in this phase I trial. Patients received escalating doses of intravenous MG4101 every 2 weeks plus rituximab. Interleukin-2 was administered subcutaneously after MG4101 treatment. Fludarabine plus cyclophosphamide was administered intravenously before rituximab in cycles 1, 3, and 5. A 3\u0026thinsp;+\u0026thinsp;3 design was used to determine the maximum tolerated dose (MTD) and maximum feasible dose (MFD). Assessments were performed over a six-cycle period, with an extended maintenance period of up to eight cycles. Nine patients received three different doses of MG4101 and rituximab. MTD could not be determined because of the absence of dose-limiting toxicity. Treatment-related adverse events, mostly grade 1 or 2, occurred in 89% patients. Only one patient experienced grade 1 cytokine release syndrome. MG4101 persisted for at least 7 days in seven patients. Four patients achieved a partial response, and one attained a complete response, yielding a 55.6% response rate. Two patients showed prolonged responses and low exhaustion marker levels in T cells. MG4101 plus rituximab presented a favorable safety profile and overall response rate in patients with r/rNHL.\u003c/p\u003e","manuscriptTitle":"Phase I study: safety and efficacy of ex vivo-expanded allogeneic natural killer cells (MG4101) with rituximab for relapsed/refractory B-cell non-Hodgkin lymphoma","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2022-07-21 17:32:13","doi":"10.21203/rs.3.rs-1852342/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"6cef32ff-7905-402b-8d5e-8b7774970c9c","owner":[],"postedDate":"July 21st, 2022","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2022-08-08T10:32:19+00:00","versionOfRecord":[],"versionCreatedAt":"2022-07-21 17:32:13","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-1852342","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-1852342","identity":"rs-1852342","version":["v1"]},"buildId":"-HB7Z8yhvgn0wM9Nzuekk","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}