Preventing trogocytosis by cathepsin B inhibition augments CAR T cell function.

Chimeric antigen receptor (CAR) T cell therapy has shown remarkable efficacy in cancer treatment. Still, most patients receiving CAR T cells relapse within 5 years of treatment. CAR-mediated trogocytosis (CMT) is a potential tumor escape mechanism in which cell surface proteins transfer from tumor cells to CAR T cells. CMT results in the emergence of antigen-negative tumor cells, which can evade future CAR detection, and antigen-positive CAR T cells, which is hypothesized to lead to CAR T cell fratricide and dysfunction. Using a system to selectively degrade trogocytosed antigen in CAR T cells, we show that the presence of trogocytosed antigen in CAR T cells directly causes CAR T cell fratricide and exhaustion. By performing a small molecule screening using a custom high throughput CMT-screening assay, we identified the cysteine protease cathepsin B (CTSB) as a key driver of CMT. We show that overexpression of cystatin A (CSTA), an endogenous human inhibitor of CTSB, reduces trogocytosis resulting in prolonged antitumor activity and increased CAR T cell expansion/persistence. Overall, we show that targeting CMT is an effective approach to enhance CAR T cell function, which may improve their clinical efficacy.

A Clinical Perspective on Plasma Cell Leukemia: A Single-Center Experience.

Circulating plasma cells (CPCs) are detected in most multiple myeloma (MM) patients, both at diagnosis and on relapse. A small subset, plasma cell leukemia (PCL), represents a different biology and has a poor prognosis. In this retrospective analysis, we evaluated patients with primary (pPCL, n = 35) or secondary (sPCL, n = 49), with ≥5% CPCs and a smaller subset with lower CPCs of 1-4% (n = 20). The median age was 61 years; 45% were men and 54% were Black. High-risk cytogenetics were found in 87% and extramedullary disease in 47%. For the entire cohort, 75% received a proteasome inhibitor, 70% chemotherapy, 54% an immunomodulatory drug, 24% a daratumumab-based regimen and 26% an autologous stem cell transplant (ASCT). The treatments marginally improved the overall survival (OS) for pPCL vs. sPCL (13 vs. 3.5 months p = 0.002). However, the 5-year survival for the whole cohort was dismal at 11%. High-risk cytogenetics, low platelets, extramedullary disease and high LDH were independently associated with poor outcomes. Further research is urgently needed to expand the treatment options and improve the outcomes in PCL.

Endothelial injury and dysfunction with emerging immunotherapies in multiple myeloma, the impact of COVID-19, and endothelial protection with a focus on the evolving role of defibrotide.

Patients with multiple myeloma (MM) were among the groups impacted more severely by the COVID-19 pandemic, with higher rates of severe disease and COVID-19-related mortality. MM and COVID-19, plus post-acute sequelae of SARS-CoV-2 infection, are associated with endothelial dysfunction and injury, with overlapping inflammatory pathways and coagulopathies. Existing treatment options for MM, notably high-dose therapy with autologous stem cell transplantation and novel chimeric antigen receptor (CAR) T-cell therapies and bispecific T-cell engaging antibodies, are also associated with endothelial cell injury and mechanism-related toxicities. These pathologies include cytokine release syndrome (CRS) and neurotoxicity that may be exacerbated by underlying endotheliopathies. In the context of these overlapping risks, prophylaxis and treatment approaches mitigating the inflammatory and pro-coagulant effects of endothelial injury are important considerations for patient management, including cytokine receptor antagonists, thromboprophylaxis with low-molecular-weight heparin and direct oral anticoagulants, and direct endothelial protection with defibrotide in the appropriate clinical settings.

Outcomes of subsequent antilymphoma therapies after second-line axicabtagene ciloleucel or standard of care in ZUMA-7.

ABSTRACT: The optimal management of patients with relapsed/refractory large B-cell lymphoma (LBCL) after disease progression or lack of response to second-line (2L) therapy remains unclear. Here, we report outcomes among patients who received subsequent antilymphoma therapy per investigator discretion separately by their randomized 2L arm in ZUMA-7, namely axicabtagene ciloleucel (axi-cel) vs standard of care (SOC). Progression-free survival (PFS) and overall survival (OS) were calculated from 3L therapy initiation. In the SOC arm, 127 of 179 randomized patients (71%) received 3L therapy. Median PFS among those who received 3L cellular immunotherapy (n = 68) vs those who did not (n = 59) was 6.3 vs 1.9 months, respectively; median OS was 16.3 vs 9.5 months, respectively. In the axi-cel arm, 84 of 180 randomized patients (47%) received 3L therapy. Median PFS among those who received 3L chemotherapy (n = 60) vs cellular immunotherapy (n = 8) was 1.7 vs 3.5 months, respectively; median OS was 8.1 months vs not reached, respectively. Of the 60 patients who received 3L chemotherapy, 10 underwent stem cell transplantation (SCT) after salvage chemotherapy. Median PFS was 11.5 vs 1.6 months, and median OS was 17.5 vs 7.2 months for those who did vs did not reach SCT, respectively. Eight patients received 3L cellular immunotherapy after 2L axi-cel. Of these, 6 patients received subsequent SCT in any line; all 6 were alive at data cutoff. These findings help inform subsequent treatment choices after 2L therapy failure for relapsed/refractory LBCL. The trial was registered at www.clinicaltrials.gov as #NCT03391466.

A novel multicolor fluorescent spot assay for the functional assessment of chimeric antigen receptor (CAR) T-cell products.

BACKGROUND AIMS: Chimeric antigen receptor (CAR) T-cell (CAR-T) therapies have revolutionized the treatment of B-cell lymphomas. Unfortunately, relapses after CD19-targeted CAR-T are relatively common and, therefore, there is a critical need for assays able to assess the function and potency of CAR-T products pre-infusion, which will hopefully help to optimize CAR-T therapies. We developed a novel multicolor fluorescent spot assay (MFSA) for the functional assessment of CAR-T products on a single-cell level, combining the numerical assessment of CAR-T products with their functional characterization. METHODS: We first used a standard single-cell interferon (IFN)-γ enzyme-linked immune absorbent spot assay to measure CD19-targeted CAR-T responses to CD19-coated beads. We then developed, optimized and validated an MFSA that simultaneously measures the secretion of combinations of different cytokines on a single CAR-T level. RESULTS: We identified IFN-γ/tumor necrosis factor-α/granzyme B as the most relevant cytokine combination, and we used our novel MFSA to functionally and numerically characterize two clinical-grade CAR-T products. CONCLUSIONS: In conclusion, we have developed a novel assay for the quantitative and functional potency assessment of CAR-T products. Our optimized MFSA is cost-effective, easy to perform, reliable, can be performed overnight, allowing for a fast delivery of the product to the patient, and requires relatively minimal maintenance and training. The clinical value of our novel assay will be assessed in studies correlating the pre-infusion assessment of CAR-T products with the patients' outcome in a prospective fashion.

Treatment of secondary CNS lymphoma using CD19-targeted chimeric antigen receptor (CAR) T cells.

BACKGROUND: Aggressive B cell lymphoma with secondary central nervous system (CNS) involvement (SCNSL) carries a dismal prognosis. Chimeric antigen receptor (CAR) T cells (CAR-T) targeting CD19 have revolutionized the treatment for B cell lymphomas; however, only single cases with CNS manifestations successfully treated with CD19 CAR-T have been reported. METHODS: We prospectively enrolled 4 patients with SCNSL into our study to assess clinical responses and monitor T cell immunity. RESULTS: Two of four SNCSL patients responded to the CD19-targeted CAR-T. Only one patient showed a substantial expansion of peripheral (PB) CAR-T cells with an almost 100-fold increase within the first week after CAR-T. The same patient also showed marked neurotoxicity and progression of the SNCSL despite continuous surface expression of CD19 on the lymphoma cells and an accumulation of CD4+ central memory-type CAR-T cells in the CNS. Our studies indicate that the local production of chemokine IP-10, possibly through its receptor CXCR3 expressed on our patient's CAR-T, could potentially have mediated the local accumulation of functionally suboptimal anti-tumor T cells. CONCLUSIONS: Our results demonstrate expansion and homing of CAR-T cells into the CNS in SNCSL patients. Local production of chemokines such as IP-10 may support CNS infiltration by CAR-T cells but also carry the potential of amplifying local toxicity. Future studies investigating numbers, phenotype, and function of CAR-T in the different body compartments of SNSCL patients receiving CAR-T will help to improve local delivery of "fit" and highly tumor-reactive CAR-T with low off-target reactivity into the CNS.

Bridging therapy with axicabtagene ciloleucel for large B-cell lymphoma: results from the US Lymphoma CAR-T Consortium.

ABSTRACT: During the manufacturing period of autologous chimeric antigen receptor (CAR) T-cell therapy, patients may experience a decline in their condition due to cancer progression. In this study, we investigated the impact of bridging therapy (BT) on the outcome of patients with relapsed/refractory large B-cell lymphoma who received antilymphoma treatment between leukapheresis and axicabtagene ciloleucel (axi-cel) infusion. We conducted our analysis using data from the multicenter US Lymphoma CAR-T Consortium, with a median follow-up of 33 months (range, 4.3-42.1). Out of the 298 patients who underwent leukapheresis, 275 patients received axi-cel. A total 52% of patients (n = 143) who received BT had a higher baseline risk profile than patients who did not receive BT, and these patients, as a group, had inferior outcomes compared with those who did not receive BT. However, after propensity score matching between the 2 groups, there were no statistically significant differences in overall response rate (77% vs 87%; P = .13), complete response rate (58% vs 70%; P = .1), progression-free survival (hazard ratio [HR], 1.25; P = .23), and overall survival (HR, 1.39; P=.09) between the BT group and the no-BT group, respectively. Analyzing the effects of BT in the whole cohort that underwent leukapheresis regardless of receiving axi-cel (intention-to-treat analysis) showed similar results. Radiation BT resulted in outcomes similar to those observed with nonradiation BT. Our findings suggest that BT may be safe without a significant impact on long-term survival for patients who require disease stabilization during the manufacturing period. Moreover, our results suggest that there is no clear advantage to using radiation-based BT over nonradiation-based BT.

Imaging Biomarkers to Predict Outcomes in Patients With Large B-Cell Lymphoma With a Day 28 Partial Response by 18F-FDG PET/CT Imaging Following CAR-T Therapy.

BACKGROUND: CD19 directed CAR-T therapy for Large B-cell lymphoma (LBCL) has shown great therapeutic response in patients with relapsed/refractory disease with response rates of 60-80%. However, in patients with a partial response (PR) on initial day 28 post CAR-T therapy imaging, clinical uncertainty remains as half of these patients will ultimately have relapsed disease.   PATIENTS: In 24 patients receiving CD19 directed CAR-T therapy for relapsed/refractory LBCL achieving a PR on day 28, we utilize imaging biomarkers by 18F-FDG PET/CT imaging at pre CAR-T therapy baseline and day 28 to determine factors that may predict best overall response (B-OR), progression free survival (PFS), and overall survival (OS).   METHODS: Out of 75 patients receiving CAR-T therapy at a single institution, we retrospectively identified and reviewed 25 (33%) as achieving a PR on day 28. PR was defined using the 2014 Lugano classification system. All patients received standard of care CD19 directed CAR-T therapy with axicabtagene ciloleucel. Two independent nuclear medicine physicians measured baseline (pre-CAR-T therapy) and day 28 PET/CT SUVmax, SUVmean and TMV (cm3) of each lesion (node, organ or marrow uptake, if any) using ROVER software. All statistical tests were two-sided and conducted at the 0.05 level of significance. R version 1.3.1099 (R-studio) was used for statistical modeling.   CONCLUSION: We demonstrate that a higher day 28 SUVmax was significantly higher in those with a B-OR of PR and in our modeling, a lower day 28 SUVmax may predict favorable PFS and OS. Additionally, lower TMV, both at baseline and day 28, may also be predictive of longer PFS and OS, while lower TLG at baseline, but not day 28 is significantly associated with a B-OR of CR. While further study is warranted, these imaging biomarkers may allow for early identification of those with a day 28 PR at highest risk for relapse leading to early intervention to improve long term outcomes.

Randomized Phase II Trial of Dendritic Cell/Myeloma Fusion Vaccine with Lenalidomide Maintenance after Upfront Autologous Hematopoietic Cell Transplantation for Multiple Myeloma: BMT CTN 1401.

PURPOSE: Vaccination with dendritic cell (DC)/multiple myeloma (MM) fusions has been shown to induce the expansion of circulating multiple myeloma-reactive lymphocytes and consolidation of clinical response following autologous hematopoietic cell transplant (auto-HCT). PATIENTS AND METHODS: In this randomized phase II trial (NCT02728102), we assessed the effect of DC/MM fusion vaccination, GM-CSF, and lenalidomide maintenance as compared with control arms of GM-CSF and lenalidomide or lenalidomide maintenance alone on clinical response rates and induction of multiple myeloma-specific immunity at 1-year posttransplant. RESULTS: The study enrolled 203 patients, with 140 randomized posttransplantation. Vaccine production was successful in 63 of 68 patients. At 1 year, rates of CR were 52.9% (vaccine) and 50% (control; P = 0.37, 80% CI 44.5%, 61.3%, and 41.6%, 58.4%, respectively), and rates of VGPR or better were 85.3% (vaccine) and 77.8% (control; P = 0.2). Conversion to CR at 1 year was 34.8% (vaccine) and 27.3% (control; P = 0.4). Vaccination induced a statistically significant expansion of multiple myeloma-reactive T cells at 1 year compared with before vaccination (P = 0.024) and in contrast to the nonvaccine arm (P = 0.026). Single-cell transcriptomics revealed clonotypic expansion of activated CD8 cells and shared dominant clonotypes between patients at 1-year posttransplant. CONCLUSIONS: DC/MM fusion vaccination with lenalidomide did not result in a statistically significant increase in CR rates at 1 year posttransplant but was associated with a significant increase in circulating multiple myeloma-reactive lymphocytes indicative of tumor-specific immunity. Site-specific production of a personalized cell therapy with centralized product characterization was effectively accomplished in the context of a multicenter cooperative group study. See related commentary by Qazilbash and Kwak, p. 4703.

Survival with Axicabtagene Ciloleucel in Large B-Cell Lymphoma.

BACKGROUND: In an analysis of the primary outcome of this phase 3 trial, patients with early relapsed or refractory large B-cell lymphoma who received axicabtagene ciloleucel (axi-cel), an autologous anti-CD19 chimeric antigen receptor T-cell therapy, as second-line treatment had significantly longer event-free survival than those who received standard care. Data were needed on longer-term outcomes. METHODS: In this trial, we randomly assigned patients with early relapsed or refractory large B-cell lymphoma in a 1:1 ratio to receive either axi-cel or standard care (two to three cycles of chemoimmunotherapy followed by high-dose chemotherapy with autologous stem-cell transplantation in patients who had a response). The primary outcome was event-free survival, and key secondary outcomes were response and overall survival. Here, we report the results of the prespecified overall survival analysis at 5 years after the first patient underwent randomization. RESULTS: A total of 359 patients underwent randomization to receive axi-cel (180 patients) or standard care (179 patients). At a median follow-up of 47.2 months, death had been reported in 82 patients in the axi-cel group and in 95 patients in the standard-care group. The median overall survival was not reached in the axi-cel group and was 31.1 months in the standard-care group; the estimated 4-year overall survival was 54.6% and 46.0%, respectively (hazard ratio for death, 0.73; 95% confidence interval [CI], 0.54 to 0.98; P = 0.03 by stratified two-sided log-rank test). This increased survival with axi-cel was observed in the intention-to-treat population, which included 74% of patients with primary refractory disease and other high-risk features. The median investigator-assessed progression-free survival was 14.7 months in the axi-cel group and 3.7 months in the standard-care group, with estimated 4-year percentages of 41.8% and 24.4%, respectively (hazard ratio, 0.51; 95% CI, 0.38 to 0.67). No new treatment-related deaths had occurred since the primary analysis of event-free survival. CONCLUSIONS: At a median follow-up of 47.2 months, axi-cel as second-line treatment for patients with early relapsed or refractory large B-cell lymphoma resulted in significantly longer overall survival than standard care. (Funded by Kite; ZUMA-7 ClinicalTrials.gov number, NCT03391466.).

Chimeric antigen receptor (CAR) T cells for the treatment of a kidney transplant patient with post-transplant lymphoproliferative disorder (PTLD).

Post-transplant lymphoproliferative disorder (PTLD) is a potentially fatal complication following kidney transplantation, and there is a critical and unmet need for PTLD treatments associated with more pronounced and durable responses. To date, reports on the use of CD19-targeted chimeric antigen receptor (CAR) T (CAR-T) cells in patients after solid organ transplant (SOT) have been anecdotal, clinical presentations and outcomes have been heterogenous, and a longitudinal analysis of CAR-T cell expansion and persistence in PTLD patients has not been reported. Our report describes a patient with a history of renal transplant who received CD19-directed CAR-T cell therapy for the treatment of refractory PTLD, diffuse large B cell lymphoma (DLBCL)-type. We show that even with the background of prolonged immunosuppression for SOT, it is possible to generate autologous CAR-T products capable of expansion and persistence in vivo, without evidence of excess T-cell exhaustion. Our data indicate that CAR-T cells generated from a SOT recipient with PTLD can yield deep remissions without increased toxicity or renal allograft dysfunction. Future clinical studies should build on these findings to investigate CAR-T therapy, including longitudinal monitoring of CAR-T phenotype and function, for PTLD in SOT recipients.

Safety and Efficacy of Axicabtagene Ciloleucel versus Standard of Care in Patients 65 Years of Age or Older with Relapsed/Refractory Large B-Cell Lymphoma.

PURPOSE: Older patients with relapsed/refractory (R/R) large B-cell lymphoma (LBCL) may be considered ineligible for curative-intent therapy including high-dose chemotherapy with autologous stem-cell transplantation (HDT-ASCT). Here, we report outcomes of a preplanned subgroup analysis of patients ≥65 years in ZUMA-7. PATIENTS AND METHODS: Patients with LBCL refractory to or relapsed ≤12 months after first-line chemoimmunotherapy were randomized 1:1 to axicabtagene ciloleucel [axi-cel; autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy] or standard of care (SOC; 2-3 cycles of chemoimmunotherapy followed by HDT-ASCT). The primary endpoint was event-free survival (EFS). Secondary endpoints included safety and patient-reported outcomes (PROs). RESULTS: Fifty-one and 58 patients aged ≥65 years were randomized to axi-cel and SOC, respectively. Median EFS was greater with axi-cel versus SOC (21.5 vs. 2.5 months; median follow-up: 24.3 months; HR, 0.276; descriptive P < 0.0001). Objective response rate was higher with axi-cel versus SOC (88% vs. 52%; OR, 8.81; descriptive P < 0.0001; complete response rate: 75% vs. 33%). Grade ≥3 adverse events occurred in 94% of axi-cel and 82% of SOC patients. No grade 5 cytokine release syndrome or neurologic events occurred. In the quality-of-life analysis, the mean change in PRO scores from baseline at days 100 and 150 favored axi-cel for EORTC QLQ-C30 Global Health, Physical Functioning, and EQ-5D-5L visual analog scale (descriptive P < 0.05). CAR T-cell expansion and baseline serum inflammatory profile were comparable in patients ≥65 and <65 years. CONCLUSIONS: Axi-cel is an effective second-line curative-intent therapy with a manageable safety profile and improved PROs for patients ≥65 years with R/R LBCL.

Brexucabtagene Autoleucel for Relapsed or Refractory Mantle Cell Lymphoma in Standard-of-Care Practice: Results From the US Lymphoma CAR T Consortium.

PURPOSE: Brexucabtagene autoleucel (brexu-cel) is an autologous CD19-directed chimeric antigen receptor (CAR) T-cell therapy approved for relapsed/refractory mantle cell lymphoma (MCL). This therapy was approved on the basis of the single-arm phase II ZUMA-2 trial, which showed best overall and complete response rates of 91% and 68%, respectively. We report clinical outcomes with brexu-cel in the standard-of-care setting for the approved indication. PATIENTS AND METHODS: Patients who underwent leukapheresis between August 1, 2020 and December 31, 2021, at 16 US institutions, with an intent to manufacture commercial brexu-cel for relapsed/refractory MCL, were included. Patient data were collected for analyses of responses, outcomes, and toxicities as per standard guidelines. RESULTS: Of 189 patients who underwent leukapheresis, 168 (89%) received brexu-cel infusion. Of leukapheresed patients, 79% would not have met ZUMA-2 eligibility criteria. Best overall and complete response rates were 90% and 82%, respectively. At a median follow-up of 14.3 months after infusion, the estimates for 6- and 12-month progression-free survival (PFS) were 69% (95% CI, 61 to 75) and 59% (95% CI, 51 to 66), respectively. The nonrelapse mortality was 9.1% at 1 year, primarily because of infections. Grade 3 or higher cytokine release syndrome and neurotoxicity occurred in 8% and 32%, respectively. In univariable analysis, high-risk simplified MCL international prognostic index, high Ki-67, TP53 aberration, complex karyotype, and blastoid/pleomorphic variant were associated with shorter PFS after brexu-cel infusion. Patients with recent bendamustine exposure (within 24 months before leukapheresis) had shorter PFS and overall survival after leukapheresis in intention-to-treat univariable analysis. CONCLUSION: In the standard-of-care setting, the efficacy and toxicity of brexu-cel were consistent with those reported in the ZUMA-2 trial. Tumor-intrinsic features of MCL, and possibly recent bendamustine exposure, may be associated with inferior efficacy outcomes.

Outcomes of Busulfan, Fludarabine, and 400 cGy Total Body Irradiation Compared With Busulfan and Fludarabine Reduced-Intensity Conditioning Regimens for Allogeneic Stem Cell Transplantation in Adult Patients With Hematologic Diseases: A Single-Center Experience.

BACKGROUND: Reduced intensity conditioning (RIC) regimens decrease the risk for nonrelapse mortality (NRM) in adult patients undergoing allogeneic hematopoietic stem cell transplantation for hematologic malignancies but increase the risk for relapse. The aim of this study was to compare the outcomes of fludarabine-total body irradiation (TBI) with fludarabine among patients with hematologic diseases. PATIENTS AND METHODS: This retrospective study of 137 patients with different hematologic malignancies compared the outcomes of 63 patients who received a conventional RIC regimen with 2 days of IV busulfan (3.2 mg/kg/d × 2 days) and fludarabine with 74 patients who received the same regimen plus 400 cGy of fludarabine and busulfan (FB)-TBI divided in 2 doses over 1 day (200 cGy BID). Median follow-up was 4.62 years. RESULTS: The donors were either HLA-matched siblings (36%) or HLA-matched unrelated donors (64%). The FB-TBI showed trends toward improvement in progression-free survival (PFS) and overall survival (OS) over FB (5-year PFS rates 50% vs 34%, P = .06, and 5-year OS rate 53% vs 39%, P = .13). Acute graft-vs-host disease (aGVHD), relapse, and NRM were similar between the 2 groups. The 5-year cumulative incidence of chronic GVHD (cGVHD) was lower in the FB-TBI group compared with the FB group (29% vs 52%, P = .003). Multivariable analysis revealed that grade III-IV aGVHD was the only independent risk factor for worse OS (P = .001) in both groups. A high disease risk index was possibly associated with inferior OS (P = .07) in both groups. CONCLUSIONS: The FB-TBI is a safe and effective intensified RIC regimen for adult patients with hematologic malignancies. It predicted a lower risk for cGVHD and showed possibly improved PFS and OS compared with FB.

Ocular adverse events associated with chimeric antigen receptor T-cell therapy: a case series and review.

BACKGROUND/AIMS: Chimeric antigen receptor T-cell (CAR T) therapy has been shown to improve the remission rate and survival for patients with refractory haematological malignancies. The aim of this study is to describe ocular adverse effects associated with CAR T therapy in patients with haematological malignancies. METHODS: This is a retrospective, single-institution, case series. Patients aged 18 years or older who received standard of care CAR T therapy for relapsed/refractory large B-cell lymphoma with a documented ophthalmic evaluation were included. The primary outcome was clinician ophthalmic examination findings. RESULTS: A total of 66 patients received CAR T-cell therapy from February 2018 to October 2019 with 11 receiving an ophthalmic examination. Eleven patients (n=22 eyes) who received CAR T-cell therapy were included in review. The median time from CAR T-cell infusion date to ocular examination was 57.5 days. The median patient age at the time of examination was 60.5 years. Ten patients had subjective symptoms prompting ophthalmic examination. Two patients reported floaters and photopsias. One patient had worsening ocular graft-versus-host disease. Two patients were identified with possible reactivation of viral infections, including herpes zoster ophthalmicus and regressing acute retinal necrosis. CONCLUSIONS: The increasing use of CAR T therapy for malignancies underscores the importance of ophthalmologists and oncologists understanding the potential toxicities associated with its use, particularly ocular toxicities and when to refer for an ophthalmic examination.

Safety and efficacy of letetresgene autoleucel alone or with pembrolizumab for relapsed/refractory multiple myeloma.

This pilot study assessed the safety and efficacy of letetresgene autoleucel (lete-cel; GSK3377794), a genetically modified autologous T-cell therapy targeting New York esophageal squamous cell carcinoma-1 (NY-ESO-1)/L antigen family member 1 isoform A (LAGE-1a)-positive myeloma cells, alone or in combination with pembrolizumab in patients with relapsed/refractory multiple myeloma. Eligible patients expressed NY-ESO-1 and/or LAGE-1a and either HLA-A∗02:01, ∗02:05, or ∗02:06. Patients received lete-cel single infusion alone (arm 1) or with pembrolizumab (arm 2). 127 patients were screened, and 6 patients (3 per arm) were enrolled; patients in arm 1 and 2 received lete-cel alone, or with pembrolizumab, respectively. All patients exhibited grade 3/4 cytopenias, which resolved or improved to grade 1. One patient (arm 1) had grade 3/4 lete-cel-related adverse events (AEs); 2 patients (arm 2) had grade 3/4 AEs related to lete-cel and lymphodepletion. Three patients with grade 1/2 cytokine release syndrome (CRS) exhibited elevated post-lete-cel interleukin-6 levels versus those without CRS. Pooled overall response rate was 50% including 1 patient each with confirmed clinical response, very good clinical response, and partial response, and progression-free survival ranged from 1.3 to 5.2 months. Responders (arm 1: n = 1; arm 2: n = 2) had a time-to-response of 3 weeks, duration of response of 2.1 months. Two responders, but no nonresponders, exhibited elevated cytokine levels after lete-cel infusion. Lete-cel had a manageable safety profile and demonstrated clear but transient antitumor activity in patients with relapsed/refractory multiple myeloma. This trial was registered at www.clinicaltrials.gov as #NCT03168438.