Five-Year Follow-Up of Standard-of-Care Axicabtagene Ciloleucel for Large B-Cell Lymphoma: Results From the US Lymphoma CAR T Consortium

PURPOSE

Axicabtagene ciloleucel (axi-cel) is an autologous CD19 chimeric antigen receptor (CAR) T-cell therapy that is approved for the treatment of relapsed or refractory large B-cell lymphoma. Little is known about the long-term survivorship after CAR T-cell therapy.

METHODS

We previously reported the results of 298 patients who were leukapheresed with the intent to receive standard-of-care axi-cel (n = 275 infused) after two or more previous lines of therapy at a median follow-up of 12.9 months. Here, we report extended follow-up of this cohort to a median of 58 months, with a focus on late survivorship events.

RESULTS

Among axi-cel-infused patients, progression-free survival at 5 years was 29% and overall survival (OS) at 5 years was 40%. The 5-year lymphoma-specific survival was 53% with infrequent late relapses. However, the 5-year nonrelapse mortality (NRM) was 16.2%, with over half of NRM events occurring beyond 2 years. Patients who were 60 years and older had a lower risk of relapse (P = .02), but a higher risk of NRM compared with patients younger than 60 years (NRM odds ratio, 4.5 [95% CI, 2.1 to 10.8]; P < .001). Late NRM was mainly due to infections and subsequent malignant neoplasms (SMNs). In total, SMNs occurred in 24 patients (9%), including therapy-related myeloid neoplasms (n = 15), solid tumors (n = 7), and unrelated lymphoid malignancies (n = 2).

CONCLUSION

In the standard-of-care setting, axi-cel exhibits outcomes consistent with those reported in clinical trials, with sustained, durable responses observed at the 5-year time point. However, late infections and the development of SMN are key survivorship issues that reduce long-term survival after CAR T-cell therapy, particularly in the elderly.

Long-term outcomes of patients with large B-cell lymphoma treated with axicabtagene ciloleucel and prophylactic corticosteroids

ZUMA-1 safety management cohort 6 investigated the impact of prophylactic corticosteroids and earlier corticosteroids and/or tocilizumab on the incidence and severity of cytokine release syndrome (CRS) and neurologic events (NEs) following axicabtagene ciloleucel (axi-cel) in patients with relapsed/refractory large B-cell lymphoma (R/R LBCL). Prior analyses of cohort 6 with limited follow-up demonstrated no Grade ≥3 CRS, a low rate of NEs, and high response rates, without negatively impacting axi-cel pharmacokinetics. Herein, long-term outcomes of cohort 6 (N = 40) are reported (median follow-up, 26.9 months). Since the 1-year analysis (Oluwole, et al. Blood. 2022;138[suppl 1]:2832), no new CRS was reported. Two new NEs occurred in two patients (Grade 2 dementia unrelated to axi-cel; Grade 5 axi-cel-related leukoencephalopathy). Six new infections and eight deaths (five progressive disease; one leukoencephalopathy; two COVID-19) occurred. Objective and complete response rates remained at 95% and 80%, respectively. Median duration of response and progression-free survival were reached at 25.9 and 26.8 months, respectively. Median overall survival has not yet been reached. Eighteen patients (45%) remained in ongoing response at data cutoff. With ≥2 years of follow-up, prophylactic corticosteroids and earlier corticosteroids and/or tocilizumab continued to demonstrate CRS improvement without compromising efficacy outcomes, which remained high and durable.

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.

False-Positive Human Immunodeficiency Virus Nucleic Acid Amplification Test After Chimeric Antigen Receptor T-Cell Therapy With Ciltacabtagene Autoleucel

Chimeric antigen receptor (CAR) T-cell therapy has emerged as a novel therapeutic option for hematologic malignancies. Human immunodeficiency virus (HIV) nucleic acid amplification tests (NAATs) amplifying 5' long terminal repeat and gag genes cross-react with lentiviral vector-based CAR T-cell products. Cross-reactivity between CAR T-cell products and HIV NAATs may lead to false-positive test results.

Allogeneic stem cell transplant outcomes between TBI-containing reduced intensity and myeloablative conditioning regimens for ALL in complete remission

Total-body irradiation (TBI)-based conditioning regimen is preferred in acute lymphoblastic leukemia (ALL). We retrospectively evaluated allogeneic stem cell transplant (alloSCT) outcomes of 86 adult ALL patients in complete remission (CR) who received TBI-containing reduced intensity (RIC) (Flu/Mel/TBI = 31) and myeloablative conditioning (MAC) (VP16/TBI = 47; CY/TBI = 8) between January 2005 and December 2019. All patients received peripheral blood allografts. Patients in the RIC group were older than the MAC group (61 years old versus 36 years, p < .001). Donor was 8/8 HLA-matched in 83% and unrelated in 65% of patients. Three-year survival was 56.04% for RIC and 69.9% for MAC (HR 0.64; p = .19). Propensity score-based multivariable Cox analyses (PSCA) did not demonstrate any difference in grade III-IV acute graft versus host disease (GVHD) (SHR 1.23, p = .91), chronic GVHD (SHR 0.92, p = .88), survival (HR 0.94, p = .92), and relapse-free survival (HR 0.66, p = .47) between both groups, while relapse rate was lower (SHR 0.21, p = .02) for MAC compared to RIC. Our study did not demonstrate any difference in survival for TBI-containing RIC and MAC alloSCT for adult ALL in CR.

Patient-Reported Outcomes in Long-Term Survivors of Autologous Hematopoietic Cell Transplantation in Multiple Myeloma

The overall survival in patients with transplantation-eligible multiple myeloma has tripled over the past 2 decades, leading to a growing population of myeloma survivors. However, there is a paucity of data on health-related quality of life (HRQoL), distress, and health behaviors in long-term myeloma survivors who are in stable remission after autologous hematopoietic cell transplantation (AHCT). In this cross-sectional study using data from 2 randomized controlled trials of survivorship care plans and internet-based self-management intervention in transplantation survivors, the primary objective was to measure HRQoL (using the Short Form-12, version 2.0 [SF-12 v2]), distress (using the Cancer- and Treatment-Related Distress [CTXD] instrument), and health behaviors of myeloma survivors in stable remission after AHCT. A total of 345 patients at a median of 4 years (range, 1.4 to 11 years) post-AHCT were included. The mean SF-12 v2 Physical Component Summary (PCS) score was 45.5 ± 10.5, and the mean Mental Component Summary (MCS) score was 51.3 ± 10.1, compared with US population norms of 50 ± 10 for both (P < .001 and P = .021 for PCS and MCS comparisons, respectively). Notably, neither reached the threshold for a minimal clinically important difference. Approximately one-third of the patients had clinically significant distress based on the CTXD total score, with distress reported by 53% of the patients in the Health Burden domain, by 46% in the Uncertainty domain, by 33% in the Finances domain, by 31% in the Family Strain domain, by 21% in the Identity domain, and by 15% in the Medical Demands domain. Preventive care guidelines were adhered to by 81% of the myeloma survivors; however, adherence to exercise and diet guidelines were relatively low, at 33% and 13%, respectively. Myeloma AHCT survivors in stable remission have no clinically meaningful worsening in physical functioning compared with the general population. Survivorship programs should address ongoing distress due to health burden, uncertainty, and finances in myeloma survivors, along with evidence-based targeted interventions for modifiable health behaviors, such as nutrition and exercise.

Five-year follow-up of ZUMA-1 supports the curative potential of axicabtagene ciloleucel in refractory large B-cell lymphoma

In phase 2 of ZUMA-1, a single-arm, multicenter, registrational trial, axicabtagene ciloleucel (axi-cel) autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy demonstrated durable responses at 2 years in patients with refractory large B-cell lymphoma (LBCL). Here, we assessed outcomes in ZUMA-1 after 5 years of follow-up. Eligible adults received lymphodepleting chemotherapy followed by axi-cel (2 × 106 cells per kg). Investigator-assessed response, survival, safety, and pharmacokinetics were assessed in patients who had received treatment. The objective response rate in these 101 patients was 83% (58% complete response rate); with a median follow-up of 63.1 months, responses were ongoing in 31% of patients at data cutoff. Median overall survival (OS) was 25.8 months, and the estimated 5-year OS rate was 42.6%. Disease-specific survival (excluding deaths unrelated to disease progression) estimated at 5 years was 51.0%. No new serious adverse events or deaths related to axi-cel were observed after additional follow-up. Peripheral blood B cells were detectable in all evaluable patients at 3 years with polyclonal B-cell recovery in 91% of patients. Ongoing responses at 60 months were associated with early CAR T-cell expansion. In conclusion, this 5-year follow-up analysis of ZUMA-1 demonstrates sustained overall and disease-specific survival, with no new safety signals in patients with refractory LBCL. Protracted B-cell aplasia was not required for durable responses. These findings support the curative potential of axi-cel in a subset of patients with aggressive B-cell lymphomas. This trial was registered at ClinicalTrials.gov, as #NCT02348216.

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.

Ciltacabtagene Autoleucel, an Anti-B-cell Maturation Antigen Chimeric Antigen Receptor T-Cell Therapy, for Relapsed/Refractory Multiple Myeloma: CARTITUDE-1 2-Year Follow-Up

PURPOSE

CARTITUDE-1, a phase Ib/II study evaluating the safety and efficacy of ciltacabtagene autoleucel (cilta-cel) in heavily pretreated patients with relapsed/refractory multiple myeloma, yielded early, deep, and durable responses at 12 months. Here, we present updated results 2 years after last patient in (median follow-up [MFU] approximately 28 months), including analyses of high-risk patient subgroups.

METHODS

Eligible patients had relapsed/refractory multiple myeloma, had received ≥ 3 prior lines of therapy or were double refractory to a proteasome inhibitor and immunomodulatory drug and had received prior proteasome inhibitor, immunomodulatory drug, and anti-CD38 therapy. Patients received a single cilta-cel infusion 5-7 days after lymphodepletion. Responses were assessed by an independent review committee.

RESULTS

At a MFU of 27.7 months (N = 97), the overall response rate was 97.9% (95% CI, 92.7 to 99.7); 82.5% (95% CI, 73.4 to 89.4) of patients achieved a stringent complete response. Median duration of response was not estimable. Median progression-free survival (PFS) and overall survival (OS) were not reached; 27-month PFS and OS rates were 54.9% (95% CI, 44.0 to 64.6) and 70.4% (95% CI, 60.1 to 78.6), respectively. Overall response rates were high across all subgroups (95.1%-100%). Duration of response, PFS, and/or OS were shorter in patients with high-risk cytogenetics, International Staging System stage III, high tumor burden, or plasmacytomas. The safety profile was manageable with no new cilta-cel-related cytokine release syndrome and one new case of parkinsonism (day 914 after cilta-cel) since the last report.

CONCLUSION

At approximately 28 months MFU, patients treated with cilta-cel maintained deep and durable responses, observed in both standard and high-risk subgroups. The risk/benefit profile of cilta-cel remained favorable with longer follow-up.

Epidemiology and Predictors of 30-Day Readmission in CAR-T Cell Therapy Recipients

The novel cellular immunotherapy using chimeric antigen receptor (CAR) T cells has transformed the management of several previously incurable hematologic malignancies. Since the first CAR-T cell product was approved by the Food and Drug Administration in 2017, five additional products have been approved for various hematologic malignancies. Although there is now more experience with outpatient administration, CAR-T therapy was initially delivered in an inpatient setting. The unique complications of cytokine release syndrome (CRS) and neurologic side effects (commonly known as immune effector cell-associated neurotoxicity syndrome [ICANS]), along with a higher risk for infection, increase the risk for hospital readmission. Given the recent approval of CAR-T therapy, large-scale epidemiologic data are lacking. The present study aimed to characterize the epidemiology of hospitalizations, readmissions, and factors associated with all-cause 30-day readmission post CAR-T therapy. This retrospective cohort study used the Nationwide Readmissions Database from 2017 to 2019 to identify hospitalizations for CAR-T therapy administration. A descriptive analysis was performed after categorizing these hospitalizations as non-Hodgkin lymphoma, multiple myeloma, or leukemia. The readmission rate was calculated, and etiologies of readmission were identified. A Cox proportional hazards model was used to elucidate factors associated with 30-day readmission. We also estimated the healthcare utilization related to readmissions, including total hospital charges and length of stay. The 2,964 CAR-T therapy-related admissions included 2,176 with a diagnosis of non-Hodgkin lymphoma, 344 with multiple myeloma, and 445 with leukemia. The median length of stay was 15 days. Most CAR-T therapy recipients were male (63.4%), admitted to a teaching hospital (99.2%); 49.3% had private insurance, and 33.2% belonged to the highest-income communities. CAR-T therapy was administered mostly in privately owned (89.5%) large-sized hospitals (74.4%) in large metropolitan regions (91.4%). Median total hospital charges were highest for non-Hodgkin lymphoma, followed by leukemia and multiple myeloma ($945,645 versus $265,034 versus $184,194; P < .001). All-cause mortality during index hospitalization was highest for leukemia at 8.6%, followed by 3.6% for non-Hodgkin lymphoma and 1.4% for multiple myeloma (P < .001). The 30-day all-cause readmission rate was 23.6%, and the median time to readmission was 7 days. The readmission rate was highest for leukemia, followed by non-Hodgkin lymphoma and multiple myeloma (34.2% versus 22.8% versus 15.7%; P < .001). Readmission incurred an additional median total hospital charge of $64,561. During readmission, median length of stay was 5 days, and in-hospital mortality was 4.9%. Top etiologies for readmission were cancer or treatment-related (22%), sepsis or infection (18%), neurologic events (15%), neutropenia or pancytopenia (11%), and fever, hypotension, or hypoxia (8%). On multivariable analysis, non-Hodgkin lymphoma and leukemia (compared with multiple myeloma), transfer to a facility at discharge, chronic renal disease, cerebrovascular disease, and noninvasive ventilation were associated with higher odds of readmission. In contrast, admission to a teaching hospital predicted lower odds of readmission. Almost a quarter of CAR-T therapy recipients are readmitted within the first 30 days resulting in additional economic burden and substantial healthcare utilization.

Impact of Pre-transplant Induction Therapy on Outcomes of Patients Who Undergo Autologous Stem Cell Transplantation for Mantle Cell Lymphoma in First Complete Remission

Mantle cell lymphoma is a rare subtype of non-Hodgkin's lymphoma with poor prognosis and continue to be challenging to treat. The choice of first line induction regimen remains a topic of debate due paucity of clinical trials. We retrospectively evaluated 66 patients diagnosed with mantle cell lymphoma who achieved first complete response after induction chemotherapy followed by autologous stem cell transplant. Treatment groups were divided into low-intensity versus high-intensity regimens. Our data showed the intensity of induction regimen does not impact posttransplant outcomes of mantle cell lymphoma who underwent autologous stem cell transplant in first complete response.

LG. Phase II Trial of Pembrolizumab and Anti-CD3 x Anti-HER2 Bispecific Antibody-Armed Activated T Cells in Metastatic Castration-Resistant Prostate Cancer

PURPOSE

A phase II study was conducted to evaluate the safety and efficacy of the combination of HER2 bispecific antibody (HER2Bi)-armed activated T cells (HER2 BAT) and programmed death 1 inhibitor, pembrolizumab.

PATIENTS AND METHODS

Patients with metastatic castration-resistant prostate cancer (mCRPC) with 0 to 1 performance status and normal liver, kidney, and marrow function, pre- or post-docetaxel chemotherapy were eligible. Primary endpoint was 6-month progression-free survival (PFS). Peripheral blood mononuclear cells were obtained by a single apheresis, shipped to University of Virginia, activated with OKT3 and expanded for 14 days in IL2, harvested, and armed with HER2Bi and cryopreserved. HER2 BATs were infused twice weekly for 4 weeks and pembrolizumab was administered every 21 days for a maximum duration of 6 months starting 1 to 3 weeks prior to HER2 BATs infusion.

RESULTS

Fourteen patients were enrolled with a median age of 69 (range 57-82 years) and median PSA of 143.4 (range 8.2-4210 ng/dL). Two patients had peritoneal metastases, 1 had lymph node (LN) only metastases and 11 had bone metastases of which 7 had bone and LN metastases. All were pretreated with androgen receptor axis targeted agents and 7 (50%) had prior docetaxel chemotherapy. The toxicities were grade1-2 infusion reactions with fever, chills, headaches, nausea and/or myalgias. Primary endpoint of 6 month PFS was achieved in 5 of 14 patients (38.5%; 95% confidence interval, 19.5%-76.5%). Median PFS was 5 months and median survival was 31.6 months.

CONCLUSIONS

The safety and promising efficacy makes this combination worthy of future investigation in mCRPC.

Severity of Cytokine Release Syndrome Influences Outcome After Axicabtagene Ciloleucel for Large B cell Lymphoma: Results from the US Lymphoma CAR-T Consortium

BACKGROUND

The majority of patients with large B-cell lymphoma treated with axicabtagene ciloleucel (axi-cel), an anti-CD19 chimeric antigen receptor (CAR) T-cell therapy, develop cytokine release syndrome (CRS). Whether the lack of development of CRS with axi-cel is associated with inferior lymphoma outcomes is unknown. Additionally, relationship between CRS grade and lymphoma outcome is not well established.

METHODS

The US Lymphoma CAR T Consortium includes seventeen US academic centers that contribute data independently of manufacturers. We analyzed the modified intent-to-treat population of 275 patients receiving axi-cel in two different ways: 1) Two group analysis comparing no CRS with any grade CRS; 2) Three group analysis comparing grade 0 CRS with grade 1 to 2 CRS, and grade 3-5 CRS.

RESULTS

In this large multi-center observational cohort of 275 patients receiving axi-cel, 9% (n = 24) did not develop CRS, 84% (n = 232) developed grade 1-2 CRS, and 7% (n = 19) developed grade 3 to 5 CRS. Patients without CRS, compared with those having any grade CRS, had similar overall response rates (ORR), lower complete response (CR) rates and inferior progression free survival (PFS) with no statistically significant difference in overall survival (OS). Patients experiencing grade 1 to 2 CRS had superior CR rate and PFS, as compared to those without CRS or with grade 3 to 5 CRS. Grade 3 to 5 CRS was associated with a worse OS.

CONCLUSION

Overall, durable responses were seen in patients that did not develop CRS, however grade 1 to 2 CRS was associated with better outcomes while those with grade 3 to 5 experienced the worse outcomes.

Health-Related Quality of Life in Young Adult Survivors of Hematopoietic Cell Transplantation

Young adults (YA), age 18 to 39 years, are at a stage of life that may make them more vulnerable than older adults to impairments in health-related quality of life (HRQOL) during and after hematopoietic cell transplantation (HCT). Health self-efficacy (HSE), the belief that one can implement strategies to produce a desired health outcome, has been associated with health outcomes in oncology research. Little is known about HRQOL or HSE in YA HCT survivors compared with older HCT survivors. Given the age-specific psychosocial challenges facing YA HCT recipients and research on non-transplant YA cancer survivors, we hypothesized that YA survivors would have worse post-HCT HRQOL compared with older adults, and that among YA HCT survivors, higher levels of HSE would be associated with higher levels of HRQOL and lower levels of cancer-related distress. This was a cross-sectional secondary analysis of 2 combined baseline datasets from multicenter studies of HCT survivors approached for participation in clinical trials of survivorship interventions. Participants from 20 transplantation centers in the United States were at 1 to 10 years post-HCT and age ≥18 years at the time of study enrollment, had no evidence of disease relapse/progression or subsequent malignancies, and could read English adequately to consent for and complete assessments. Medical record and patient-reported data were obtained for demographics and HCT-related clinical factors and complications (eg, total body irradiation, chronic graft-versus-host disease [cGVHD]). Participants completed surveys on HRQOL, including the Short-Form [SF]-12, HSE, and Cancer and Treatment Distress (CTXD), which includes 6 subscales and reports an overall mean score. On the SF-12, both the Mental Component Score (MCS) and Physical Component Score (PCS) were calculated. Two cohorts were compared: YAs (age 18 to 39 years at transplantation) and older adults (age ≥40 years at transplantation). Multiple linear regression analyses identified factors associated with HSE, PCS, MCS, and CTXD in YAs. In this analysis of 979 survivors, compared with the older adults, the YA participants had lower median mental health scores (SF-12 MCS: 48.40 versus 50.23; P = .04) and higher cancer-related distress (CTXD: .96 versus .85; P = .04), but better physical health (SF-12 PCS: 48.99 versus 47.18; P = .049). Greater overall cancer-related distress was driven by higher levels of uncertainty, financial concern, and medical demand subscales for YAs compared with older adults. Young adults also had lower HSE (2.93 versus 3.08; P = .0004). In a multivariate model, HSE was strongly associated with age group (P = .0005) after adjusting for multiple other transplantation-related factors. Among YAs, HSE was associated with the SF-12 MCS and PCS and the CTXD, and HSE remained significant after adjusting for other transplantation-related factors. Overall, the YA HCT survivors had lower mental health, increased cancer-related distress, and lower levels of HSE compared with the older adults. Although the direction of these effects cannot be determined with these data, the strong association between HSE and HRQOL among YAs suggests that targeting interventions to improve HSE may have broad impact on health outcomes.

Phase 1b/2 study of ciltacabtagene autoleucel, a BCMA-directed CAR-T cell therapy, in patients with relapsed/refractory multiple myeloma (CARTITUDE-1): Two years post-LPI

8028

Background: Ciltacabtagene autoleucel (cilta-cel), a chimeric antigen receptor T (CAR-T) cell therapy with 2 B-cell maturation antigen (BCMA)–targeting single-domain antibodies, led to early, deep, and durable responses in the phase 1b/2 CARTITUDE-1 study (NCT03548207) in heavily pretreated patients (pts) with relapsed/refractory multiple myeloma (RRMM). At ̃1-year (y) median follow-up (MFU), overall response rate (ORR) was 97%; 67% of pts achieved stringent complete response (sCR). 1-y progression-free survival (PFS) and overall survival (OS) rates were 77% and 89%, respectively (Berdeja 2021). Updated results 2-y post last patient in (LPI) will be presented (̃30-month total MFU). Here, we report CARTITUDE-1 results at 21.7-month MFU. Methods: Eligible pts with RRMM received ≥3 prior lines of therapy (LOT) or were refractory to a proteasome inhibitor (PI) and immunomodulatory drug (IMiD) and had received a PI, IMiD, and anti-CD38 antibody. Bridging therapy was permitted after apheresis. Pts received a single cilta-cel infusion (target dose 0.75×106 CAR+ viable T cells/kg) 5–7 days after lymphodepletion. Primary objectives were to evaluate cilta-cel safety and efficacy. Response was assessed per International Myeloma Working Group criteria by independent review committee and minimal residual disease (MRD) negativity at 10-5 by next-generation sequencing. Results: As of July 22, 2021, 97 pts (59% male; median age 61 y) received cilta-cel. Pts had a median of 6 (range 3–18) prior LOT; 84% were penta-drug exposed, 88% were triple-class refractory, 42% were penta-drug refractory, and 99% were refractory to last LOT. ORR was 97.9% (95% CI 92.7–99.7), 94.9% achieved very good partial response, and 82.5% achieved sCR. Median times to first response, best response, and ≥CR were 1.0, 2.6, and 2.9 months (m), respectively; median duration of response was not reached (NR). Of 61 pts evaluable for MRD, 92% were MRD negative (10-5), sustained for ≥6 m in 44% (27/61) and ≥12 m in 18% (11/61). 2-y PFS was 60.5% (95% CI 48.5–70.4). Median PFS and OS were NR. 2-y PFS rates in pts with sustained MRD negativity for ≥6 m and ≥12 m were 91% and 100%, respectively. There were no new safety signals or new events of CAR-T cell neurotoxicity, movement and neurocognitive treatment-emergent adverse events, or treatment-related deaths since 1-y MFU. 15 second primary malignancies were reported in 11 pts over ̃2-y MFU. Conclusions: At ̃2-y MFU, a single cilta-cel infusion led to deepening and durable responses in heavily pretreated pts with RRMM with a manageable safety profile. Follow-up is ongoing, and landmark 2-y post LPI data (̃8 m additional follow-up; ̃30 m total MFU) will be presented. Further investigations of cilta-cel are ongoing in earlier LOT and outpatient settings across the CARTITUDE program (NCT04133636, NCT04181827, NCT04923893). Clinical trial information: NCT03548207.

Process, resource and success factors associated with chimeric antigen receptor T-cell therapy for multiple myeloma

Background: Chimeric antigen receptor T-cell (CAR-T) therapy represents a new frontier in multiple myeloma. It is important to understand critical success factors (CSFs) that may optimize its use in this therapeutic area. Methods: We estimated the CAR-T process using time-driven activity-based costing. Information was obtained through interviews at four US oncology centers and with payer representatives, and through publicly available data. Results: The CAR-T process comprises 13 steps which take 177 days; it was estimated to include 46 professionals and ten care settings. CSFs included proactive collaboration, streamlined reimbursement and CAR-T administration in alternative settings when possible. Implementing CSFs may reduce episode time and costs by 14.4 and 13.2%, respectively. Conclusion: Our research provides a blueprint for improving efficiencies in CAR-T therapy, thereby increasing its sustainability for multiple myeloma.

Outcomes of Allogeneic Hematopoietic Cell Transplantation in T-cell Prolymphocytic Leukemia: A Contemporary Analysis from the Center for International Blood and Marrow Transplant Research

T cell prolymphocytic leukemia (T-PLL) is a rare, aggressive malignancy with limited treatment options and poor long-term survival. Previous studies of allogeneic hematopoietic cell transplantation (alloHCT) for T-PLL are limited by small numbers, and descriptions of patient and transplantation characteristics and outcomes after alloHCT are sparse. In this study, we evaluated outcomes of alloHCT in patients with T-PLL and attempted to identify predictors of post-transplantation relapse and survival. We conducted an analysis of data using the Center for International Blood and Marrow Transplant Research database on 266 patients with T-PLL who underwent alloHCT between 2008 and 2018. The 4-year rates of overall survival (OS), disease-free survival (DFS), relapse, and treatment-related mortality (TRM) were 30.0% (95% confidence interval [CI], 23.8% to 36.5%), 25.7% (95% CI, 20% to 32%), 41.9% (95% CI, 35.5% to 48.4%), and 32.4% (95% CI, 26.4% to 38.6%), respectively. In multivariable analyses, 3 variables were associated with inferior OS: receipt of a myeloablative conditioning (MAC) regimen (hazard ratio [HR], 2.18; P < .0001), age >60 years (HR, 1.61; P = .0053), and suboptimal performance status, defined by Karnofsky Performance Status (KPS) <90 (HR, 1.53; P = .0073). Receipt of an MAC regimen also was associated with increased TRM (HR, 3.31; P < .0001), an elevated cumulative incidence of grade II-IV acute graft-versus-host disease (HR, 2.94; P = .0011), and inferior DFS (HR, 1.86; P = .0004). Conditioning intensity was not associated with relapse; however, stable disease/progression was correlated with increased risk of relapse (HR, 2.13; P = .0072). Both in vivo T cell depletion (TCD) as part of conditioning and KPS <90 were associated with worse TRM and inferior DFS. Receipt of total body irradiation had no significant effect on OS, DFS, or TRM. Our data show that reduced-intensity conditioning without in vivo TCD (ie, without antithymocyte globulin or alemtuzumab) before alloHCT was associated with long-term DFS in patients with T-PLL who were age ≤60 years or who had a KPS >90 or chemosensitive disease.