Post CAR-T Research Articles

Characterization of second primary malignancies post CAR T-cell therapy: real-world insights from the two global pharmacovigilance databases of FAERS and VigiBase

The FDA's alerts regarding the T-cell lymphoma risk post CAR-T therapy has garnered global attention, yet a comprehensive profile of second primary malignancies (SPMs) following CAR-T treatment is lacking. We extracted adverse event reports of hematological malignancies (HMs) patients with clearly definable SPMs from the FAERS and VigiBase databases (2017-2023). Disproportionality analysis using reporting odds ratio (ROR) and adjusted ROR was performed to assess associations between SPMs and CAR-T therapy. Time-to-onset analysis explored factors affecting SPM manifestation. SPMs post CAR T-cell therapy include HMs and solid tumors. T-cell lymphoma and myelodysplastic syndromes were consistently identified as positive signals across the overall and subgroup analyses. Hematological SPMs showed earlier onset with increasing annual incidence post CAR-T therapy, whereas solid tumors exhibit delayed manifestation. SPMs in CAR-T recipients had significantly earlier onset than non-recipients. Furthermore, age-specific characteristics reveal earlier SPM manifestations in pediatric, adolescent, and young adult populations compared to older populations post CAR-T therapy. The current SPM profile highlights the necessity of long-term safety monitoring for all CAR-T recipients given the observed yearly increase of SPMs. Customizing long-term SPM screening across different age groups may enhance early detection and intervention strategies, ultimately improving patient outcomes in the follow-up of CAR-T recipients. This work was supported by grants from the Natural Science Foundation of Guangdong Province (2018A030313846 and 2021A1515012593), the Science and Technology Planning Project of Guangdong Province (2019A030317020), the National Natural Science Foundation of China (81802257, 81871859, 81772457, 82172750, 82172811, and 82260546), the Guangdong Basic and Applied Basic Research Foundation (Guangdong-Guangzhou Joint Funds) (2022A1515111212), and the Science and Technology Program of Guangzhou (2023A04J1257).

Abstract PR01: EZH2 inhibitors improve CAR-T therapy by enhancing lymphoma B cell immunogenicity and CAR-T cell functions

Abstract Although CAR-T19 therapy is widely used for relapsed/refractory B cell lymphomas, approximately half of patients experience post CAR-T relapse. The mechanisms underlying this resistance remain largely unknown and efforts to overcome this limitation are hindered by the lack of suitable pre-clinical models for study. To address these unmet needs, we generated a novel genetically engineered mouse model with conditional expression of Ezh2Y641F and BCL2 in germinal center (GC) B cells. Ezh2/BCL2 mice developed follicular lymphoma (FL) which histologically and transcriptionally recapitulates human FL. Moreover, we established a cell line derived from an Ezh2/BCL2 mouse that developed transformed FL (tFL). Injection of the cell line named “tFL-P6” in immunocompetent C57BL6 recipients resulted in rapid disease progression that histologically and transcriptionally mimics human tFL. Treatment of tFL-P6 with EZH2 inhibitors (EZH2i) didn’t affect proliferation and viability, however, the number of pretreated cells was significantly reduced when co-cultured with T cells. EZH2i pretreated tFL-P6 displayed extended interaction with T cells, as measured by live imaging. EZH2i reprogrammed tFL-P6 to restore T cell engagement genes such as ICOSL, ICAM1, OX40L, and integrins, as well as cytokines and chemokines involved in T cell recruitment, therefore enhancing immunogenicity. Notably, pretreated tFL-P6 cells were rejected by C57BL6 whereas they developed lethal disease in immunodeficient recipients. Pre-treatment of tFL-P6 as well as human DLBCL and PDX-derived cell lines significantly enhanced CAR-T19 cell killing effects in vitro. Administering CAR-T cells in mice engrafted with EZH2i-pretreated tFL-P6 significantly reduced the tumor burden and prolonged their survival (100% vs 30%, p<0.01). To assess the direct interactions between lymphoma cells and CAR-T cells in vivo, we performed intravital 2-photon imaging of popliteal lymph nodes using dTomato labeled CAR-T cells and GFP+ tFL-P6 cells. Pretreatment of tFL-P6 cells with EZH2i doubled the recruitment of CAR-T cells in the microenvironment and enhanced the duration of contact and surface engagement with CAR-T cells. To explore the impact of EZH2 inhibition on CAR-T cells, we manufactured CAR-T cells from splenic T cells of mice treated with EZH2i or vehicle for 14 days. Prior exposure to EZH2i didn’t affect proliferation and transduction during CAR-T production. Ex vivo assays with those CAR-T cells and tFL-P6 cells showed a superior killing effect and expansion of EZH2i-exposed CAR-T (p<0.001). Mice bearing tFL-P6 lymphomas displayed a longer survival when infused with EZH2i-pretreated CAR-T cells (p=0.06). Pretreatment with EZH2i resulted in an increased memory/effector ratio (p<0.01) and reduction of PD1+CD38+ exhausted CD8CAR-T cells (p<0.001). Overall, EZH2i improved CAR-T therapy by enhancing lymphoma cell immunogenicity and CAR-T cell functions. These results prompted the initiation of a clinical trial to evaluate the safety and efficacy of this combination in R/R B cell lymphomas (NCT05934838). Citation Format: Yusuke Isshiki, Xi Chen, Matt Teater, Ioannis Karagiannidis, Henna Nam, Amy Chadburn, Ari Melnick, Wendy Béguelin. EZH2 inhibitors improve CAR-T therapy by enhancing lymphoma B cell immunogenicity and CAR-T cell functions [abstract]. In: Proceedings of the Fourth AACR International Meeting on Advances in Malignant Lymphoma: Maximizing the Basic-Translational Interface for Clinical Application; 2024 Jun 19-22; Philadelphia, PA. Philadelphia (PA): AACR; Blood Cancer Discov 2024;5(3_Suppl):Abstract nr PR01.

Consolidation with First and Second Allogeneic Transplants in Adults with Relapsed/Refractory B-ALL Following Response to CD19CAR T Cell Therapy

CD19-targeted chimeric antigen receptor T cell (CAR-T) therapy has led to unprecedented rates of complete remission (CR) in children and adults with relapsed/refractory (r/r) B-cell acute lymphoblastic leukemia (B-ALL), yet the majority of adults relapse after initial response. One proposed method to extend the durability of remission in adults following response to CAR-T therapy is consolidation with allogeneic hematopoietic cell transplantation (alloHCT). Considering the limited published data for the utility of post CAR-T therapy consolidative alloHCT in r/r B-ALL, especially data related to patients receiving a second alloHCT, we sought to describe outcomes of patients with r/r B-ALL at our institution who received their first or second alloHCT following response to CAR-T therapy. We performed a retrospective analysis of adult patients with r/r B-ALL who responded to either investigational or standard of care (SOC) CD19-targeted CAR-T therapy and underwent consolidation with alloHCT while in CR without interim therapy. We identified 45 patients, of whom 26 (58%) and 19 (42%) received their first and second alloHCT as consolidation post CAR-T therapy, respectively. The median age was 31 years (range: 19-67) and 31 (69%) patients were Hispanic. Ph-like was the most common genetic subtype and comprised over half of cases (53%; n = 24). The median number of prior therapies pre-transplant was 5 (range: 2-7), and disease status at the time of alloHCT was CR1, CR2 or ≥CR3 in 7 (16%), 22 (49%) and 16 (35%) patients, respectively. The median time from CAR-T therapy until alloHCT was 93 (range: 42-262) days. The conditioning regimen was radiation-based myeloablative (MAC) in 22 (49%) patients. With a median follow-up of 2.47 years (range: 0.13-6.93), 2-year overall survival (OS), relapse free survival (RFS), cumulative incidence of relapse (CIR) and non-relapse mortality (NRM) were 57.3% (95% CI: 0.432-0.760), 56.2% (95% CI: 0.562-0.745), 23.3% (95% CI: 0.13-0.42), and 20.4% (95% CI: 0.109-0.384), respectively. Two-year OS (52% vs. 68%, P = .641), RFS (54% vs. 59%, P = .820), CIR (33.5% vs. 8.5%, P = .104), and NRM (12.5% vs. 32.2%, P = .120) were not significantly different between patients who underwent their first vs. second transplant, respectively. In univariate analysis, only Ph-like genotype was associated with inferior RFS (P = .03). AlloHCT post CAR-T response is associated with a relatively low early mortality rate and encouraging survival results in high-risk adults with r/r B-ALL, extending to the second alloHCT for fit and eligible patients.

Flat dose intravenous immunoglobulin (IVIG) for primary infection prophylaxis after CAR-T for B-cell non-Hodgkin lymphoma (B-NHL).

e19004 Background: Prolonged hypogammaglobulinemia is a common side effect of CD19 chimeric antigen receptor (CAR) T-cell therapy for B-NHL. Average infection rates 1 year (yr) post CAR-T are 44-53% (Kampouri, Tran Infect Dis 2023). Prophylactic IVIG is typically dosed by weight; however, optimal dosing strategy remains unknown. We explored the efficacy of reduced flat IVIG dose on infection rates and non-relapse mortality (NRM) post CAR-T. Methods: B-NHL pts who received commercial CD19 CAR-T therapy from Nov 2017 to Mar 2023 at Vanderbilt Medical Center were included. All pts were on trimethoprim-sulfamethoxazole and valacyclovir for prophylaxis. IVIG at a flat dose of 10 grams was given for IgG < 400 mg/dL. Relevant clinical variables were collected from day 30 to 1 yr. Infections were defined as mild (treated outpatient), moderate (required admission), or severe (required intensive care unit) and by CTCAE v5 criteria. Severe neutropenia was defined as ANC<500 and severe lymphopenia was ALC<500. NRM was defined by death without progression or relapse. Estimated cost of therapy was $140/gram of IVIG based on previously published data. Results: A total of 43 pts (35 large cell lymphoma, 7 mantle cell lymphoma, and 1 follicular lymphoma) with median follow up of 445 days (range 134-2141) were included. Axicabtagene ciloleucel was given to 34 pts (79%), tisagenlecleucel to 2 pts (5%), and brexucabtagene autoleucel to 7 pts (16%). Median age was 58 (range 22-81). Median number of pre CAR-T therapies was 3 (range 1-7). There were 52 total infections with median time to first infection of 165 days (range 31-365). Of all infections, 21 (40%) were viral, 29 (56%) bacterial, and 2 (4%) fungal. There were 31 (60%) mild infections, 19 (36%) moderate, and 2 (4%) severe. Multiple G≥3 infections occurred in 14 pts (33%). At first infection, 4 pts (10%) had severeneutropenia and 13 pts (31%) had severelymphopenia. IVIG was given to 27 pts (63%). Median IgG at D30 was 438 mg/dL (range 143–1099) and 414 mg/dL (range 133–842) at D60. Prolonged IgG≤400 at 6 months occurred in 15 pts (35%). Median IVIG cost using flat dosing was $2800 (range $0-12,600) compared to a median cost of $8,075 (range $0-76,642) if weight-based dosing was utilized. NRM was 9% (4 pts). Of those pts, only 1 had a G≥3 infection during the first-year post CAR-T. Conclusions: We demonstrate comparable infection rates 1 yr post CD19 CAR-T and low NRM with the use of 10g flat IVIG dosing for consecutively treated pts. In addition, only 1 of 4 pts with NRM had severe infection within 1 yr. Notably, 35% of pts had persistent hypogammaglobulinemia at 6 mo and use of a flat dosing schedule provided substantial cost reduction. These findings should be validated in a prospective randomized trial.

Real world outcome of patients with multiple myeloma who received bispecific antibodies after CAR-T therapy.

7520 Background: There are 2 CAR-T products and 3 bispecific antibodies (BsAbs) that are FDA-approved for patients (pts) with relapsed, refractory multiple myeloma (MM). Clinical trials experience to date suggests that clinical response of BsAb is less impacted after CAR-T therapy. We examined the outcome of pts who received BsAb in standard-of-care (SOC) practice at Mayo Clinic Rochester. Methods: Retrospective analysis of MM patients who received FDA-approved BsAb at Mayo Clinic, Rochester between 12/2022- 1/2024. IMWG criteria was used for clinical response. Results: Sixty-two patients received BsAbs: 77% (48/62) received teclistamab, and 23% (14/62) received talquetamab. Median age was 62 years (range: 33-81), 60% (37/62) were males, and 45% (28/62) received prior CAR-T. Patients who had prior CAR-T therapy had more prior lines of therapy compared to those who did not. Overall, ORR to teclistamab was 61%, which is comparable to previous studies and other real-world reports. ORR and ≥CR rates were comparable between patients with and without prior CAR-T (Table). Of the 28 pts who received CAR-T before BsAbs, 61% (17/28) received idecabtagene vicleucel, 10% (3/28) were ciltacabtagene autoleucel, and 29% (8/28) on clinical trial. We then compared outcome of BsAb between pts who had relapsed from CAR-T within 1 year (n=21, median PFS: 8.84 months (range, 1.12, 10.84)) or after 1 year (n=7, median PFS: 16.62 months (range, 13.30, 36.20)). At the time of BsAb infusion, pts with who relapsed < 1 year vs ≥1 year post CAR-T had comparable blood counts, ALC, M-protein and involved FLC levels, CRP, ferritin and LDH. BsAb CR/sCR rate was significantly higher in pts with disease relapse ≥1 year compared to <1 year post CAR-T (57% vs 14%, p=0.02). Conclusions: Irrespective of prior CAR-T exposure, BsAb have clinical activity in SOC practice in pts with MM. Our preliminary data suggest that responses to BsAbs are better in pts with late compared to early relapse post CAR-T. Longer follow-up is needed to understand the duration of response. Larger, multi-center studies with longer follow-up will help identify factors that impact BsAb response post CAR-T.[Table: see text]

BCMA-directed CART therapy in patients with multiple myeloma and CNS involvement.

7519 Background: CART therapy represents a breakthrough in therapy for patients (ptns) with relapsed or refractory (R/R) multiple myeloma (MM). Pts with MM who have CNS involvement are commonly excluded from clinical trials and have limited therapeutic options. We evaluated the safety and efficacy of BCMA-directed CART therapies in ptns with MM and CNS involvement. Methods: 5 US academic medical centers contributed data to this retrospective analysis. 11 ptns with MM with CNS involvement received BCMA-directed CART (7 and 4 pts received ide-cel and cilta-cel, respectively). Results: Eight (72%) ptns were male, 3 (27%) had high-risk (HR) cytogenetics, and 10 (91%) had extramedullary disease (dz). Four (36%) ptns had brain/cranial nerve dz, 1 (9%) had spine dz, and 6 (55%) had both. CNS dz was evident on MRI in 100% of ptns and on CSF in 4 ptns (36%). Five ptns (45%) had ≤60 days between CNS diagnosis and CART therapy, 3 (27%) had >300 days from CNS dz with 2 requiring CNS-directed therapy (CNS-Tx) close to CART during bridging, and 3 (27%) were diagnosed soon after CART infusion. Six (55%) ptns received CNS-Tx as part of bridging; radiotherapy (RT, 2 ptns), RT + intrathecal (IT) chemotherapy (chemo) (2 ptns), IT chemo (1 ptn), and surgery + RT (1 ptn). Five (45%) ptns didn’t receive CNS-Tx as part of bridging for the following reasons; 3 were diagnosed soon post CART and received RT post-infusion, 1 had recent chemo, and 1 was treated for CNS dz 587 days prior to CART and didn’t require CNS-Tx during bridging. Seven ptns (64%) had treated CNS dz at the time of lymphodepleting chemo. Nine (82%) ptns had grade (G) 1/2 CRS and none had G ≥3CRS. Two ptns (18%) had G1 ICANS, 1 (9%) had G3 ICANS, and none had G4 ICANS. Two ptns experienced delayed neurotoxicity post ide-cel, 1 with delayed lethargy that was treated with steroids, and the other with progressive multifocal leukoencephalopathy that was treated with steroids plus pembrolizumab. None had delayed parkinsonian side effects. With a median follow-up of 104 days post-infusion, the best responses achieved were 45% CR/sCR, 18% VGPR, 9% PR, with an overall response (ORR) of 73%. Seven ptns were evaluable for CNS responses by day 90 with a 100% CNS response rate defined by improved imaging findings or clearance of CSF involvement. CNS recurrence occurred in 1 ptn (9%) by day 172 while 5 (45%) had continued systemic response at last assessment. Conclusions: This study suggests that BCMA directed CART therapy in ptns with MM and CNS involvement is safe and feasible. Of the evaluable ptns for CNS response, 100% showed CNS response by day 90. Larger studies with longer follow up are needed to confirm these findings. [Table: see text]

Abstract 4001: Monocyte transcriptome profiles associated with clinical response in patients with B-cell non-Hodgkin’s lymphoma receiving CD19-directed CAR-T therapy

Abstract Background Although CAR T-cell therapy has achieved remarkable response in patients (pts) with B-cell non-Hodgkin’s lymphoma (NHL), 20-30% of pts still have primary refractory disease (PD1), and another 30-40% relapse (PD2). We and others have shown that monocytes can modulate T-cell functions and impact clinical response to chemoimmunotherapy in NHL. Given that monocytes nadir and recovery kinetics differ from lymphocytes post lymphodepletion chemotherapy, we hypothesize that monocyte phenotype at peak CAR-T expansion and in the early month post CAR-T can modulate immune responses. Methods scRNAseq were performed on peripheral blood mononuclear cells of NHL pts prior to lymphodepletion chemotherapy (pre), at peak CAR-T expansion (peak), and one month following CAR-T (M1). Seurat v4.3.0 was used for unsupervised hierarchical clustering analysis. Lugano criteria was used to determine clinical responses which were categorized as CR (complete remission), PD1, or PD2. Results We analyzed 129,981 monocytes from 77 samples of 32 pts (16 CR, 4 PD1, 12 PD2) and 5 healthy controls. Unsupervised hierarchical clustering analysis identified 13 monocyte clusters: 4 classical monocyte (CM) clusters with transcriptome profiles for enriched signaling in IL-6, TGFβ, EMT, and p53; 2 intermediate monocyte (IM) clusters enriched for IL-1 or CD38 signaling; 2 non-classical monocytes (NM), one with increased CD36 expression; 3 monocytic MDSC clusters with enrichment of TGFβ, SIRPα, and HIF1α signaling; and 2 lymphoma-associated monocytes, expressing CD163 or CD169. At Pre and Peak, the distribution of the monocyte clusters was similar in pts with CR, PD2, or PD1, with only a slight decrease in the percent of NM in the PD2 group at Pre and slight increase of CD36 NM in PD1 at Peak. Compared to Pre, all pts had increased percent of CD36 NM and IL-1 IM at Peak. Interestingly, while the distribution of monocyte clusters was similar at Pre and Peak across clinical responses, GSEA showed that monocytes in CR pts, compared to PD1 and PD2, had gene expression enrichment of MYC target V2 pathway at Pre and TGFβ pathway at Peak. At M1, pts in PD1 had increased percent of p53 and TGFβ CM and decreased percent of NM. In contrast, pts with CR had decreased percent of IL-6 CM, p53 CM, TGFβ CM, IL-1 IM and increased percent of NM. Notably, as pts with CR and PD2 may appear similar clinically at M1, pts with PD2, compared to CR, have increased IL-6 CM, IL-1 IM, and decreased NM. In addition, GSEA showed that PD2 pts had increased IFNα response. Our results demonstrate that monocyte phenotype differences at Pre and Peak could be associated with CAR-T clinical response, and that persistent inflammatory monocyte signaling at M1 in pts with clinical response is associated with relapse. These data suggest a role for development of monocyte biomarkers to predict response and therapeutic targeting. Citation Format: Andre de Menezes Silva Corraes, Panwen Wang, Radhika Bansal, Henan Zhang, Zuoyi Shao, Kevin Regan, Eider Moreno Cortes, Arushi Khurana, Nora Bennani, Yucai Wang, Paul Hampel, Jonas Paludo, Patrick Johnston, Hemant Murthy, Madiha Iqbal, Stephen Ansell, Javier Munoz, Allison Rosenthal, Mohamed Kharfan-Dabaja, Januario Castro, Saad Kenderian, Haidong Dong, Ying Li, Yi Lin. Monocyte transcriptome profiles associated with clinical response in patients with B-cell non-Hodgkin’s lymphoma receiving CD19-directed CAR-T therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4001.

Abstract 53: T-cell receptor repertoire changes associated with clinical response in patients with B-cell non-Hodgkin’s lymphoma receiving CD19 CAR-T therapy

Abstract Background: Although CAR T-cell therapy has achieved remarkable response rates in adult patients (pts) with relapsed and refractory B-cell non-Hodgkin’s lymphoma (NHL), 20-30% of pts still have primary refractory disease, and 30-40% of pts relapse, often within 6 months of therapy. Given that durable clinical response can be achieved without CAR T cell persistence, we hypothesized that durable remission is correlated with the expansion of tumor-reactive T-cell receptor (TCR) clones following CAR T-cell infusion. To assess this, we examined the TCR repertoire of adult pts with B-NHL who received CD19 CAR T-cell (axi-cel) therapy to identify correlates of clinical response. Methods: Single-cell (sc) RNA sequencing (seq) and scTCR-seq were performed on peripheral blood mononuclear cells from B-NHL pts before lymphodepletion chemotherapy (pre), at peak CAR-T expansion (peak), and one month following CAR-T (M1). scRNAseq and scTCR-seq data were processed using CellRanger v7.0.1, which were then analyzed using Immunarch (v0.9.0) for TCR clonality and sample diversity. Diversity was assessed using the Gini coefficient to indicate clone size inequality (0 = maximum diversity). TCR diversity and phenotype of expanded and emerged TCR clones post CAR-T were compared across clinical response categories: CR (complete remission for at least 6 months), PD1 (primary refractory), and PD2 (relapsed after partial or complete response). Results: We analyzed 107,035 T cells from 77 serial samples of 32 pts (16 CR, 4 PD1, 12 PD2) and 5 healthy controls. Compared to pts with PD1 and PD2, pts with CR had a larger Gini coefficient for TCR clones at M1 relative to Pre and Peak. The Gini coefficient was the largest for tumor recirculating CD8 T effector memory (Tem) and activated CD8 peripheral memory (Tpm) cells at M1 for pts with CR. Examining the repertoire of emerged and expanded TCR clones at Peak and M1 from Pre, pts with PD2, compared to pts with CR, had a higher percentage of activated CD8 T peripheral memory (Tpm) and T regulatory cells (Treg) among the emerged clones and activated CD8 Tpm among the expanded clones. Patients with PD1, relative to patients with CR, had more proliferating and non-activated CD8 Tpm among the expanded and emerged clones. Conclusion: NHL pts with CR after CAR-T had more robust clonal expansion of T cells, particularly tumor recirculating CD8 Tem and activated CD8 Tpm, compared to pts with relapsed or refractory disease. In contrast, pts with relapsed or refractory disease had an expansion of TCR clones with a larger proportion of CD8 Tpm and Tregs. Endogenous tumor-reactive TCR expansion may help predict favorable clinical response following CAR T-cell therapy. Citation Format: Aiman J. Faruqi, Panwen Wang, Radhika Bansal, Andre De Menezes Silva Corraes, Henan Zhang, Zuoyi Shao, Kevin Regan, Eider Moreno Cortes, Arushi Khurana, Nora Bennani, Yucai Wang, Paul Hampel, Jonas Paludo, Patrick Johnston, Hemant Murthy, Madiha Iqbal, Stephen Ansell, Javier Munoz, Allison Rosenthal, Mohamed Kharfan Dabaja, Januario E. Castro, Saad Kenderian, Haidong Dong, Ying Li, Yi Lin. T-cell receptor repertoire changes associated with clinical response in patients with B-cell non-Hodgkin’s lymphoma receiving CD19 CAR-T therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 53.

The HSP90-MYC-CDK9 network drives therapeutic resistance in mantle cell lymphoma

Brexucabtagene autoleucel CAR-T therapy is highly efficacious in overcoming resistance to Bruton’s tyrosine kinase inhibitors (BTKi) in mantle cell lymphoma. However, many patients relapse post CAR-T therapy with dismal outcomes. To dissect the underlying mechanisms of sequential resistance to BTKi and CAR-T therapy, we performed single-cell RNA sequencing analysis for 66 samples from 25 patients treated with BTKi and/or CAR-T therapy and conducted in-depth bioinformatics™ analysis. Our analysis revealed that MYC activity progressively increased with sequential resistance. HSP90AB1 (Heat shock protein 90 alpha family class B member 1), a MYC target, was identified as early driver of CAR-T resistance. CDK9 (Cyclin-dependent kinase 9), another MYC target, was significantly upregulated in Dual-R samples. Both HSP90AB1 and CDK9 expression were correlated with MYC activity levels. Pharmaceutical co-targeting of HSP90 and CDK9 synergistically diminished MYC activity, leading to potent anti-MCL activity. Collectively, our study revealed that HSP90-MYC-CDK9 network is the primary driving force of therapeutic resistance.

Post CAR-T Peripheral Lymphocytosis and Its Kinetics Are a Potential Biomarker for Response and Immune Mediated Toxicities

Introduction Although expansion of chimeric receptor antibody (CAR)-T cells after infusion has previously been described, overt lymphocytosis with atypical morphology has not been widely reported in multiple myeloma (MM). Here we describe the kinetics of absolute lymphocyte count (ALC), its relationship with immune mediated toxicities, and clinical outcomes. Methods Thirty-nine patients (pts) receiving BCMA CAR-T (25 pts ciltacabtagene autoleucel (cilta-cel) and 14 pts idecabtagene vicleucel (ide-cel)) from two institutions were retrospectively reviewed. Data on baseline characteristics, presence of extramedullary disease (EMD), conditioning regimen, cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), severity of CRS/ICANS (according to American Society of Transplantation and Cellular Therapy (ASTCT) classification), ALC on day -5 through 14, time to best response (TBR), time to first response (TFR), depth of response, and outcomes were collected. Response was evaluated in pts with >3 months of follow up. Peripheral blood flow cytometry was performed in 3 cases at time of highest ALC. ALC data for 84 pts who received CD19 CAR-T (77 pts with axicabtagene ciloleucel and 7 pts with brexucabtagene autoleucel) for non-Hodgkin lymphoma (NHL) were included as a comparison. Maximum ALC (max-ALC) was defined as the highest ALC between day 0 and +15, baseline ALC was defined as the lowest ALC during day 0 through +3, and absolute ALC increase was defined as the difference of max-ALC and baseline ALC. Results Baseline characteristics of the cohort are described in Table A. Pts who received cilta-cel had earlier onset of CRS (median day +6 (IQR 2 - 8) vs +2 (IQR 1 - 2), p = 0.02), had higher max-ALC after CRS (median 1.7 cel/uL (IQR 0.8 - 5.3) vs 0.81 cel/uL (IQR 0.6 - 1.1), p = 0.02), and had a trend towards later max-ALC (median day +12 (IQR 11 - 13) vs +10 (IQR 9 - 13), p = 0.1). Baseline ALC did not differ by BCMA CAR-T product or number of previous lines of therapy. When compared to the NHL cohort, patients who received BCMA CAR-T had higher max-ALC (1.01 cel/uL (IQR 0.6 - 1.9) vs 0.4 cel/uL (IQR 0.2 - 0.7), p < 0.001) and this max-ALC occurred later (median day max-ALC +12 (IQR 10 - 13) vs day +10 (8 - 10), p < 0.01) Figure C. Higher max-ALC and absolute ALC increase were associated with depth of response and occurrence of CRS/ICANS. Pts who had a deeper response (VGPR/CR) had a higher median max-ALC (1.2 cel/uL (IQR 0.77 - 1.81) vs 0.5 cel/uL (IQR 0.2 - 0.7) p < 0.01) and absolute ALC increase (1.2 cel/uL (IQR 0.7 - 1.8) vs 0.6 cel/uL (IQR 0.2 - 0.7) vs, p = 0.01) compared to those with PR or worse Figure B. Similarly, pts who did not progress on follow-up had higher median max-ALC (0.58 cel/uL (IQR 0.4 - 0.8) vs 1.3 cel/uL (IQR 0.9 - 1.9), p < 0.001) and absolute ALC increase (1.3 cel/uL (0.9 - 1.8) vs 0.6 cel/uL (0.5 - 0.8), p < 0.01) compared to progressors. Pts who experienced CRS had a higher absolute ALC increase i(1.05 cel/uL (0.7 - 2.7) vs 0.27 cel/uL (0.2 - 0.5), p = 0.02), and pts who had ICANS had higher max ALC (3.2 cel/uL (0.8 - 6.4) vs 1.01 cel/uL (0.6 - 1.8), p = 0.2). These results were consistent across BCMA CAR-T product, and there were no differences in baseline ALC across CAR-T product, response, disease progression, or number of previous lines. Furthermore, higher max-ALC was associated with higher odds of having VGPR/CR (OR 32.3 (2.23 - 240), p = 0.04) in univariable logistic regression. Flow cytometry data on 3 pts showed expansion of CD8+ T Cells during peak ALC with increase of CD8:CD4 ratio. Multicolor flow cytometry using an antibody BCMA at time of peak ALC showed expansion of CD4+ and CD8+ CAR-T, and further immunophenotypic characterization (differentiation, maturation, exhaustion) is currently being performed. Conclusions Post-CAR-T lymphocytosis was a common event after BCMA CAR-T therapy for MM, which presented a higher max-ALC, and at a later day when compared to CD19 CAR-T for NHL. Furthermore, ALC dynamics differed by BCMA CAR-T product, with cilta-cel exhibiting later CRS with higher max-ALC peaking at a later day when compared to ide-cel. Furthermore, higher max-ALC and absolute ALC increase were associated with deeper response (VGPR/CR) and sustainable response on follow up. Our findings suggest that peripheral lymphocytosis after CAR-T is disease specific (NHL vs MM) and post CAR-T lymphocytosis in peripheral blood is a potential biomarker for clinical outcomes and toxicity.

Evaluation of the Impact of Tocilizumab Use in Recipients of CAR T Cells for Non-Hodgkin Lymphoma

Introduction: CAR T has revolutionized the treatment of patients with relapsed or refractory (R/R) Non-Hodgkin lymphoma (NHL). Treatment of the major toxicity of cytokine release syndrome (CRS) is tocilizumab (toci) and corticosteroids based on the ASTCT grade. Real-world experiences in the United States and Europe have reported a higher rate of tocilizumab use than in pivotal trials; however, the impact of single or multiple administrations on clinical outcomes is not clear. Methods: Patients diagnosed with diffuse (DLBCL), high grade (HGBCL) and primary mediastinal B cell lymphoma (PMBL) treated at our institution with commercial CAR T were retrospectively identified. The association between the number of doses received with best overall response by day 100, PFS, and OS was investigated through a Cox regression model using a 14-day landmark analysis. Late neutropenia was defined as an ANC <1000/mmc for two consecutive counts beyond day 30 post CAR-T infusion and a 30-day landmark analysis was performed in this case. Results: 230 patients with R/R DLBCL (80%), HGBCL (17%) and PMBL (3%) were included in the analysis. Axicabtagene ciloleucel (Axi-cel), tisagenlecleucel (Tisa-cel), and lisocabtagene maraleucel (Liso-cel) were administered in 62%, 29% and 9% of cases, respectively. Median age at time of CAR-T infusion was 65 years (range 20-86), with a male predominance (63%). The median number of prior treatment lines was 3 (range 1-12), and 21% underwent a prior autologous hematopoietic cell transplant. Disease burden prior to CAR-T infusion can be inferred by the following: bridging therapy was deemed necessary in 77% of patients, pre-lymphodepletion LDH was elevated in 40%, and bulky disease with largest mass diameter was > 10 cm in 10%. CRS and ICANS were grade 2 in 107 patients (46%) and 46 patients (20%), respectively. Median time to first administration of toci was 4 days (range 1-16) with patients receiving 0 (51%), 1 (27%), 2 (14%), or 3-4 (8%) doses. Best response by day 100 for the whole cohort was CR in 138 (60%) and PR in 36 (16%) patients. In univariable analysis, factors associated with a lower likelihood of response were the administration of Tisa-cel (p=0.014), bulky disease (p<0.001), administration of bridging therapy (p=0.009), and being refractory to the last treatment line (p=0.006). Number of doses of tocilizumab did not impact the likelihood of response (p=0.72). In a Cox regression model for survival, number of doses of tocilizumab was not associated with worse PFS (p=0.38, Figure 1) or OS (p=0.64), while other known negative predictors of response had impact on survival, such as bulky and refractory disease. By univariable analysis, tocilizumab administration was significantly associated with prolonged neutropenia (p<0.001). The likelihood to observe an ANC<1000/mmc beyond day 30 increased accordingly to the number of doses received (Figure 2). Other factors associated with late neutropenia were bulky disease (P=0.013), need of bridging therapy (p=0.004), and corticosteroids administration (p<0.001). Conclusion: The number of tocilizumab infusions did not impact CAR T efficacy in terms of overall response and long-term survival, a finding that is concordant with other real-world experiences. The cumulative incidence of late neutropenia events was impacted by the number of doses received. We speculate that a severe CRS driven systemic inflammatory response, requiring several tocilizumab and corticosteroids administrations, may hinder the bone marrow function and recovery.

Ultra-Hypofractionated Involved Site Radiation Therapy (ISRT) As Salvage or Bridging Therapy in Aggressive Non-Hodgkin Lymphomas

Introduction: Conventional fractionated radiation treatment (RT) to a total dose of 40-50 Gy in 20-25 fractions is typically recommended in the ‘definitive’ intent treatment of aggressive chemorefractory non-Hodgkin lymphoma. However, during the time of COVID-19, recommendations for hypofractionated courses (5-13 fractions) arose (Yahalom et al Blood 2020) as modern radiation techniques should allow similar total doses to be delivered safely in far fewer fractions. Our aim is to evaluate the outcomes and toxicities of ultra-hypofractionated (</=5 fractions) ‘definitive’ ISRT in aggressive non-Hodgkin lymphomas to see if this may be an acceptable alternate recommendation beyond COVID-19. Methods: We conducted an IRB-approved, retrospective review of all aggressive non-Hodgkin lymphoma patients treated at our institution with ‘definitive’ intent (40-50 Gy EQD2 with an α/β of 10) ultra-hypofractionated ISRT between April 2020 and July 2023. Demographic, disease-specific, and treatment-related variables were collected. Primary outcomes include objective response rate (ORR), defined as complete (CR) or partial response (PR) on post-RT positron emission tomography (PET) scans using the Lugano classification, local failure (LF), and radiation-related toxicity per CTCAE v5. Secondary outcomes include overall disease control and survival. Results: 26 ultra-hypofractionated radiation treatments were identified from 23 unique patients who were treated with ‘definitive’ intent ISRT (39.1% salvage, 30.4% early-salvage post CAR-T, and 30.4% bridging to SCT or CAR-T). The most common dose was 30 Gy in 5 fractions (96%); all patients were treated with IMRT with SBRT-type immobilization and image guidance as clinically indicated. The most common diagnosis was DLBCL (91%). 10/23 (43%) patients were female, the majority (82%) were ECOG 0-1 performance status, and the average age at time of RT was 68.9 years. 39% had all FDG-avid sites at the time of radiation treated. The median follow-up was 8.3 months (range 0.3-27.9 months). 26% of patients had acute radiation related toxicities, which were all grade 1-2 with the most common being fatigue (30%). There were no grade 3-4 toxicities, and no subacute or long-term toxicities. Initial local ORR was 20/21, or 95% (86% CR and 10% PR), while initial overall ORR was 12/21, or 57% (52% CR and 5% PR). At time of last follow up, only 1/24 (4%) of irradiated sites had local failure (2 data points N/A), with a TTLF of 1.5 months. 62% of patients had disease progression, with median time to disease progression of 1.5 months. At time of last follow up, 48% were dead, with a median time to death of 6.6 months. Conclusions: Ultra-hypofractionated ISRT in the ‘definitive’ intent treatment of aggressive non-Hodgkin lymphomas has excellent local tumor control and appears to be safe with minimal acute and subacute toxicities. In addition to patient convenience and cost effectiveness, short-course ISRT allows patients to quickly move on to next-line therapy when indicated. Prospective studies and long-term follow up are needed to further validate this as an alternative radiation treatment option.

The Outcome of Tisagenlecleucel (Tisa-Cel) Vs Axicabtagene Ciloleucel (Axi-Cel) CD-19 CAR-T Cell Therapy in Relapsed/Refractory NHL, Real World Data, Single Institution Experience

ABSTRACT Background: In the Kingdom of Saudi Arabia, non-Hodgkin lymphoma (NHL) reported as 6.1%. The estimated age adjusted incidence is 6/100,000. The more advanced disease stage at presentation reaches up to 40% stage IV. The cure rate with first line of therapy (R-CHOP) reaches up to 70%. The CD 19 chimeric antigen receptor (CAR) T-cell therapy targets CD19-expressing B cells and shows efficacy against B-cell lymphomas. Objective: The registration of CAR-T therapy products at KSA was in 2020 for Tisa-Cel and 2022 for Axi-Cel. The objective is to describe the outcome of the more available CAR-T therapy products in relapsed or refractory NHL. Methods: Retrospective analysis of CAR-T therapy outcome in NHL and compare the outcome of the two products for the same patient's population, using patients' chart electronic file assessment in the tertiary institution treating over 500 new lymphoma per year. Patients: Between November 2020 and May 2023, 44 patients with relapsed or refractory NHL to ≥2 lines of therapy, Follicular lymphoma (FL) relapsed after three lines of therapy counted for four patients treated with Axi-Cel. All patients received an infusion were included in the analysis. Of the 44 patients, 54.5% were male (n=24), the median age was 51 (20-75), and ECOG was 0-3. NHL subtype includes germinal center B-cell (GCB) 52% (n=23) and activated B-cell (ABC) 38.6% (n=17); the disease stage by PET/CT scan was III (47.7%, n=21) and IV (47.7%, n=21). In Axi-Cel group, 9.1% (n=4) received CAR-T as second line for relapse refractory disease or relapse within 12 months of complete remission (CR) after 1 st line therapy. Other patients received at least two lines of therapy prior to CAR-T infusion; 65.9% received ≥ 3 lines of therapy. Seven patients (16%) relapsed after autologous stem cell transplantation (ASCT) have received CAR-T therapy Tica-Cel product (n=6). Four patients (9.1%) have controlled CNS involvement at the infusion time. All patients received lymphodepletion (LD) therapy with fludarabine and cyclophosphamide (Flu/Cy). 25% (n=11) needed bridging chemotherapy therapy before LD, radiation therapy (XRT) bridging was counted for 13 patients (29.5%). The patients' characteristics and disease in Table-1. Results: Overall response rate (ORR), complete responses (CR), partial responses (PR). The respective toxicities include cytokine release syndrome (CRS) and neurologic events namely ICANS. The best ORR was 68.2%; 43.2% of the patients had CR and 25% had PR. The disease progression (DP) was 29.5%. In Axi-Cel group, ORR, CR, PR, and DP was 84.2%, 52.6%, 31.6% and 10.5, respectively. In Tica-Cel group; ORR, CR, PR, and DP was 56%, 36%, 20% and 44%, respectively. The estimated 2 years overall survival was 75% in all patients; 89.5% and 64% in Axi-Cel and Tica-Cel, respectively (p=0.47), Figure1. The estimated overall progressive free survival (PFS) was 61.4% with 73.7% in Axi-Cel group and 52% in Tica-Cel group (p=0.2), Figure2, the best PFS was seen in GCB subtype 65.2% vs 47.1% in ABC, (p= 0.05), Figure4. In FL, PFS was 100%, the patient number is small. PFS was 62.5% in-patient with CRS compared with 50% on non-CRS patient, not statistically significant (p= 0.7), Figure3. The main toxicities post CAR-T cell infusion including cytokines release syndrome (CRS) was 90.9% with 9% grade ≥ 3. In Tica-Cel, grade CRS-IV was 9% while 0% in Axi-Cel. Neurotoxicity (NT)-ICANS was 27% with grade ≥ 3 of 13.6% in both groups (20% in Tica-Cel and 5.6% in Axi-Cel). Tocilizumab was used in 72.7% in all cohorts with higher number of patients in Axi-Cel 17/19 (98.5%). Dexamethasone (Dexa) was used in CRS in 36.4%, in Axi-Cel; 42% of patients received Dexa while 32% in Tica-Cel group. In addition, for treatment of ICANS; Dexa was needed in 31.6% of Axi-Cel patients and 20% in Tica-Cel group. Upon the latest patient's follow-up, two patients (10.5%) in Axi-Cel group and 36% (n=9) in Tica-Cel group died from DP. The outcome of both products is summarized in Table-2. Conclusions: In this single-center retrospective analysis of CAR T-cell therapy in relapsed or refractory NHL or FL in adults, the rates of durable responses were like the real-world data. The best response rate was higher in Axi-Cel group; however, the follow-up duration of disease response is shorter in Axi-Cel group. The toxicity profile is similar in both groups with a bit higher of Grade-III-IV ICANS in Tica-Cel group. Keywords NHL, FL, CAR-T, CRS, ICANS

Single-cell transcriptomic atlas throughout anti-BCMA CAR-T therapy in patients with multiple myeloma.

The emergence of chimeric antigen receptor (CAR)-T therapy targeting B cell maturation antigen (BCMA) has improved the prognosis of patients with multiple myeloma (MM); however, the majority of patients eventually experience relapse. In this study, employing the latest single-cell RNA sequencing technology, we examined 24 bone marrow or peripheral blood samples collected throughout the course of anti-BCMA CAR-T therapy, analyzing a total of 59,725 bone marrow cells and 72,479 peripheral blood cells. Our findings reveal that tumor cells in relapsed patient exhibit higher expression levels of HSP90B1 and HSPA5, and demonstrate significantly enriched pathways regarding endoplasmic reticulum stress and unfolded protein response. In the analysis of T cells, we observed that patient with impaired effector function and increased expression of immune checkpoints in endogenous T cell are more susceptible to relapse. Notably, T cells from both the bone marrow microenvironment and peripheral blood share highly similar biological characteristics. Overall, this study provides a comprehensive atlas of endogenous immune cells, particularly in the relatively long term, after CAR-T therapy. It offers clinical evidence for a deeper understanding of the internal environment post CAR-T treatment and for identifying mechanisms underlying relapse.

Early Predictors of Severe Cytopenia Post CAR-T for Identification of Patients for Potential Stem Cell Collection

Background: Cytopenias are a common complication of and prolonged (beyond month 3 post CAR-T infusion), severe (grade 3 or higher) cytopenias can be difficult to manage. Stem cell boosts have been reported to restore hematopoiesis; however, stem cells would need to be available prior to CAR-T therapy for potential use post CAR-T. Most lymphoma patients and limited number of myeloma patients may have pre-collected stem cells in storage. Identifying patients at high risk for prolonged and severe cytopenia post CAR-T at the time of CAR-T evaluation (baseline), before leukapheresis, can help identify the patients for coordination of stem cell collection during CAR-T manufacturing and increase the likelihood that the collected stem cells would be used. In this study, we aim to identify clinical variables at the time of CAR-T evaluation, prior to leukapheresis, that are associated with severe cytopenias at month 3 post CAR-T infusion and identify patients who could be considered for pre-emptive stem cell collection prior to CAR-T therapy. Methods: We conducted a retrospective analysis of patients with multiple myeloma (MM) and non-Hodgkin lymphoma (NHL) who received CAR-T products at Mayo Clinic from 01/2016 to 06/2022. Patients with progressive disease in the first year post CAR-T were excluded from the analysis. Baseline (at CAR-T evaluation, prior to leukapheresis) variables were compared between those with and without severe cytopenia at month 3 post CAR-T. Severe cytopenias were defined as hemoglobin (Hg) < 8 g/dL, absolute neutrophil count (ANC) < 0.5 x 10 9/L, and/or platelet count (PLT) < 50 x 10 9/L. Statistically significant variables (p<0.05) by analysis were examined for statistical significance in multivariate analysis (MVA). Results: Among the 166 patients who received CAR-T (88 NHL, 78 MM) during the study period, 31 (18.67%) had a severe cytopenia at month . Twenty baseline variables were examined; HGB, PLT, ANC, and c-reactive protein (CRP) We devised a cytopenia risk score using 1 point each for Hg<10 or PLT<100k at baseline, with a range of 0 to 2. Demographics and clinical outcome by cytopenia risk score is shown in Table 1B. A higher percentage of patients with a score of 1 or 2 had a severe cytopenia at month 3 (Figure 1). In particular, there was a . In addition Conclusion: Baseline cytopenias before leukapheresis may identify patients with increased risk for severe cytopenias at month 3 post CAR-T. These patients can have continued slow hematopoietic recovery in the first year. Stem cell collection, if feasible, could be considered before CAR-T to alleviate post-CAR-T severe prolonged cytopenias.

The Effect of Stem Cell Infusion on Immune Effector Cell Associated Hematotoxicity with BCMA CAR T in Multiple Myeloma

Introduction: In recent pivotal clinical trials and real-world studies of patients undergoing BCMA CAR-therapy for multiple myeloma (MM), a significant percentage have exhibited persistent Immune Effector Cell Associated Hematotoxicity (ICAHT). The resulting, sometimes profound and long lasting cytopenias, are associated with increased morbidity, such as high rates of infections and bleeding and complicate further anti-MM therapy once the patient relapses post CAR-T cell therapy. While growth factor support is widely applied in patients with ICAHT, the effects are usually short lived. Consequently, the use of CD34 selected stem cell boost in ICAHT as a more permanent solution has been described, however studies have been limited by small patient numbers and short follow up. Herein, we report on our multi-institutional experience at ICAHT in patients who received autologous BCMA CAR T therapy both in commercial and clinical trial settings. Methods: We included recipients of autologous BCMA CAR T therapy at 2 large academic centers between 2020 and 2023. For this study, neutropenia was defined as an absolute neutrophil count (ANC) of ≤ 1000, thrombocytopenia as platelet counts ≤ 70,000 and anemia as hemoglobin ≤9 g/dL. ICAHT was characterized by the presence of any of these hematological abnormalities. The variables were assessed at 21 days, 3 months, and 6 months post CAR-T infusion. Median follow up time was 23 months. Results : A total of 108 patients received BCMA CAR T therapy, 42 (39%) were treated on a clinical trial, 52 (48%) received commercial Idecabtagene vicleucel and 14/108 (13%) commercial Ciltacabtagene autoleucel. Baseline characteristics of the whole patient cohort are shown in table 1. The median age was 68 (range 57-69) years, with 63/107 (60%) being male. About 11% (n=12) patients were Black. 97/108 (90%) received at least one prior ASCT and the median prior lines of therapy was 5 (range 4-6). At D+21, ICAHT was observed in 68% (n=69/102) of patients, which reduced to 35% (n=30/86) and 27% (n=21/78) at the 3-month and 6-month assessments, respectively. Risk factors for ICAHT were the following: history of a prior ASCT, higher number of prior lines of therapy, a decreased platelet count prior to lymphodepletion and history of ICANS, which interestingly occurred in 11/69 (16%) patients who developed ICAHT but was not seen in those without ICAHT. About 97%(n=67/69) of patients with ICAHT had stem cells in storage and 26% (n=17/69) received a stem cell boost. The median time to stem cell boost following CAR T infusion was 116 (range 49-166) days. The median dose of stem cell infused was 3.91 (range 2.11-5.12) x10 6 CD34/kg cells. Unsurprisingly, patients with ICAHT who received a stem cell boost had significantly worse cytopenias prior to stem cell boost compared to those ICAHT patients without stem cell infusions at 120 days. Hgb was 8.4g/dL vs 10.2g/dL, p=0.02, and mean platelet levels were 30x10 9/L vs 54x10 9/L, p=0.01, compared to ICAHT patients without stem cell support. ANC levels were not significantly different between those two ICAHT groups (1700/mL vs 1500/mL), likely due to a higher use G-CSF support in ICAHT patients who received stem cell support (75% vs 55%, NS). Stem cell infusion significantly improved Hgb levels at 3 and 6 months follow up with an increase to 10.6g/dL, p=0.002, and 10.5g/dl, p=0.02, respectively. Similarly, platelet counts at 3- and 6-months post stem cell boost improved significantly to 131x10 9/L, p=<0.001, and 150x10 9/L, p=<0.001, respectively. ANC levels showed a nonsignificant increase to 2.8/mL and 3.9/mL at 3 and 6 months, yet, G-CSF support was no longer required. We further investigated whether the occurrence of secondary AML/MDS was associated with ICAHT, however these events were rare and developed in only 2 patients, one who had no ICAHT and the other one who had ICAHT without stem cell boost. Conclusion: Nearly one-third of the patients who underwent BCMA CAR T therapy continued to experience ICAHT even at the 6-month post-infusion period. The utilization of a stem cell boost for managing ICAHT lead to significantly improved Hgb and platelet counts at 3 and 6 months follow up with also substantial improvement in ANC without further G-CSF requirements. These results suggest that the use of stem cell infusions in CAR-T cell induced ICAHT can improve cytopenia associated morbidities and facilitate further anti MM therapy post CAR-T relapse.

Healthcare Utilization Outcomes of Outpatient CAR-T Cell Therapy with Remote Patient Monitoring Program

Introduction While chimeric antigen receptor (CAR)-T cell therapy has transformed the management of hematologic malignancies, it requires frequent monitoring for acute toxicities, almost universally achieved through mandatory hospitalizations, therefore utilizing a significant amount of healthcare resources. At Mayo Clinic in Rochester, MN, our standard practice is administering CAR-T cell therapy in the outpatient setting through a multi-disciplinary hospital-based outpatient (HBO) unit and remote patient monitoring (RPM) program. Our CAR-T RPM program consists of in-home, electronic health record-integrated technology to monitor vital signs and neurologic symptoms for 30 days post CAR-T infusion. Here we report the healthcare utilization outcomes of CAR-T patients managed in the outpatient setting enrolled in the RPM program. Methods Patients undergoing FDA-approved CAR-T cell treatment in the outpatient setting and participating in the CAR-T RPM program at Mayo Clinic Rochester were included in this IRB-approved study. Patient characteristics, healthcare utilization metrics, inpatient interventions, and patient satisfaction data regarding the RPM program were reviewed. Length of stay (LOS) includes any hospitalizations for which the admission date falls within the RPM monitoring period (CAR-T cell infusion to day +30), even if the hospitalization continued past day +30. Results A total of 123 patients participated in the CAR-T RPM program and underwent treatment in the outpatient setting. Median age at CAR-T infusion was 63 years (range 22 - 83), and most patients were male (n=78, 63%). Non-Hodgkin lymphoma was the most common diagnosis (n=74, 60%), followed by multiple myeloma (n=47, 38%), ALL (n=1, 1%) and other (n=1, 1%). During the PRM monitoring period, 19 (16%) patients were managed entirely in the outpatient setting. The remaining 104 (84%) patients required at least one hospitalization, with most patients (n=70, 57%) hospitalized only once [26 (21%) patients were hospitalized twice, and 7 (6%) patients were hospitalized 3 times, and 1 (1%) patient hospitalized 4 times during the monitoring period]. When considering the first hospitalization post CAR-T infusion, the median LOS was 6 days (range 2 - 47). When considering all hospitalizations post CAR-T, the median LOS was 8 days (range 2 - 47). Only 7 (6%) patients required an ICU stay, with a mean ICU stay of 0.2 days (standard deviation 0.9). Cytokine release syndrome (CRS) was noted in 92 (75%) of patients at a median of 3 days (range 0 - 18) post CAR-T infusion. All patients with CRS received tocilizumab, at a median of 4 days post CAR-T infusion. Steroids for CRS were administered in 63 (68%) of these patients. Neurotoxicity was reported in 45 (37%) patients at a median of 7 days (range 1 - 19) post CAR-T infusion. During the RPM monitoring period, patients were seen in our HBO unit with a median of 18 outpatient visits (range 4 - 30). Patient survey data, obtained at the end of the RPM monitoring period, were available from 37 patients. The majority of patients felt that the RPM program helped them feel comfortable managing their health at home, were able to reach a team member, and receive an appropriate response promptly. The majority of patients felt comfortable using the RPM equipment and interacting with providers virtually. Overall, 83% of patients were satisfied with the RPM program and 6% were neither satisfied nor dissatisfied. When asked about the reason for disappointment, technical difficulties/issues with the devices were the themes mentioned by the few patients (11%) who were unsatisfied with the RPM program. Conclusion: Despite the complexities and frequent monitoring associated with CAR-T cell therapy, outpatient CAR-T cell treatment is a feasible model of care. As the standard practice at our institution, the CAR-T RPM program was part of the management of nearly all patients undergoing an FDA-approved CAR-T product in the outpatient setting. RPM in the acute setting post CAR-T infusion is a well-received practice initiative by the majority of patients, including a high level of comfort utilizing the RPM equipment and virtual interaction with the RPM providers.

Odronextamab Demonstrates Durable Complete Responses in Patients with Diffuse Large B-Cell Lymphoma (DLBCL) Progressing after CAR-T Therapy: Outcomes from the ELM-1 Study

Background Chimeric antigen receptor (CAR) T-cell therapies have recently been established as an important option for the management of relapsed/refractory (R/R) DLBCL. However, real-world studies suggest that approximately half of all patients (pts) receiving commercial CAR-T therapies will relapse within 6 months. These pts have a poor prognosis, with estimated overall survival (OS) of only 5 months, indicating a significant unmet need. Odronextamab is a novel, off-the-shelf, CD20×CD3 bispecific antibody that has demonstrated activity in both R/R follicular lymphoma and R/R DLBCL. We have previously reported encouraging results with odronextamab from the Phase 1 ELM-1 study (NCT02290951) in pts with R/R DLBCL post CAR-T therapy (Bannerji R, et al. Lancet Haematol. 2022). These results were consistent with the antitumor activity seen in pts with R/R DLBCL from the Phase 2 ELM-2 study (Kim WS, et al. ASH 2022). Here, we present an updated analysis of outcomes in a prespecified cohort of post CAR-T patients from ELM-1. Methods Intravenous odronextamab was administered weekly in 21-day cycles during Cycles (C) 1-4. Revisions to the step-up regimen were reported previously (Bannerji R, et al. Lancet Haematol. 2022). Odronextamab was administered with steroid prophylaxis and step-up doses of 0.7/4/20 mg during C1 to mitigate the risk of cytokine release syndrome (CRS), followed by 160 mg on Days (D) 1, 8, and 15 of C2-4. After C4, odronextamab maintenance treatment continued at 320 mg every 2 weeks until disease progression or unacceptable toxicity. Those pts who achieved a complete response (CR) that was durable for ≥9 months transitioned to dosing with 320 mg every 4 weeks. The primary endpoint was objective response rate (ORR), assessed by independent central review (ICR) according to the Lugano classification. Key secondary endpoints included duration of response (DoR), progression-free survival (PFS), and OS. Immune biomarker assessment was an exploratory endpoint. Results As of Dec 20, 2022, 46 pts were treated (safety-evaluable), with 44 pts evaluable for efficacy. For safety-evaluable pts, median age was 63 years (range 27-82), 67% male, 74% Ann Arbor stage III-IV, and 72% were refractory to CAR-T therapy administered in any prior line. 44 pts were evaluable for efficacy after 4.9 months median duration of follow-up. The ORR and CR rate by ICR were 48% (21/44) and 30% (13/44), respectively. Responses were durable, and both median DoR and median duration of CR were not reached. The probability of maintaining a response for 12 months was 62% and the probability of maintaining a CR for 9 months was 86%.A responder analysis of the subgroup of pts who achieved a CR will be presented. The CAR-T treated pts with DLBCL who were evaluable for biomarker analysis (n=10) had lower T-cell counts at baseline compared with CAR-T naive DLBCL pts (n=41 comparable pts who received odronextamab in ELM-2), yet the fold-change of T-cell expansion at C4D15 was greater in CAR-T treated pts versus CAR-T naive pts. T-cell dynamics, such as changes in activation, exhaustion, and memory subsets, will be presented. Safety was generally consistent with that previously reported. Six (13%) pts permanently discontinued odronextamab due to a treatment-emergent AE (device-related infection, pneumonia, dysphagia, gait disturbance, leukemia, and encephalopathy [n=1 each]). The most common treatment-emergent AE was CRS (any grade, 52%). The highest grade of CRS reported was Grade 2, and low-grade CRS events occurred in 46% of pts with the 0.7/4/20 mg step-up regimen. No cases of ICANS were reported in pts with the 0.7/4/20 mg regimen. Grade ≥3 infections occurred in 10 (22%) pts, with no Grade 5 events. No cases of tumor flare were reported. Conclusions Odronextamab monotherapy demonstrates encouraging antitumor activity in heavily pretreated pts who have progressed after CAR-T therapy, with a generally manageable safety profile. Durable CRs were achieved in this difficult-to-treat setting. These data support the potential role of odronextamab in the treatment paradigm for R/R DLBCL. Further studies to evaluate the optimal sequencing and combinations of odronextamab with CAR-T therapy are warranted.

Chimeric Antigen Receptor T-Cell (CAR-T) Therapy in Secondary Central Nervous System Large B-Cell Lymphoma (SCNSL): A Multicenter Retrospective Analysis

Introduction Secondary central nervous system (CNS) involvement develops in 2-10% of large B-cell lymphoma (LBCL) cases. Current treatment approaches for relapsed or refractory CNS disease generally do not provide durable responses. Limited data suggest efficacy and feasibility of CAR-T therapy in SCNSL. We report here the largest multicenter retrospective analysis of the safety and efficacy of CD19-directed CAR-T therapy in SCNSL patients. Methods This study included SCNSL patients who received commercial CD19-directed CAR-T therapy at 9 academic institutions in the United States between 2016 and 2022. SCNSL was defined as history of parenchymal and/or leptomeningeal/cerebrospinal fluid (CSF) involvement by lymphoma at any time prior to receiving CAR-T therapy. Systemic response was assessed using the Lugano criteria while CNS response was assessed as per International PCNSL Collaborative Group criteria. Kaplan-Meier curves were generated for progression-free survival (PFS) and overall survival (OS) for entire cohort, as well as subsets of patients with and without active CNS disease at the time of CAR-T infusion. Results Ninety patients were included in the analysis, with baseline characteristics shown in Table 1. CAR-T products utilized include axicabtagene ciloleucel (n= 38, 42%), tisagenlecleucel (n=37, 41%) and lisocabtagene maraleucel (n= 15, 14%). Fludarabine/cyclophosphamide was used as lymphodepletion in 84 patients (93%). 28 patients received CNS directed radiation therapy (RT) prior to CAR-T infusion (31%) within a median time of 28.5 days (range 5 - 906) from last day of RT. Amongst all patients at the time of CAR-T infusion 82 (91.1%) had active CNS and/or systemic involvement while 8 (8.9%) had no evidence of disease; 68 (75.5%) had active CNS involvement while 22 (24.5%) had a prior history of CNS involvement but no active at the time of CAR-T infusion. ( Table 1) Median follow up all patients was 0.5 year (range 0.01 - 4.7). 71 patients (79%) developed cytokine release syndrome (CRS; median time to onset 3 days) with 3.3% patients developing Grade 3-4. Immune effector cell-associated neurotoxicity syndrome (ICANS; median time to onset 5 days) was reported in 55 patients (61%), with 28.8% developing Grade 3-4. No patients died due to CRS or ICANS. At 1-month post CAR-T, 80 patients were evaluable for CNS response and 71 patients in the entire cohort were evaluable for systemic response. Similarly, at 3-months these numbers were 66 and 60, respectively. Objective response rates (ORR) were 75% and 80% at 1-month for CNS and systemic disease respectively, while corresponding ORRs at 3-months were 68% and 76.7%. At 1- and 3-months timepoint 36 (45%) and 33 (50%) patients, respectively achieved CNS complete remission (CR), while 44 (62%) and 42 (70%) patients respectively achieved systemic CR. 1- and 2-year PFS for entire cohort were 25% (95%Cl 15% - 34%) and 16% (95%Cl 8.5% - 28%) respectively, while 1- and 2-year OS were 46% (95%Cl 36% - 59%) and 31% (95%Cl 22% - 46%). Non-relapse mortality (NRM) were 4.6% (95%CI, 1.8% -12%) and 7.2% (95%CI 2.9% - 18%) at 1- and 2-year. Cumulative incidence of relapse at 1- and 2-year were 73% (95%Cl 63% - 83%) and 77% (95%Cl 68% - 88%), respectively. ORRs for CNS response in patients with active CNS disease at 1-month and 3-month interval were 71% (n=45) and 60% (n=31). Similarly, ORR for systemic response with active CNS disease at 1-month and 3-month interval were 85% (n=43) and 74.3% (n=32).The 2-year PFS for patients with and without active CNS disease at CAR-T infusion were 12% (95%Cl 5.4% - 27%) and 28% (95%Cl 12% - 65%) respectively, with a corresponding OS of 25% (95%Cl 15% - 41%) and 58% (95%Cl 37% - 91%). ( Figure 1) The 2-year NRM rates for patients with and without active CNS disease at CAR-T infusion were 4.6% (95%Cl 1.5% - 14%) and 14% (95%Cl 3.6% - 53%) respectively, while the cumulative incidence of relapse in similar order were 83% (95%Cl 73% - 95%) and 58% (95%Cl 39% - 88%). Conclusion In this largest known case series to date, CAR-T therapy appeared safe and feasible in patients with SCNSL, but is associated with high rates of treatment failure, particularly in patients with active CNS disease at CAR-T infusion. This warrants further study of optimal CNS-directed treatment strategies prior to CAR-T, development of novel cellular therapy platforms or consideration of post CAR-T maintenance therapy in these high-risk patients.

Adverse events and efficacy of second-round CAR-T cell therapy in relapsed pediatric B-ALL.

Chimeric antigen receptor (CAR) T-cell therapy has transformed the treatment approach for pediatric patients suffering from relapsed/refractory B-cell acute lymphoblastic leukemia (B-ALL). However, there was a paucity of data on the challenges associated with second-round CAR-T therapy in this population. Medical records of nine pediatric patients who received second-round CAR-T therapy in a single center from June 2019 to May 2023 were analyzed. Throughout the course of the clinical trial, we evaluated adverse events including CRS, CRES, infections, hematologic toxicity, and organ injury, as well as CAR-T responses. Except for one patient who chose CART therapy due to testicular relapse, the remaining patients had indications for CAR-T therapy due to relapse with bone marrow alone or combined with other site. There were no difference between the transfusion dose of CART1 and CART2. No differences of incidence and grade of CRS was found between the first-round CAR-T therapy (CART1) and second-round CAR-T therapy (CART2). Additionally, we found that the incidence of CRES was higher for CART1(3/9,33.3%) than CART2(1/9,11.1%). Our findings revealed that there were no differences of IL-2, IL-4, IL-6, IL-10, IFN-γ, and TNF-α between CART1 and CART2, but the peak level of IL-17A was significantly higher in patients receiving CART1 compared to those receiving CART2 (p = .011). Early and late infection rates after CART1 were higher than CART2. Based on the dynamic changes of ANC, hemoglobin and platelet, ANC, and platelet were reduced obviously post CART. It seems that the incidences of severe thrombocytopenia and severe anemia were higher in the CART1 group compared to CART2. The MRD-negative CR rates for CART1 and CART2 are 100% and 44.4%, respectively (p = .029). All patients experienced events (relapse, chemotherapy, transplantation, or death) after receiving CART2, including one died, three discharged automatically, and the remaining five patients survived. Although the remission rate of CART2 is not as high as the CART1 due to the severity of the disease, its safety regarding CRS, CRES, infections, and organ injury is still excellent. Therefore, CART2 remains a viable option for treating pediatric relapsed B-ALL.