Kenderian, Saad S.

Abstract CD19-directed chimeric antigen receptor T (CART19) cell therapy has shown remarkable outcomes in B cell malignancies and was FDA approved in multiple indications, but durable remissions are limited to ~40%. Inhibitory myeloid cells in the tumor microenvironment have been found to suppress T cell expansion and contribute to CART19 failure. Here, we studied interactions between monocytes, CART19, and tumor cells to understand the impact of monocytes on CART19 effector functions. First, CD28-costimulated CART19 (CART19-28ζ) generated in the lab from healthy donors were cocultured with JeKo-1, a CD19+ mantle cell lymphoma cell line, and freshly isolated monocytes or ex vivo differentiated M2-like macrophages. M2-like macrophages were generated by incubating fresh monocytes with rhGM-CSF followed by coculturing with JeKo-1. CART19 antigen-specific proliferation was significantly inhibited by M2-like macrophages but not fresh monocytes (JeKo-1+CART19 vs JeKo-1+M2+CART19, p=0.00503). Transwell assays indicated that suppression from M2-like macrophages was not contact-dependent. IL-1 receptor antagonist (IL-1ra) was significantly elevated in M2-like macrophage coculture supernatant (JeKo-1+Mono+CART19 vs JeKo-1+M2+CART19, p=0.0292) and intracellularly in M2-like macrophages after coculture (90%+). We therefore hypothesized that M2-like macrophages inhibit CART19 by secreting IL-1ra, which blocks IL-1 signaling in CART19. We interrogated the role of IL-1ra in CART19. JeKo-1 was cocultured with CART19, supplemented with rhIL-1β only, IL-1β + IL-1ra, or IL-1β +IL-1ra + IL-1ra neutralizing antibody (neuAb). CART19 antigen-specific proliferation was improved by IL-1β (PBS vs IL-1β, p<0.0001). IL-1ra inhibited IL-1β-dependent CART19 proliferation (IL-1β vs IL-1β+IL1ra p=0.0006), which was restored by IL-1ra neutralization (IL-1β+IL-1ra vs IL-1β+IL-1ra+IL-1ra neuAb, p=0.0215). Additionally, expression of IL-1RI, the receptor of IL-1β and IL-1ra, was measured on T cells after coculturing CART19, JeKo-1, and M2-like macrophages. M2-like macrophages downregulated IL-1RI expression on CART cells, which is a potential mechanism of blocking CART response to IL-1β, resulting in further suppression of CART proliferation (JeKo-1+M2+CART19 vs JeKo-1+CART19, p=0.001). Next, we assessed the impact of IL-1ra on CART cell functions in the presence of M2-like macrophage in a mantle cell lymphoma xenograft model. NOD-SCID-γ−/- (NSG) mice were subcutaneously injected with human macrophages and luciferase+ JeKo-1 cells. Upon tumor engraftment by bioluminescent imaging, mice were randomized to treatment with CART19 + IL-1ra neuAb or control IgG for 3 weeks. CART19 + IL-1ra neuAb led to improved antitumor activity (IL-1ra neuAb vs control IgG, p=0.0033). Overall, our study revealed a role of IL-1ra in macrophage-induced CART inhibition mediated by blocking IL-1β signaling through IL-1RI. Citation Format: Kun Yun, Reona Sakemura, Truc Huynh, Claudia Manriquez Roman, Olivia Sirpilla, Carli Stewart, James Girsch, Ekene Ogbodo, Ismail Can, Jennifer Feigin, Long Mai, Hong Xia, Brooke Kimball, Makena Rodriguez, Lionel Kankeu Fonkoua, Mehrdad Hefazi, Michael Ruff, Elizabeth Siegler, Saad Kenderian. Immunosuppressive monocytes suppress CART19 functions through modulation of the IL-1 pathway [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 6813.

Abstract Oncocytic carcinoma (Hurthle cell carcinoma) has the highest incidence of metastasis among the differentiated thyroid cancers. Metastatic disease is reported at the initial diagnosis in 10-20% of patients and 34% overall. Thyroid-stimulating hormone receptor (TSHR) expression is limited to the thyroid gland. It is abundantly expressed on thyroid tumor cells, making TSHR a compelling target for advanced thyroid cancer diagnostics and therapeutics. We developed a potent anticancer strategy for treating oncocytic carcinoma using a novel thyroid hormone stimulating receptor (TSHR)- targeted (chimeric antigen receptor) CAR T cell therapy. TSHR CAR T was generated by transducing T cells derived from healthy donors. In vitro effector functions (cytotoxicity, proliferation, degranulation) were tested in TSHR+ tumor models, and subsequent in vivo studies using NSG mice were performed to assess anti-tumor activity efficacy. We observed strong anti-tumor activity against metastatic oncocytic carcinoma cell line XCT.UC1 using the TSHR CAR T therapy in vivo. Re-challenging treated mice with XCT.UC1 cells reactivated TSHR CART cells with enhanced proliferation and complete suppression of tumor growth of the newly injected tumor cells. Our work represents a promising strategy to improve treatment outcomes of patients with metastatic oncocytic carcinoma that may provide a durable response. Citation Format: Justyna J. Gleba, Aylin Alasonyalilar-Demirer, Matthew Pawlush, Claudia Manriquez-Roman, Elizabeth L. Siegler, Robert C. Smallridge, Abba Zubair, Han W. Tun, Saad S. Kenderian, John A. Copland. Novel TSHR CAR T therapy for targeting oncocytic carcinoma [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 5082.

Abstract Despite the remarkable efficacy of chimeric antigen receptor T -cell therapy (CART) for the treatment of B-cell malignancies, durable remission remains limited often due to tumor relapse. We have previously demonstrated that tumor-derived extracellular vesicles (EVs) induced CART cell failure in preclinical models. To characterize the impact of tumor EV induced CART cell dysfunction, we assessed microRNA (miRNA) profiles contained within tumor EVs from two independent patient cohorts and studied how they contributed to CART dysfunction. Our first cohort included patients with chronic lymphocytic leukemia (n=50). We previously showed that CLL patient derived EVs induce a state of CART cell dysfunction. To understand this dysfunction, we interrogated the miRNA cargo significantly enriched in CLL EVs and how their coculture impacts CART signaling by RNAseq. Here, we found a significant enrichment in miR-125a within CLL EVs as compared to healthy donor controls (p=.0001). CART cocultured with CLL EVs showed alterations in T cell activation pathways, where miR-125a targets TNFAIP3 and NFkB pathways were activated. These findings implicate miR-125a from CLL EVs in CART dysfunction. Next, we aimed to validate the impact of miRNA on CART cell outcomes in the clinic. We interrogated miRNA profiles from patients with diffuse large B cell lymphoma (DLBCL) treated with CART cell therapy (CART19-28ζ, axicabtagene ciloleucel). EV miRNA cargo was compared between responders (complete remission at 6 months, n=10) and non-responders (no response 1 month post CART19, n=10) to identify differentially enriched miRNAs across groups. miR-125a was again significantly upregulated in EVs of non-responders as compared to responders to CART19 treatment (fold change=3.28, padj=.018). To study the direct effect of miR-125a on CART cell functions, we generated and studied the effector functions of CART19-28z following transfection with miR-125a or negative miR control. CART19 cells transfected with miR-125a showed a dose dependent decrease in killing of lymphoma cells as compared to miR-control (p=.0001). miR-125a also significantly increased the rate of apoptosis in CART19 cells (fold change=1.95, p=.024) and decreased the level of CART proliferation (fold change=.71, p=.013) as compared to controls. Notably, miR-125a did not impact tumor cell growth, further verifying a direct CART effect. In summary, our studies demonstrate the impact of tumor derived miRNAs on CART cell outcomes. They identify that miR-125a is 1) associated with CLL EV induced CART dysfunction, 2) significantly elevated in non-responders to CART therapy in the clinic, and 3) able to decrease CART19 efficacy through reduced CART killing/proliferation and increased apoptosis. These results highlight a novel mechanism of CART19 failure induced through miRNA cargo delivery by tumor-derived EVs and the role of miR-125a in inducing CART19 dysfunction. Citation Format: Olivia Sirpilla, R. Leo Sakemura, Ismail Can, Truc N. Huynh, James H. GIrsch, Claudia Manriquez Roman, Carli M. Stewart, Kun Yun, Ekene J. Ogbodo, Long Mai, Omar Gutierrez Ruiz, Makena Rodriguez, Brooke Kimball, Hong Xia, Jose C. Villasboas, Stephen Ansell, Nora Bennani, Patrick B. Johnston, Jonas Paludo, Januario Castro, Mohamed Kharfandabaja, Sameer Parikh, Neil Kay, Yi Lin, Elizabeth Siegler, Saad Kenderian. Tumor-derived microRNA125a induces CART cell apoptosis and failure in B cell malignancies [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 3841.

This case-control study examines the incidence and risks of myeloid neoplasms in adults treated for B-cell lymphoproliferative disorders or multiple myeloma.

INTRODUCTION Richter transformation (RT) is the histologic transformation of CLL/SLL into an aggressive lymphoma, most commonly diffuse large B-cell lymphoma (DLBCL). We previously reported an incidence of 0.5% per year of RT in patients with newly diagnosed CLL and an incidence of 1% per year following initiation of therapy (Parikh, BJH, 2013). It is unknown whether these incidences have changed in the novel agent era. METHODS We identified patients with previously untreated CLL/SLL in the Mayo Clinic CLL Database who were seen within 12 months of diagnosis. Only patients with biopsy-proven DLBCL with histopathology confirmation at Mayo Clinic were included. Cumulative incidence methodology was used to display the time to development of RT with death as a competing risk (both from time of initial CLL/SLL diagnosis, and from start of CLL directed therapy). We defined the time period prior to February 2014 (FDA approval of ibrutinib for CLL) as the pre-novel agent era and the time period starting February 2014 as the novel agent era. Using Cox regression analysis, we compared the incidence of RT, both after initial CLL diagnosis and after initiation of CLL therapy, between patients diagnosed with CLL in the pre-novel agent era versus the novel agent era. RESULTS Between 1/2000 and 4/2023, 3347 patients were seen at Mayo Clinic. The median age at diagnosis was 65 years (range 21-97 years), and 66% patients were male. Baseline characteristics of patients at the time of CLL and RT diagnoses between the two treatment eras were similar, including distance in miles of primary residence from Mayo Clinic ( Table 1). The median follow-up for the entire cohort was 5.6 years (9.5 years for the pre-novel agent era cohort and 3.2 years for the novel agent era cohort). A total of 82 patients were diagnosed with RT (69 in the pre-novel agent era and 13 in the novel agent era). Overall, the 1-, 5- and 10-year cumulative incidence rates for RT from the time of CLL/SLL diagnosis were 0.6% (95% CI: 0.4-0.9%), 1.8% (95% CI: 1.3-2.3%), and 3.0% (95% CI: 2.4-3.8%), respectively. Among the patients who received CLL/SLL therapy (n=1382), the 1-, 5-, and 10-year incidence rates for RT from the time of treatment start were 0.3% (95% CI: 0.1-0.8%), 3.3% (95% CI: 2.4-4.5%), and 4.9% (95% CI: 3.7-6.5%), respectively. Among 1981 patients diagnosed with CLL/SLL in the pre-novel agent era, the 1- and 5-year incidence rates for RT from the time of diagnosis were 0.6% (95% CI: 0.4-1.1%) and 2.1% (95% CI: 1.5-2.8%), respectively. Among 1366 patients diagnosed with CLL/SLL in the novel agent era, the 1- and 5-year incidence rates following CLL/SLL diagnosis were 0.5% (95% CI: 0.2-1.1%) and 1.1% (95% CI: 0.6-2.2%), respectively. The RT incidence from time of CLL/SLL diagnosis was not significantly different between the pre-novel agent and novel agent era patients (hazard ratio [HR] 1.6, 95%CI 0.9-3.0, p=0.13). Patients who received CLL/SLL treatment in the pre-novel agent era (n=926) and novel agent era (n=456) had subsequent 1-year incidence rates of RT of 0.3% (95% CI: 0.1-1.0%) and 0.2% (95% CI: 0.0-1.8%), respectively. The 5-year incidence rates for these groups were 3.7% (95% CI: 2.6-5.2%) and 1.9% (95% CI: 0.7-5.0%), respectively. Although an increased risk of RT after CLL/SLL directed therapy was observed in the pre-novel agent era compared to the novel agent era (HR 2.4, 95%CI: 0.9-6.1, p=0.07; Figure 1), this did not cross the threshold of statistial significance. Among patients diagnosed in the pre-novel agent era who developed RT (n=69), CLL treatment prior to RT included: none, n=19 (28%); chemoimmunotherapy only, n=36 (52%); and novel agent, n=14 (20%; includes 11 treated with prior chemoimmunotherapy also). In contrast, among patients diagnosed in the novel agent era who developed RT (n=13), CLL treatment prior to RT included: none, n=8 (62%); and novel agent, n=5 (38%). CONCLUSIONS Patients who received CLL/SLL directed treatment appear to have a lower risk of RT in the novel agent era. This may be driven by the fact that none of the patients who developed RT in the novel agent era received chemoimmunotherapy. Whether novel agent use for CLL/SLL suppresses the development of RT or avoids the risk associated with cytotoxic chemotherapy-induced clonal evolution requires further study. Although limited by length of follow-up, our findings challenge the notion that RT incidence will increase in parallel with CLL patients living longer with novel agent treatments.

Background: Chimeric antigen receptor (CAR) T cells have repeatedly demonstrated capacity to induce high rates of response and durable remissions for B cell cancers. In contrast, CAR T cells for the treatment of acute myeloid leukemia (AML) have not yet achieved this impact. We previously demonstrated that CD123 is expressed on AML blasts at high frequency, thus making it an attractive target antigen for AML-directed CAR T cells. Methods and Results: We conducted a pilot study of CD123-directed CAR T cells (CART-123) in adults with relapsed or refractory AML. The primary objective was safety with a secondary objective of anti-leukemia efficacy. Twenty-two subjects were screened, and 20 were eligible for the trial. Fludarabine and cyclophosphamide were used for lymphodepletion (LD). Twelve subjects were infused with CART-123. There were two treatment-related deaths due to cytokine release syndrome (CRS) and infection. Four subjects (33%) achieved complete response with incomplete count recovery (CRi), three subjects had progressive disease, and five had stable disease. Of the four who achieved CRi, one subject remains alive in remission after a relapse and subsequent consolidative hematopoietic stem cell transplant (HSCT). One other subject is alive after HSCT following CART-123 failure. There was evidence of CAR T cell expansion and ten subjects (83%) experienced clinical CRS ranging from Grade I to Grade V. There was no neurotoxicity. To address the apparent paradox of high rates of CART-123 bioactivity (clinical CRS and in vivo expansion) co-occurring with low rates of response, we hypothesized that cytokines produced during CRS may undermine the anti-AML effect of CART cells. We obtained serum drawn from trial subjects at baseline (prior to LD chemotherapy) or during CRS. Serum drawn during CRS promotes primary AML survival in cell culture, while matched baseline serum from the same subjects does not. Individual cytokines secreted during CRS that signal through receptors expressed on myeloid progenitors (such as GM-CSF and Flt3 ligand) reproduced this survival advantage in primary AML blasts when tested at physiologically relevant levels. In contrast, these cytokines did not produce a pro-survival effect in primary patient B-ALL blasts. Crucially, candidate myeloid-acting cytokines, as well as serum drawn during the peak of clinical CRS, promoted resistance of AML to killing by CART-123 in vitro. Using scRNAseq of bone marrow aspirates from subjects on this clinical trial, we found that GM-CSF and FLT3L were most frequently expressed by CD4+ T cells. Exposure of primary AML samples to CRS cytokines led to upregulation of signaling (e.g. JAK/STAT5) and pro-survival pathways. In previous work in B-ALL, we showed that relative resistance to killing can translate to a functional deficit in CART-19 due to development of exhaustion in the CART cells. We similarly find that that exposure to GM-CSF reduces AML blast sensitivity to CART-123, and that the persistence of antigen leads to exhaustion in CART cells (Figure 1). Specifically, co-incubation of CART-123 cells and cytokine-exposed primary AML blasts leads to increased populations of PD-1+/CD39+/CTLA4+/LAG3+ CAR T cells, consistent with an exhaustion phenotype. Finally, we found that anti-apoptotic effects of cytokines can be prevented, and CART-123 killing of AML can be restored, via ruxolitinib blockade of JAK/STAT signaling in both in vitro and in vivo settings. Significance: Our work reveals CRS as active in undermining CART-123 lethality first by promoting survival of AML, and subsequently by exhausting CAR T cells. This is in stark contrast to its role in lymphoid malignancies and underscores biological differences in myeloid versus lymphoid neoplasms. These results highlight a need to tailor therapy to limit cytokine effects on AML blasts to improve outcomes with AML-directed CAR T cell therapy.

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.

INTRODUCTION We aim to identify factors that impact outcomes of venetoclax for patients with CLL treated in routine practice at a tertiary center. We report on the use of venetoclax in the most frequently encountered disease scenarios: first-line, relapsed/Bruton tyrosine kinase inhibitor (BTKi)-naïve, and relapsed/BTKi-exposed. METHODS We identified patients who received venetoclax therapy for CLL (between 4/2012-4/2023) from the Mayo Clinic CLL Database. Undetectable measurable residual disease (uMRD) was defined as <1 CLL cell per 10,000 leukocytes using 8-color flow cytometry on peripheral blood (PB) or bone marrow (BM). Overall survival (OS) was defined as the time from venetoclax start until date of death or last known to be alive. Treatment-free survival (TFS) after venetoclax was defined as the time from venetoclax start until the earliest of date of next treatment, or death. Kaplan-Meier was used to display OS and TFS. Multivariable Cox proportional hazards regression models were used to estimate associations of factors with time-to-event outcomes. RESULTS A total of 155 patients received venetoclax: firstline therapy (in combination with obinutuzumab, n=55) and relapsed CLL (n=100; 17 had relapsed/BTKi-naïve CLL, and 83 had previously received BTKi [55 with progression after BTKi], relapsed/BTKi-exposed). The median follow-up for the cohorts of first-line therapy, relapsed/BTKi-naïve, and relapsed/BTKi-exposed was 12.9 months, 37.0 months, and 27.6 months, respectively. Baseline characteristics at the time of venetoclax initiation for all patients are shown in Table 1. The median TFS for the overall cohort was 39.0 months. The median OS was 54.6 months. Among patients treated with venetoclax as first-line therapy (n=55), the 2-year TFS ( Figure 1) and 2-year OS rates were both 91%. MRD testing was performed in 28 patients and was uMRD in 23 (82%) patients (only PB assessed, n=7; only BM assessed, n=2; PB and BM assessed, n=14). Detectable MRD was identified in 3 patients, and 2 patients had discordant results (PB uMRD and BM detectable disease). Among patients treated with venetoclax in the relapsed/BTKi-naïve setting (n=17), the 2-year TFS rate was 73% ( Figure 1) and the 2-year OS rate was 100%. MRD testing was performed in 7 patients and was uMRD in all 7 (100%) (only PB assessed, n=3; only BM assessed, n=2; PB and BM assessed, n=2). The median time to first uMRD result was 14.1 months. Among relapsed/BTKi-exposed venetoclax-treated patients (n=83), the median TFS was 26.9 months ( Figure 1), and the median OS was 39.4 months.In this subgroup, the median TFS for patients with (n=55) and without (n=28) prior disease progression on prior BTKi were 22.3 and 42.3 months, respectively. Median TFS with venetoclax monotherapy (n=30) was 24.0 months, venetoclax in combination with rituximab (n=37) was 26.9 months, and venetoclax in combination with obinutuzumab (n=16) was 39.0 months. BTKi-exposed patients that were chemotherapy-naïve (n=27) and chemotherapy-exposed (n=56) had median TFS of 29.1 and 24.0 months, respectively. MRD testing was performed in 28 patients and was uMRD in 16 (57%) patients (only PB assessed, n=9; only BM assessed, n=2; PB and BM assessed, n=5). Detectable MRD was identified in 11 patients, and 1 had discordant results (PB uMRD and BM detectable disease). The median time to first uMRD result was 11.5 months. TP53 disruption, unmutated IGHV genes, older age, complex karyotype (CK; defined as more than 3 chromosomal aberrations on CpG stimulated karyotype), and disease progression on prior BTKi were associated with shorter TFS in the overall cohort on univariate analysis. TP53 disruption, older age, CK, and disease progression on prior BTKi were associated with shorter OS in the overall cohort on univariate analysis. Multivariable analysis was performed by including only those patients where all variables significant in univariable analysis were available (OS model n=65, TFS model n=53). In these models, only CK was significantly associated with shorter TFS (HR 8.5; 95%CI 2.5-29.1; P<0.001) and shorter OS (HR 4.1; 95%CI 1.2-14; P=0.03). CONCLUSIONS Patients with BTKi-exposed CLL, particularly those with prior disease progression on BTKi, had worse outcomes. Our study identified CK as one of the most important baseline predictors of adverse TFS and OS in the overall cohort of patients, supporting karyotype assessment for prognostication prior to venetoclax treatment.

Background: Patients (pts) receiving FDA-approved chimeric antigen receptor T-cell (CAR-T) therapy or Bispecific antibody Teclistamab (Tec) are commonly managed in the inpatient setting given the common adverse events such as cytokine release syndrome (CRS) and immune cell-associated neurotoxicity syndrome ICANS. We have previously reported that hospital-based outpatient (HBO) management of pts receiving CAR-T is feasible and safe (Bansal et al, ASH2022). In 2023, HBO management at our institution began incorporating home health visits and management of grade 1 CRS in outpatient setting for select pts receiving standard of care (SOC) CAR-T. Here, we report outcomes of our updated practice. Methods: We retrospectively analyzed medical records and remote monitoring data of adult pts who received SOC CAR-T or Tec between 10/2020 and 7/2023 at Mayo Clinic, Rochester under an IRB approved protocol. Results: In 3/2023, pts deemed to be low risk for severe CRS (fever onset >= 3 days from infusion, CRP<100) received HBO management for grade 1 CRS, including outpatient administration of tocilizumab. If CRS improved or resolved, outpatient monitoring was continued. If CRS persisted within the observation period on HBO, pts were admitted. Recurrent CRS after the first episode were all managed inpatient. Nine pts met these criteria for HBO CRS management and their outcomes were compared to those who received initial inpatient (INPT) CRS management (INPT, n=17) during the same timeframe, as well as the outcome of 164 pts who had CRS management INPT prior to our practice change (Table 1). Two-third of the pts with initial management of CRS outpatient did not require hospitalization. Median time to hospitalization trended later than those managed inpatient at the onset of CRS. The duration of hospitalization was comparable for all pts admitted between initial HBO and INPT CRS management. However with fewer admissions in the initial CRS HBO group, the average hospitalization days (LOS) per patient treated for that group was lower compared to initial INPT CRS management. Data on additional pts will be presented at ASH. In 1/2023, pts on RPM with no ongoing CRS symptoms, no language barriers, and no compliance concerns received home health visits during weeks 3 and 4 post CAR-T infusion in place of clinic visits on HBO. Home health visit team communicated with HBO staff to review assessment and plan. Changes in HBO utilization will be presented. Finally, 24 pts received 223 Tec infusions on HBO. Median age was 66 years, 15 (61%) were males, 9 (38%) had high risk cytogenetics. The median prior lines of therapy was 5. Among these pts, 220/223 (99%) doses were performed on HBO and 204/220 (93%) infusions never required admission for management. Twenty pts enrolled in RPM (Figure 1). An average of 2 alerts were generated per patient during the 2 week period and median time from infusion to alert was 1.5 days. Majority of alerts were resolved over a phone call and only 13/114 (11%) alerts required a physician visit/hospital admission. Of the 16 Tec infusions resulting in admission, 4/16 (25%) required re-admission resulting in a total of 20 hospitalizations. Admissions mostly occurred during step-up dosing (18/20; 90%). Most common reason for first admission was fever (13/16, 85%) and median time to admission was 1 day from infusion. Median LOS was 1.5 days (range, 0-12). In terms of CRS, majority were Grade 1 (12/13, 93%) which were managed with steroids (dexamethasone/ prednisone) alone. One patient had CRS grade 4 event, in the setting of concurrent decompensation during dialysis, and was treated with steroids, tocilizumab, vasopressor, CRRT, thoracentesis, intubation and mechanical ventilation. The rate of second CRS event after management of first CRS with steroid (dexamethasone/ prednisone) was 15% (2/13). These second CRS episodes also resolved with steroid alone. Data on additional pts receiving Tec will be presented at ASH. Conclusion: Our data showed that additional advances in outpatient practice, including initial outpatient management of CRS and outpatient administration of Tec step up dosing are feasible, safe and reduce hospital resource utilization.

Background:Patients with R/R CLL/SLL who experience intolerance to or disease progression after Bruton tyrosine kinase inhibitor (BTKi) and venetoclax treatment have no established standard of care and poor outcomes, indicating a critical unmet need. Liso-cel, an autologous, CD19-directed, 4-1BB CAR T cell product, has demonstrated efficacy in large B-cell lymphoma and CLL/SLL. In the primary analysis of the phase 1/2, single-arm, multicenter TRANSCEND CLL 004 (NCT03331198) study, a single administration of liso-cel demonstrated rapid, deep, and durable responses and a manageable safety profile in patients with R/R CLL/SLL, including those with progression on previous BTKi and venetoclax failure (Siddiqi T, et al. Lancet 2023). The primary endpoint was met in the prespecified subset of efficacy-evaluable patients with disease progression on BTKi and venetoclax failure (primary efficacy analysis set [PEAS]) at a target dose of 100 × 10 6 CAR + T cells (null hypothesis: ≤ 5%) with the rate of complete response/remission (CR) and CR with incomplete marrow recovery (CRi) by an independent review committee (IRC) per 2018 International Workshop on CLL (iwCLL) criteria at 18.4% ( P = 0.0006). Here we report results from TRANSCEND CLL 004 with a median follow-up of 23.5 months. Methods: Patients must have received ≥ 2 prior lines of therapy, including a BTKi. Eligible patients received liso-cel at a target dose of either 50 × 10 6 (dose level [DL] 1) or 100 × 10 6 (DL2) CAR + T cells after lymphodepleting chemotherapy. The primary endpoint was CR/CRi in the PEAS at DL2. Key secondary endpoints were ORR and rate of undetectable MRD (uMRD; 10 −4 by next-generation sequencing) in blood. All null hypotheses were tested at the primary analysis and not retested in this analysis. Results:Of 137 leukapheresed patients, 118 received liso-cel (safety set), 97 (DL1 = 9; DL2 = 88) were efficacy evaluable, and 54 (DL1 = 4; DL2 = 50) were in the PEAS. In the safety set, median (range) age was 65 years (49-82), 83% had high-risk cytogenetics (del[17p], 42%; TP53 mutation, 47%; unmuted immunoglobulin heavy-chain variable gene, 47%; ≥ 3 chromosomal aberrations, 61%), median (range) lines of prior therapy was 5 (2-14), and all patients had prior BTKi. As of data cutoff (February 28, 2023), median (range) on-study follow-up was 23.5 months (0.4-59.6) for the safety set. In the PEAS at DL2, CR/CRi rate was 20% (95% CI, 10.0-33.7; Table 1). ORR was 44% (95% CI, 30.0-58.7). One patient who had best overall response (BOR) of partial response/remission (PR) at primary analysis had deepened to CR/CRi at 18 months without any additional therapy. Of 9 patients who had BOR of CR/CRi at the primary analysis, 8 had ongoing CR/CRi and 1 completed the study with the last assessment as CR/CRi. The uMRD rate was 64% (95% CI, 49.2-77.1) in blood and 60% (95% CI, 45.2-73.6) in marrow. Median (95% CI) duration of response was 35.3 months (12.4-not reached [NR]) and median duration of CR/CRi was NR. Median (95% CI) PFS was 11.9 months (5.7-26.2). Median (95% CI) OS was 30.3 months (15.0-NR). The efficacy outcomes were similar in the full population at DL2. Of 16 patients who had BOR of CR/CRi at primary analysis, 10 had ongoing CR/CRi. In the safety set, rates of any-grade and grade ≥ 3 treatment-emergent AEs were similar across age groups (Table 2). The rate of any-grade cytokine release syndrome (CRS) was 85% (grade 3, 8%; no grade 4/5) and neurological events (NE) was 45% (grade 3, 18%; grade 4, 1%; no grade 5); 69% received tocilizumab and/or corticosteroids for CRS/NEs. Median (range) time to onset and resolution was 4 days (1-18) and 6 days (2-37) for CRS and 7 days (1-21) and 7 days (1-83) for NEs, respectively. Prolonged cytopenia (grade ≥ 3 at Day 30 after liso-cel infusion), grade ≥ 3 infections, hypogammaglobulinemia, tumor lysis syndrome, second primary malignancy, and macrophage activation syndrome occurred in 54%, 18%, 15%, 11%, 9%, and 3%, respectively. Forty-five (33%) of 137 leukapheresed patients died after liso-cel infusion (disease progression, n = 27 [20%]; AE, n = 6 [4%]; other reasons, n = 12 [9%]). Conclusions: With longer follow-up, liso-cel continued to demonstrate durable CR/CRi, high uMRD rates, and a manageable safety profile in patients with heavily pretreated, high-risk R/R CLL/SLL. The safety results from longer follow-up were similar to those reported in the primary analysis with no new safety signals and were consistent across age groups.