Kymera Therapeutics Research Articles

Phase 1 trial of KT‐333, a STAT3 degrader, in patients with relapsed or refractory lymphomas, large granular lymphocytic leukemia and solid tumors

Background: KT-333 is a first-in-class, potent, highly selective, heterobifunctional small molecule degrader of the signal transducer and activator of transcription 3 (STAT3) protein. Aberrant activation of STAT3 resulting from activating mutations or deregulated cytokine signaling is known to underlie a variety of malignancies including peripheral T-cell lymphomas (PTCL), cutaneous T-cell lymphoma (CTCL), and large granular lymphocytic leukemia (LGL-L). However, selective targeting of STAT3 has been a therapeutic challenge. In preclinical xenograft studies, treatment with KT-333 resulted in durable tumor regressions in STAT3-dependent T cell lymphomas. Pharmacokinetic (PK) and pharmacodynamic (PD) analysis demonstrated that STAT3 degradation of >90% in tumor for 48 h is required for anti-tumor efficacy. Methods: The ongoing multicenter Phase 1a/1b study evaluates the safety, tolerability, PK, PD and preliminary clinical activity of KT-333 administered as a weekly IV infusion in 28-day cycles. The Phase 1a will identify the recommended phase 2 dose based on dose limiting toxicity (DLT) observed in Cycle 1. Eligible patients include those with advanced solid tumors and relapsed or refractory B- and T-cell lymphomas, Hodgkin’s lymphoma, and LGL leukemia. Serial blood samples are collected in Cycle 1 and Cycle 2 to measure KT-333 plasma concentrations and STAT3 protein expression in PBMCs (using targeted mass spectrometry). STAT3 degradation and the impact on tumor biology is measured in patients with accessible tumors. Results: As of February 3, 2023, seven patients have been treated in the first two dose levels (DLs) in Phase 1a, including patients with CTCL and PTCL with median age of 65 (range 57, 74) and performance status of 0 (n = 1) and 1 (n = 6). No DLTs have been observed and no patients have discontinued KT-333 due to an adverse event. The most common adverse events are Grade 1 and 2 and include constipation, fatigue, abdominal pain, dizziness, and nausea. PD data in blood demonstrated robust and sustained STAT3 degradation with mean maximum decrease of PBMC STAT3 levels after dosing on Days 1 and 8 of 66% in DL1 (n = 4) and 70% in DL2 (n = 2). PK results were in line with the modeled predictions. Conclusion: The emerging clinical data suggest that KT-333 is a potent degrader of STAT3 as demonstrated in PBMCs at doses that are well tolerated. These data provide the first evidence of STAT3 targeted protein degradation in humans and point to the potential of heterobifunctional degraders for targeting previously undruggable targets. It is projected that higher doses of KT-333 will achieve the predicted degradation profile in tumors that may translate into clinical benefit in patients with STAT3-dependent T cell malignancies. Accrual into the study is ongoing, and analyses from additional patients will be presented at the meeting. The research was funded by: Kymera Therapeutics Keywords: Aggressive T-cell non-Hodgkin lymphoma, Cutaneous non-Hodgkin lymphoma, Therapeutics and Clinical Trials in Lymphoma Conflicts of interests pertinent to the abstract. A. Olszewski Consultant or advisory role: Schrodinger, Genmab Research funding: Genentech, Schrodinger, PrecisionBio, Adaptive biotechnologies Z. Epstein-Peterson Honoraria: OncLive Research funding: Kymera, Viracta, Amgen R. Perea Employment or leadership position: Kymera Stock ownership: Kymera; Pfizer A. Gollerkeri Employment or leadership position: Kymera Stock ownership: Kymera, Pfizer J. Dey Employment or leadership position: Kymera Therapeutics Stock ownership: Kymera Therapeutics C. Klaus Employment or leadership position: Kymera Therapeutics Stock ownership: Kymera Therapeutics S. Agarwal Employment or leadership position: Kymera Stock ownership: Kymera J. Gollob Employment or leadership position: Kymera Stock ownership: Kymera A. Shastri Consultant or advisory role: Janssen Pharmaceuticals, Gilead Sciences, Rigel Pharmaceuticals and Kymera Therapeutics Honoraria: NACE & PeerView. Research funding: Kymera Therapeutics

Triana launches for molecular glues

Triana Biomedicines has launched with $110 million in funding from investors that include Atlas Venture and Pfizer Ventures. The Boston-based firm develops small-molecule “molecular glues” that stabilize existing interactions, or create new ones, between two proteins, thus altering the fate or functionality of a disease target. One of the firm’s founders is biochemist Jesse Chen, who was previously with the targeted protein degradation firm Kymera Therapeutics.

A First-in-Class STAT3 Degrader KT-333 in Development for Treatment of Hematologic Cancers

Signal Transducer and Activator of Transcription 3 (STAT3) plays important roles in the transduction of signals from growth factors and cytokines in both normal and malignant cells. Upon activation, STAT3 controls expression of genes that regulate cell growth, survival, differentiation, stemness and cell-cell interactions. Aberrant activation of STAT3 has been observed in many cancers including lymphoma and leukemias through activating mutations, hyper-signaling through upstream regulators or loss of negative feedback regulation. Additionally, STAT3-mediated cross-talk in the tumor microenvironment results in suppression of immune surveillance compromising anti-tumor immunity.STAT3 has been historically considered “undruggable”. Heterobifunctional degraders that recruit endogenous E3 ligases to ubiquitinate substrate proteins leading to their degradation by the proteosome have emerged as a novel therapeutic modality with great potentials to drug undrugged protein targets. Here we introduce a first-in-class, potent and selective STAT3 degrader KT-333 that is being developed for the treatment of hematologic malignancies and solid tumors.KT-333 is a small molecule targeted protein degrader of STAT3 and was discovered by an iterative medicinal chemistry SAR campaign improving parameters such as potency, selectivity and ADME profile. It has high solubility in PBS buffer (103 mg/mL, pH7.4). low to moderate clearance in rat, dog and monkey, and moderate plasma half lives across pre-clinical species.KT-333 exhibits potent and selective degradation of STAT3 with DC 50 of 2.5 -11.8 nM in four anaplastic T cell lymphoma (ALCL) lines. Selective degradation of STAT3 over nearly 9000 proteins, including other STAT family members, was demonstrated by mass spectrometry in human PBMCs . Tumor cells expressing NPM-ALK fusion oncoproteins have activated STAT3 and dependency on STAT3 signaling for survival KT-333 treatment led to rapid apoptosis of these ALK+ALCL cells. To better understand the cellular responses to STAT3 degradation, time-course transcriptomic and proteomic analyses were performed using SU-DHL-1 cells treated with KT-333. Time-dependent changes in both mRNA and protein levels of STAT3-regulated genes and pathways were observed: at 8 h only STAT3 showed significant depletion, at 24 h canonical STAT3 downstream genes including SOCS3, IL-2RA and GRZMB showed modulation and at 48 h, pathways including interferon response and cell cycle were significantly enriched. A comparison of the transcriptomic and proteomic data sets showed high correlation. Furthermore, changes in mRNA and protein levels of bona fide STAT3 regulated targets showed a high degree of concordance between SU-DHL-1 cells and SU-DHL-1 xenograft tumors.Preclinical in vitro experiments have demonstrated that approximately 90% degradation of STAT3 for 48 h was sufficient to drive ALK+ ALCL lines into irreversible cell growth inhibition and death. In vivo xenograft studies of SU-DHL-1 and SUP-M2 ALCL models demonstrated dose-dependent tumor growth suppression. An indirect response model that linked exposure to target degradation was established to describe the relationship between exposure and target degradation in the tumor. Consistent with the in vitro data, PK-PD-efficacy analysis in the SU-DHL-1 xenograft model showed that tumor regression could be achieved with intermittent dosing schedules that achieved ~90% degradation of STAT3 for about 48 h over a weekly or bi-weekly dosing interval. . Based on preclinical ADME and PK/PD/efficacy relationship, KT-333 is predicted to drive tumor regression using weekly doses.In conclusion, we have identified a potent STAT3 degrader as development candidate that can be administered parenterally in the clinic on an intermittent dosing regimen that is predicted to be both efficacious and tolerated in STAT3-dependent hematologic malignancies. DisclosuresLiu: Kymera Therapeutics: Current Employment, Current equity holder in publicly-traded company. Dixit: Kymera Therapeutics: Current Employment, Current equity holder in publicly-traded company. Mayo: Kymera Therapeutics: Current Employment, Current equity holder in publicly-traded company. Dey: Kymera Therapeutics: Current Employment, Current equity holder in publicly-traded company. Yuan: Kymera Therapeutics: Current Employment, Current equity holder in publicly-traded company. Karnik: Kymera Therapeutics: Current Employment, Current equity holder in publicly-traded company. Walther: Kymera Therapeutics: Current Employment, Current equity holder in publicly-traded company. Shi: Kymera Therapeutics: Current Employment, Current equity holder in publicly-traded company. Sharma: Kymera Therapeutics: Current Employment, Current equity holder in publicly-traded company. Rong: Kymera Therapeutics: Current Employment, Current equity holder in publicly-traded company. Yang: Kymera Therapeutics: Current Employment, Current equity holder in publicly-traded company. Gollerkeri: BEAM Therapeutics: Current Employment, Current equity holder in publicly-traded company; Kymera Therapeutics: Current Employment, Current equity holder in publicly-traded company. Gollob: Kymera Therapeutics: Current Employment, Current equity holder in publicly-traded company. DeSavi: Kymera Therapeutics: Current Employment, Current equity holder in publicly-traded company.

Selective STAT3 Degraders Dissect Peripheral T-Cell Lymphomas Vulnerabilities Empowering Personalized Regimens

Introduction: Peripheral T-cell lymphomas (PTCLs) include heterogeneous entities of rare and aggressive neoplasms. The improved understanding of the biological/molecular mechanisms driving T-cell transformation and tumor maintenance has powerfully propelled new therapeutic programs. However, despite this progress, PTCLs remain an unmet medical need. Recurrent aberrations and the deregulated activation of distinct signaling pathways have been mapped and linked to selective subtypes. The JAK/STAT signaling pathway's deregulated activation plays a pathogenetic role in PTCL, including ALCL subtypes. STATs regulate the differentiation/phenotype, survival and cell-growth, metabolism, and drug resistance of T-cell lymphomas as well as host immunosuppressive microenvironments. Although many drugs' discovery programs were launched, a plethora of compounds has failed.Methods: We have discovered heterobifunctional molecules by an iterative medicinal chemistry SAR campaign that potently and selectively degrade STAT3 in a proteasome-dependent manner. Conventional PTCL cell lines and Patient Derived Tumor Xenograft (PDTX) and/or derived cell lines (PDTX-CL), carrying either WT- or mutated-STAT3, were exposed to increasing amounts (50nM⇒5µM) of STAT3-degraders. Proteins and mRNA transcripts (2⇒144hrs) were assessed by deep-proteomics and paired-end RNA sequencing, combined with WB/flow cytometry and qRT-PCR. Cell-titer-glo, cell titer blue, Annexin-V and S-cell cycle analyses were used as readouts. Chromatin accessibility, STAT3 DNA binding, 3D chromosomal architecture reorganization and 5-hmC profiling were assessed by ATACseq, CHIPseq and Hi-C and H3K27ac Hi-CHIP and mass-spectrometry. Drug testing/discovery combinations (96-well-plate) were performed using a semi-automated flow-cytometry. A battery of PTCL PDTX models were tested in pre-clinical trials.Results: Treatment of ALK+ ALCL (SU-DHL1) led to the rapid (~6hrs.) and profound down-regulation of STAT3 followed by the loss of canonical STAT3-regulated proteins (SOCS3, MYC, Granzyme B, GAS1, and IL2RA), without appreciable changes for other STAT family members (STAT1, STAT5b). In vitro, cytoplasmic, nuclear, and mitochondrial STAT3 downregulation was maintained up to 144 hrs. Loss of STAT3 in ALK+/- ALCL and BIA-ALCL cells was associated with major transcriptional changes (7116-10615 and 15114 DEGs in ALK- and ALK+ ALCL, respectively), underscoring public/shared as well as private time-dependent signatures. Main down-regulated pathways included JAK-STAT, MAPK, NF-kB, PI3K, TGFb, and TNFa. Comparison of STAT3 shRNA (ALK+ ALCL) and STAT3 degrader (ALK-/ALK+ ALCL) signatures demonstrated a substantial and concordant gene modulation (24hrs) among all models with the highest overlaps between ALK+ ALCL (Figure 3). To identify direct STAT3 gene targets, we analyzed CHIPseq peaks and predicted bindings sites, demonstrating that canonical genes, i.e., SOCS3, Granzyme B, GAS1, IL2RA, STAT3, and CD30, were significantly downregulated. Conversely, CD58, CD274, and MCH-I/II were upregulated at late time points. By mapping the STAT3 binding sites in ALK+ and ALK- ALCL, we have identified 1077 and 2763 STAT3 peaks within promoter/5‘-/3‘- and distant intergenic regions, corresponding to both coding and non-coding genes. Therapeutically, in vitro treatments led to cell cycle arrest and profound growth inhibition, and over time increased cell death of PTCL cells, including ALCL. Accordingly, growth inhibition of ALCL xenograft and PDTX tumors was also achieved (Figure 2). To identify drugs that could synergize withSTAT3-degrader activity, we tested a compound library (40) targeting pro-tumorigenic PTCL pathways as well as FDA-approved compounds. Ongoing studies are in progress.Conclusion: We have discovered selective STAT3 degraders which control PTCL growth. STAT3 degraders are powerful tools to define the STAT3 pathogenetic mechanisms and dissect genes/pathways to be targeted for T-cell lymphoma eradication. These data provide additional rationale for testing STAT3 degraders in the clinic for the treatment of aggressive malignancies including PTCL/ALCL. [Display omitted] DisclosuresYang: Kymera Therapeutics: Current Employment, Current equity holder in publicly-traded company. Sharma: Kymera Therapeutics: Current Employment, Current equity holder in publicly-traded company. Dey: Kymera Therapeutics: Current Employment, Current equity holder in publicly-traded company. Karnik: Kymera Therapeutics: Current Employment, Current equity holder in publicly-traded company. Elemento: Owkin: Consultancy, Other: Current equity holder; Volastra Therapeutics: Consultancy, Other: Current equity holder, Research Funding; Johnson and Johnson: Research Funding; Eli Lilly: Research Funding; Janssen: Research Funding; Champions Oncology: Consultancy; Freenome: Consultancy, Other: Current equity holder in a privately-held company; One Three Biotech: Consultancy, Other: Current equity holder; AstraZeneca: Research Funding. Horwitz: Affimed: Research Funding; Aileron: Research Funding; ADC Therapeutics, Affimed, Aileron, Celgene, Daiichi Sankyo, Forty Seven, Inc., Kyowa Hakko Kirin, Millennium /Takeda, Seattle Genetics, Trillium Therapeutics, and Verastem/SecuraBio.: Consultancy, Research Funding; Acrotech Biopharma, Affimed, ADC Therapeutics, Astex, Merck, Portola Pharma, C4 Therapeutics, Celgene, Janssen, Kura Oncology, Kyowa Hakko Kirin, Myeloid Therapeutics, ONO Pharmaceuticals, Seattle Genetics, Shoreline Biosciences, Inc, Takeda, Trillium Th: Consultancy; Celgene: Research Funding; C4 Therapeutics: Consultancy; Crispr Therapeutics: Research Funding; Daiichi Sankyo: Research Funding; Forty Seven, Inc.: Research Funding; Kura Oncology: Consultancy; Kyowa Hakko Kirin: Consultancy, Research Funding; Millennium/Takeda: Research Funding; Myeloid Therapeutics: Consultancy; ONO Pharmaceuticals: Consultancy; Seattle Genetics: Consultancy, Research Funding; Secura Bio: Consultancy; Shoreline Biosciences, Inc.: Consultancy; Takeda: Consultancy; Trillium Therapeutics: Consultancy, Research Funding; Tubulis: Consultancy; Verastem/Securabio: Research Funding. DeSavi: Kymera Therapeutics: Current Employment, Current equity holder in publicly-traded company. Liu: Kymera Therapeutics: Current Employment, Current equity holder in publicly-traded company.

Peripheral T-Cell Lymphoma Involvement of the Central Nervous System: Impact of Novel Therapeutics on Clinical Outcomes

Primary Central Nervous System (CNS) involvement of peripheral T-cell lymphoma (PTCL) is a rare phenomenon, with a reported incidence ranging from 2% to 16.7%. Similarly, secondary CNS lymphoma with PTCL phenotype is rare, with an approximately 2-6% incidence. Both clinical situations lead to dismal outcomes. Given the rarity of CNS involvement with PTCL, our understanding of this clinical manifestation is limited to retrospective studies, which have identified risk factors for CNS involvement such as extranodal involvement, stage III-IV disease, bone marrow involvement as well as ATLL subtype. Herein, we characterize CNS involvement of PTCL over a 26-year time period at a single institution, identify if there are any factors that have a positive impact on survival, and extrapolate risk factors for CNS involvement from this dataset.From the years 1996-2020, 222 patients were diagnosed with PTCL, of those, 25 patients developed CNS involvement. All patients had secondary CNS involvement. Baseline characteristics including first-line therapy are noted in Table 1. Four patients received intrathecal methotrexate for CNS prophylaxis, all of which were patients with an ATLL diagnosis. The median time from initial diagnosis to CNS involvement was 4.77 months (0-64 months). Upon CNS diagnosis, the median time to death was 1.13 months. With a median of 2 lines of treatment (range 1-5), 12 patients were exposed to novel therapeutic agents (HDAC inhibitors [HDACis], brentuximab vedotin, pralatrexate) and/or clinical trials investigating epigenetic combinations. Of these patients, 10 patients were exposed to novel therapeutics and/or epigenetic based clinical trials in the 2 nd line setting. There was a trend towards improved overall survival with exposure to novel therapeutics and/or treatment on epigenetic based clinical trials (p=0.1) (Figure 1). With the majority of patients surviving <6 months from CNS diagnosis, there were three excellent responders that survived >12 months, all of which were exposed to novel therapeutics. Two of the three excellent responders were diagnosed with CNS involvement upon initial diagnosis, while 1 patient relapsed in the fourth-line setting with CNS involvement. All three of the excellent responders were exposed to novel therapeutics, particularly pralatrexate as a commonality in the second line setting. Using logistic regression, an ATLL diagnosis, extranodal involvement, and a high ECOG score were associated with a higher risk of CNS involvement. Unlike other studies, a high IPI score was not associated with a predilection for CNS involvement.In conclusion, we describe one of the largest single-center collection of CNS PTCL involvement. CNS involvement of PTCL is rare, with a reported cumulative incidence in this cohort of 11.3% over a 26-year time period. Risk factors that were identified include an ATLL diagnosis, extranodal involvement, and poor performance status. Exposure to novel therapeutics leads to a trend towards improved outcomes possibly secondary to improved disease control, but overall, the majority of patients had dismal outcomes. Notably, of the novel therapeutics interrogated, romidepsin and pralatrexate have low penetrance into the CNS, while there is no current evidence to suggest brentuximab vedotin is able to cross the blood-brain barrier. The possibility of a disturbed blood-brain barrier to permit improved penetrance of these drugs is plausible, but further studies are warranted to support this. Although a small percentage of patients will suffer from CNS PTCL, there is a dire need to improve therapy for this patient population and to establish universal metrics to identify patients that are at risk of CNS involvement. Moreover, given the rarity of CNS PTCL involvement, a future endeavor would be to validate these findings in larger, multicenter initiative. [Display omitted] DisclosuresLue: AstraZeneca: Speakers Bureau; Kymera Therapeutics: Research Funding; TG Therapeutics: Consultancy; Epizyme: Consultancy; Kura Oncology: Consultancy. Marchi: Astex: Research Funding; Kyowa Kirin: Honoraria; Merck: Research Funding; BMS: Research Funding; Myeloid Therapeutics: Honoraria; Kymera Therapeutics: Other: Scientific Advisor. O'Connor: Myeloid Therapeutics: Current equity holder in publicly-traded company, Honoraria, Membership on an entity's Board of Directors or advisory committees; Mundipharma: Honoraria; Servier: Research Funding; Kymera: Current equity holder in publicly-traded company, Honoraria, Membership on an entity's Board of Directors or advisory committees; Astex: Research Funding; BMS: Research Funding; Merck: Research Funding; TG Therapeutics: Current Employment, Current equity holder in publicly-traded company.

Manifestation of Large Granular Lymphocyte Leukemia in Pediatric and Young Adult Population Is Distinct from Older Adult Cohorts

Introduction: Large Granular Lymphocyte (LGL) leukemia is a rare lymphoproliferative disorder usually manifested in elderly individuals, with mean age of onset at 65. However, LGL leukemia cases in pediatric and young adult (age <30) populations are occasionally observed. Severity of disease, response to routine LGL treatments (methotrexate, cyclophosphamide, cyclosporine), and molecular profiling of this cohort is largely unknown, with only a few case reports describing the occurrence. Here we present the first comprehensive analysis of pediatric and young adult LGL leukemia patients, where we compare demographic and hematologic parameters, frequency of STAT3 mutations, whole exome and transcriptomic profile, and treatment responses to the older adult (age >50) cohort.Methods: We retrospectively collected clinical data from 23 young adult (age <30), 105 adult (age 30-50), and 89 older adult (age >50) LGL leukemia patients. All participants signed informed consent to provide biospecimens and clinical records to the LGL Leukemia Registry. Whole exome (PBMC and saliva) and RNA sequencing (PBMC) was conducted on 115 patients. Sanger sequencing was utilized to determine STAT3 mutational status in the remaining 102 patients.Results: STAT3 is the most frequently mutated gene in LGL leukemia, and the mutation is associated with lower absolute neutrophil counts (ANC). We observed no differences in the frequency of STAT3 somatic mutations in young adult, adult, and older adult LGL leukemia (p=0.143). However, we detected a significant positive linear relationship between age of the patient and ANC values (p=0.002) for STAT3 mutant patients (Figure 1A). STAT3 wild-type (WT) patients did not display this relationship (p=0.756). No age associated trends were detected for hemoglobin values, although we detected decreasing red blood cell (RBC) values with increasing age for both STAT3 mutated and WT patients (p= 0.031, 0.010, respectively). No difference in sex (male vs female) balance was found within the young adult cohort (p=0.190). As rheumatoid arthritis (RA) is observed in ~30% of LGL leukemia patients, we asked if this prevalence also holds in the younger cohort. RA was observed in similar proportion in all young, adult, and older adult groups (p=1).To compare the severity of disease manifestation between the age groups, we first asked how many patients ever initiated LGL-related treatments in each age group. We found that patients under 50 are more likely to be on LGL related treatments compared to patients over the age of 50 (p=0.016) (Figure 1B). Next, we examined length of survival between age groups. Despite increased initiation of LGL related treatments, no statistically significant difference in overall survival (OS) was observed between patients under 50 and patients over the age of 50 (p=0.33) (Figure 1C). Therefore, we asked if the treatment response in younger patients is better compared to older patients. We observed no statistically significant differences in the routine LGL treatment responses between patients under 50 and patients over the age of 50 (p=0.732).Interestingly, epigenetic and chromatin modifier mutations are equally common in patients 50 years old and under relative to older adult patients (p= 0.271) (Figure 1D). Transcriptomic analysis of the PBMC data revealed enrichment of TNFα signaling in patients older than 50, while IFNα and IFNγ signaling was enriched in patients 50 years old and younger.Conclusions: We report the clinical and molecular analysis of LGL leukemia in pediatric/young adult and adult patients compared to the older adult patients that comprise the majority of LGL cases. We show that while STAT3 mutation frequency is similar across all age groups, younger patients with STAT3 mutation show lower ANC values compared to older patients. Importantly, we show that younger patients exhibit a more severe disease, as indicated by increased initiation of LGL treatment. However, overall survival in younger groups compared to older patients is not impacted. Finally, we show that younger patients display similar proportions of epigenetic and chromatin modifying mutations that are a prominent feature of older patients, and feature enrichment of IFNα and IFNγ signaling distinct from older patients. [Display omitted] DisclosuresFeith: Kymera Therapeutics: Membership on an entity's Board of Directors or advisory committees. Loughran: Dren Bio: Membership on an entity's Board of Directors or advisory committees; Keystone Nano: Membership on an entity's Board of Directors or advisory committees; Bioniz Therapeutics: Membership on an entity's Board of Directors or advisory committees; Kymera Therapeutics: Membership on an entity's Board of Directors or advisory committees.

Tolinapant (ASTX660), a Non-Peptidomimetic Antagonist of cIAP1/2 and XIAP, and the HDAC Inhibitor Romidepsin Are Synergistic in in Vitro Models of T Cell Lymphoma

Background: The PTCL are a heterogeneous group of non-Hodgkin lymphomas originating from mature T-lymphocytes. They are aggressive diseases, often resistant to conventional chemotherapy. Despite the fact that a number of new agents have been approved, treatment paradigms tailored to the biology of the disease have yet to emerge. Tolinapant (ASTX660) is a potent antagonist of both cellular and X-linked inhibitors of apoptosis proteins (cIAP1/2 and XIAP), and is presently in phase I/II trials in patients with advanced solid tumors and lymphomas (NCT02503423). IAP antagonists enhance tumor necrosis factor (TNF) receptor superfamily mediated apoptosis (Ward GA, et al. Mol Cancer Ther. 2018), are potent anti-tumor immune enhancers and induce markers of immunogenic cell death such as damage associated molecular patterns (DAMPs; Ye W, et al, Oncoimmunology, 2020). Objectives: We explored the sensitivity of a range of T-cell lymphoma (TCL) cell lines to tolinapant. We establish the synergy coefficient between tolinapant and the HDAC inhibitor, romidepsin, and interrogated the molecular basis of their synergistic interaction. Methods: A panel of human T-cell lymphoma cell lines were tested in proliferation assays (CellTiterGlo) for sensitivity to tolinapant in the presence or absence of 10ng/ml of TNF alpha. For combination studies, with tolinapant and romidepsin, each drug was tested at the IC10 and IC40 concentrations in the presence or absence of TNF alpha. Synergy scores using the Excess over Bliss (EOB) model were calculated using SynergyFinder (Aleksandr Ianevski et al; Nucleic Acids Research, 2020). Additionally, the effects of tolinapant and romidepsin on the IAPs and caspases were analyzed by western blots. TNFR1 receptor expression and induction of DAMPs were also analyzed by flow cytometry. Results: TCL Lines demonstrated varying sensitivities to tolinapant in the presence or absence of TNF alpha. The most sensitive cell lines, ALK+ ALCL and SUP-M2, had IC50 concentrations ranging from 200nM ± 100nM to 20nM ± 1nM in the absence or presence of TNF alpha, respectively, at 24, 48 and 72hrs, while a resistant CTCL cell line HH had an IC50 concentration of over 20mM, even in the presence of TNF alpha. Interestingly, using western blot analysis, we found that the presence of TNF alpha increased the levels of cIAP1 in the tolinapant sensitive SUP-M2 cell line, but not in the resistant HH cell line. However, there was a concentration dependent decrease in cIAP1 but not in XIAP in both cell lines treated with tolinapant. Flow cytometry analysis demonstrated that tolinapant increases the expression of TNFR1 and DAMPs in a dose dependent manner on the sensitive SUP-M2, but not in the resistant HH cells. In combination experiments, using the EOB model, tolinapant plus romidepsin was found to be synergistic in the absence of TNF alpha, at 36hrs, in both the sensitive cell line SUP-M2 and the resistant cell line HH. In the presence of TNF alpha, synergism was seen only in the sensitive cell line SUP-M2 and antagonistic in the HH cell line (Fig. 3). In the tolinapant plus romidepsin treated samples, cIAP1 levels decreased in the SUP-M2 cell line, in the absence of TNF alpha, however, addition of TNF alpha did not alter the levels of cIAP1 in the SUP-M2 cells. The cIAP1 levels decreased in the HH cells treated with the combination, in both the presence or absence of TNF alpha (Figure). Our findings indicate that the synergy of the tolinapant plus romidepsin is not dependent on the presence of TNF alpha. Conclusion: Tolinapant has demonstrated potent cytotoxic effects against a broad range of TCL lines both as a monotherapy and in combination with the HDAC Inhibitor, romidepsin. In in vitro studies, T cell lymphoma cell lines demonstrated varying sensitivity to tolinapant with certain cell lines being more resistant, even in the presence of TNF alpha. Interestingly, the addition of romidepsin appeared to overcome the intrinsic resistance to tolinapant in the absence of TNF alpha. These data provide the rationale to continue to explore the combination of tolinapant and romidepsin in vivo and to investigate additional combinations with T-cell specific agents (e.g. pralatrexate, belinostat, azacitidine and decitabine). [Display omitted] DisclosuresSmyth: Astex Pharmaceuticals: Current Employment. Sims: Astex Pharmaceuticals: Current Employment. Loughran: Kymera Therapeutics: Membership on an entity's Board of Directors or advisory committees; Bioniz Therapeutics: Membership on an entity's Board of Directors or advisory committees; Keystone Nano: Membership on an entity's Board of Directors or advisory committees; Dren Bio: Membership on an entity's Board of Directors or advisory committees. Marchi: Kyowa Kirin: Honoraria; Myeloid Therapeutics: Honoraria; Astex: Research Funding; BMS: Research Funding; Merck: Research Funding; Kymera Therapeutics: Other: Scientific Advisor.

Influence of Treatment Facility Type and Annual Patient Volume on Overall Survival in Patients with Mantle Cell Lymphoma: A National Cancer Database Analysis

Influence of Treatment Facility Type and Annual Patient Volume on Overall Survival in Patients with Mantle Cell Lymphoma: A National Cancer Database Analysis

Neurotoxicity of Axicabtagene Ciloleucel and Long-Term Outcomes - in a Minority Rich, Ethnically Diverse Real World Cohort

IntroductionChimeric antigen receptor (CAR) T-cell therapy has revolutionized the treatment of B- cell malignancies leading to durable responses in patients with relapsed/refractory disease. 1,2 One of the most severe toxicities associated with this treatment is immune effector cell-associated neurotoxicity syndrome (ICANS), which was seen in 65-75% of patients treated with axicabtagene ciloleucel (axi-cel) in initial clinical trials. ICANS can range from mild headache to coma, and can occur with or without cytokine release syndrome (CRS). Due to the recent development of CAR T-cell therapy, the long-term effects of ICANS are unknown. This study sought to determine the long-term outcomes in patients with neurotoxicity from axi-cel.MethodsWe conducted a retrospective chart review of patients who received CAR T-cell therapy with axi-cel between June 2018 and June 2021. Neurotoxicity was graded according to the American Society for Transplantation and Cellular Therapy (ASTCT) ICANS grading system. 3 The primary outcome was percentage of patients who had neurotoxicity defined as ICANS grade ≥ 1 as well as the percentage of patients with neurotoxicity lasting ≥ 1 month. We captured descriptive data such as age, sex, ethnicity, comorbidities, IPI score, stage, baseline neurologic dysfunction, performance status, and number of prior treatments. Secondary outcomes included progression free survival (PFS) and overall survival (OS).ResultsThirty-four patients received axi-cel between June 2018 and June 2021 at our institution. Median age of patients was 65. Twenty patients (59%) were male and 14 (41%) were female. The majority of patients received axi-cel for diffuse large B-cell lymphoma (97%). Study population was predominantly hispanic (35%), white (32%), African american (29%) and asian (3%). (Sixteen patients (47%) developed neurotoxicity of any grade, with 7 patients (21%) ≥ grade 3. Of note, 4 patients (12%) died during admission for CAR T-cell therapy and 3/4 deaths were in patients with ICANS ≥ grade 3. Median follow up time was 8 months. Of the 12 patients with neurotoxicity who survived initial admission for CAR-T, 9 (75%) patients recovered from neurotoxicity and mental status was at baseline at discharge without recurrence during follow up. Three (25%) of patients had prolonged neurotoxicity lasting > 1 month. Long-term neurotoxicity included confusion, disorientation,and mild cognitive impairment in the three patients. One patient recovered 15 months after CAR T-cell infusion. 2 patients had prolonged neurotoxicity resulting in deterioration of functional status and death in 1 patient, and 1 patient transitioning to hospice and being lost to follow up.ConclusionsNeurotoxicity from axicabtagene ciloleucel is a common adverse event, with half of patients in our cohort having neurotoxicity of some degree, and 20% ≥ grade 3. Twenty-five percent of patients that developed neurotoxicity had long-term effects lasting > 1 month, which resulted in deterioration of functional status in 2 patients. Long-term neurotoxicity included disorientation, confusion, and memory impairment. Our study is limited by a small sample size. Larger studies with longer follow-up times are needed to further characterize the long-term outcomes of neurotoxicity associated with CAR T-cell therapy. Neurotoxicity can be confounded by other causes of neurological dysfunction in these patients such as hospital delirium, chemotherapy toxicity, encephalopathy from infection, and subtle baseline neurologic dysfunction that may not be apparent at presentation. Next steps include prospective evaluation of patients with formal neurology evaluation prior to CAR T-cell therapy and periodically after treatment, in order to objectively monitor late neurologic effects of CAR T-cell therapy.1. Fl, L. et al. Long-term safety and activity of axicabtagene ciloleucel in refractory large B-cell lymphoma (ZUMA-1): a single-arm, multicentre, phase 1-2 trial. Lancet Oncol. 20, (2019).2. Jacobson, C. Primary Analysis of Zuma-5: A Phase 2 Study of Axicabtagene Ciloleucel (Axi-Cel) in Patients with Relapsed/Refractory (R/R) Indolent Non-Hodgkin Lymphoma (iNHL). in (ASH, 2020).3. Dw, L. et al. ASTCT Consensus Grading for Cytokine Release Syndrome and Neurologic Toxicity Associated with Immune Effector Cells. Biol. Blood Marrow Transplant. J. Am. Soc. Blood Marrow Transplant. 25, (2019). DisclosuresGritsman: iOnctura: Research Funding. Shastri: Onclive: Honoraria; Guidepoint: Consultancy; GLC: Consultancy; Kymera Therapeutics: Research Funding. Verma: Celgene: Consultancy; BMS: Research Funding; Stelexis: Current equity holder in publicly-traded company; Curis: Research Funding; Eli Lilly: Research Funding; Medpacto: Research Funding; Novartis: Consultancy; Acceleron: Consultancy; Stelexis: Consultancy, Current equity holder in publicly-traded company; Incyte: Research Funding; GSK: Research Funding; Throws Exception: Current equity holder in publicly-traded company.

Utilizing Organ-Sparing Marrow Irradiation to Condition Patients Prior to Allogeneic Hematopoietic Cell Transplant with High-Risk Hematologic Malignancies: Results of a Pilot Study

Background: Total body irradiation (TBI) has long been incorporated as part of the conditioning regimen prior to hematopoietic stem cell transplant (HSCT). While the myeloablative TBI conditioning is associated with a lower relapse rate in high risk diseases such as Acute Myeloid Leukemia (AML), Myelodysplastic Syndrome (MDS), and Acute Lymphoblastic Leukemia (ALL), it is also associated with substantial toxicities, and increased NRM so use of this regimen is limited to young patients with excellent performance status. In this study, we used a linac-based volumetric modulated arc therapy (VMAT) technique to deliver standard myeloablative radiation to high risk body sites while sparing radiation sensitive organs (Organ Sparing Marrow Targeted Irradiation, OSMI). We hypothesized that this technique would be feasible and safe in patients who are older or who have higher transplant specific comorbidity index (HCT-CI), typically ineligible for standard TBI conditioning.Methods: This is a single-arm prospective study. Patients from age 18-75 with high risk AML, MDS or ALL were eligible. There are 3 cohorts: (1) age 18-50 with HCT-CI of 3/4; (2) age 51-65 with HCT-CI of ≤ 3; and (3) age 66-75 with HCT-CI of ≤ 2. Patients receive OSMI to a total dose of 1200 cGy delivered twice daily for 6 fractions for a total of 7200 cGy. Clinical tumor volume includes total skeletal bone marrow and any sanctuary or high-risk areas. Graft-versus-host disease (GVHD) prophylaxis originally was tacrolimus and methotrexate. Given high incidence of bacterial infections related to mucositis, prophylaxis was changed to tacrolimus and sirolimus without methotrexate. All patients received Keratinocyte growth factor for prevention of mucositis. The primary objective was to assess feasibility and tolerability of OSMI based HSCT as defined by transplant-related mortality (TRM) at day 30 (D30) as well as rate of grade II/III organ toxicity (defined by Bearman Regimen-Related Toxicities Scale) attributable to conditioning occurring within 30 days.Results: Patient demographics for the 24 patients are shown in Table 1. Median age of recipients was 56.5 years. No graft failures were observed. The most common grade II or III Bearman toxicities include mucositis (grade 2: n=4), and diarrhea (grade 2: n=4). Clinical outcomes are shown in Figure 2. With a median follow-up of 3.3 years, overall survival (OS) and relapse-free survival (RFS) at 2 years was 78% and 74% respectively. Among the 5 patients who were not in complete remission at the time of transplant, 2-year OS and RFS rate was 40%. Incidence of Grades II-IV acute GVHD was 79% and Grades III-IV GVHD was 30%. Relapse incidence was 4% at 2 years. Incidence of Thrombotic microangiopathy by day 100 (TMA) as defined by Jodele's criteria was 17%. Incidence of chronic GVHD was 45% and severe chronic GVHD was 16%. One year non-relapse mortality was 22%, likely due to higher incidence of GVHD.Conclusions: Selected patients who are older or with higher HCT-CI, who are typically not candidates for standard TBI conditioning, were able to receive a radiation-based myeloablative conditioning regimen with 2 year overall survival rates of 78%. We observed a high incidence of TMA, possibly related to use of tacrolimus and sirolimus as GVHD prophylaxis, and a high incidence of Grade II-IV acute GVHD. Low incidence of relapse was observed. OSMI-based conditioning was feasible in this cohort with median age of 56 years and was associated with low rates of relapse and favorable 2 year overall survival. [Display omitted] DisclosuresVasu: Boehringer Ingelheim: Other: Travel support; Seattle Genetics: Other: travel support; Kiadis, Inc.: Research Funding; Omeros, Inc.: Membership on an entity's Board of Directors or advisory committees. Jaglowski: Novartis: Consultancy, Research Funding; Takeda: Consultancy; Juno: Consultancy; Kite, a Gilead Company: Consultancy, Research Funding; CRISPR Therapeutics: Consultancy. Brammer: Seattle Genetics: Speakers Bureau; Celgene: Research Funding; Kymera Therapeutics: Consultancy. de Lima: Incyte: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Miltenyi Biotec: Research Funding.

Predictors of Central Nervous System (CNS) Involvement in North American Adult T-Cell Leukemia Lymphoma (ATLL) and Their Survival Pattern

▪Introduction:North American-ATLL (NA-ATLL) is a distinct genomic and clinical entity when compared with Japanese ATLL. Despite the frequent CNS involvement by this entity there are no prognostication tools to identify variables associated with higher risk. We studied one of the largest NA-ATLL cohorts in the United States at a minority rich ethnically diverse New York City based tertiary care center to identify discrete variables that may be associated with CNS involvement. Additionally, we examined the predictive power of the previously validated International Prognostic Index (IPI) developed for Diffuse Large B-cell Lymphoma (DLBCL) in terms of CNS involvement as well as overall survival in our cohort.In our previous work, we assigned CNS involvement of ATLL if: 1) cerebrospinal fluid (CSF) cytology or flow cytometry was positive; 2) CNS imaging was positive for disease involvement or 3) physical exam was compatible with neurologic involvement.Methods and results:Of 65 NA-ATLL patients (pts), 20 (30.77%) had CNS involvement by ATLL meeting above mentioned criteria. The median age of all pts in our dataset was 59 years. Pts were divided into non- CNS involved NA-ATLL (non-CNS NA-ATLL) and CNS involved NA-ATLL (CNS NA-ATLL) groups. Parameters to predict CNS involvement were outlined as leukocytosis (>11000 per microliter [μL]), elevated acute lymphocytic count (>4000/ μL), elevated lactate dehydrogenase (LDH) (>190 units/liter [u/l]), generalized lymphadenopathy (LAD) defined as involvement of 2 or more non-contiguous nodal sites, elevated corrected serum calcium levels (>10.5 mg/deciliter), bone marrow (bm) involvement and serosal involvement defined as pleural or peritoneal involvement. These variables were chosen given our prior work identifying them as critical to predict OS in our general NA-ATLL population.We then performed the Fisher test of proportions to determine if the variables above mentioned were different between the CNS NA-ATLL and the non-CNS NA-ATLL. We did not find significant associations when analyzing gender (p=0.0535), leukocytosis (p= 0.4001), lymphocytosis (p =0.57), hypercalcemia (p= 0.7661), elevated LDH (p= 0.4898), generalized LAD (p=0.271), serosal involvement (p= 0.05088) or bone marrow involvement (p=1). We only found a strong association when examining ATLL subtypes, being the acute/lymphomatous variant strongly associated with CNS involvement (p=2.226e10 -5).To identify variables that can have an impact in OS in CNS NA-ATLL vs non-CNS NA-ATLL we calculated Kaplan Meier survival curves. We did not find any difference based on age (p=0.23), gender (p=0.95), leukocytosis (p= 0.074), lymphocytosis (p =0.21), hypercalcemia (p= 0.094), elevated LDH (p= 0.37), generalized LAD (p=0.28), and serosal involvement (p= 0.1) in the overall survival. The only significant association we found was bone marrow involvement in predicting poor OS in CNS NA-ATLL group (p= 0.038).Next, we determined IPI scores (age>60, ECOG performance status>2, Ann Arbor stage III/IV, serum LDH score >190 u/L and more than 1 extra-nodal site) in our CNS NA ATLL and non-CNS NA ATLL cohorts. We sought to determine if: 1) this prognostication tool is predictive in NA-ATLL and 2) if these variables can be used to identify CNS involvement in our cohort.CNS pts with a higher IPI score (>3) showed tendency towards a lower survival rate (p=0.089) than non-CNS pts (p=0.3). IPI score of 3 or more was not predictive of CNS involvement in our sample (p=1).Conclusions:NA-ATLL is a rare and protean disease with poor prognosis and CNS involvement is prevalent. With the variables used we did not find clear predictors of CNS associated disease other than patients presented with the lymphomatous and acute subtypes. We also observed than bone marrow involvement portends a dismal prognosis for individuals with CNS involvement. Future studies with a larger cohort could provider further insight on discovering predictors for CNS involvement in NA ATLL. [Display omitted] DisclosuresShah: Celgene/BMS: Research Funding; Janssen: Research Funding. Gritsman: iOnctura: Research Funding. Shastri: GLC: Consultancy; Kymera Therapeutics: Research Funding; Guidepoint: Consultancy; Onclive: Honoraria. Verma: BMS: Research Funding; GSK: Research Funding; Incyte: Research Funding; Medpacto: Research Funding; Curis: Research Funding; Eli Lilly: Research Funding; Stelexis: Consultancy, Current equity holder in publicly-traded company; Novartis: Consultancy; Acceleron: Consultancy; Celgene: Consultancy; Stelexis: Current equity holder in publicly-traded company; Throws Exception: Current equity holder in publicly-traded company. Janakiram: Amgen: Honoraria.

Effect of Age on Outcomes of Allogeneic Transplantation in Patients with Acute Myeloid Leukemia and Myelodysplastic Syndrome

Background: Allogeneic stem cell transplantation (allo-SCT) has become an increasingly important consolidation treatment option for patients with acute myeloid leukemia (AML) and as upfront therapy for patients with high-risk myelodysplastic syndrome (MDS). Although the median age at diagnosis for both diseases is above 65 years, studies evaluating allo-SCT as treatment option for patients aged 65 years or older are limited. Further, as the population ages, the number of patients above 65 years considered for allo-SCT will continue to rise. Thus, the aim of our current investigation was to analyze outcomes based on age in AML/MDS patients <65 years old and ≥65 years old who received allo-SCT at the Ohio State University.Methods: A retrospective analysis was performed for all AML/MDS patients who received allo-SCT between January 1984 and December 2018 at our institution. Primary endpoints included progression free survival (PFS) and overall survival (OS). PFS was counted from the day of transplantation to relapse or death. OS was defined as survival from the day of allo-SCT until death from any cause, with censoring of patients known to be alive at the time of last follow-up. PFS and OS were calculated using Kaplan Meier Curves. Secondary endpoints included cumulative incidences of grade II-IV and III-IV acute GVHD (aGVHD), chronic GVHD (cGVHD), relapse, and non-relapse mortality (NRM). Cumulative incidence rates of aGVHD, cGVHD, relapse, NRM were estimated and compared using Gray's test accounting for competing risks.Results: The cohort consisted of 900 AML/MDS patients, with 150 patients ≥65 years and 750 patients <65 years. The median age at transplant for the <65 years group was 49 years (range: 18-64 years) and 68 years (range: 65-76 years) for the ≥65 years group. Gender, race, Karnofsky score, and comorbidity index were similar between the two groups. A higher proportion of patients received myeloablative (MA) conditioning (65.1%) in the <65 years of age compared to 20% in the ≥65 years of age (p<0.01). A higher proportion of older patients had matched unrelated donors (57.3%), and reduced intensity conditioning (RIC) regimens (80%).The median time from diagnosis to transplantation was 176 days (range: 55-4920) for age <65 years and 168 days (range: 34-6079 days) for age ≥65 years. Median follow-up from allo-SCT was 5.9 years (range 0.8-35.9 years) and 3.4 years (range: 1.0-9.6 years) from transplantation among survivors. Neutrophil and platelet engraftment were similar among the groups (p=0.35; 0.11). 3 year OS of 42.3% (95% CI: 38.7-45.8%) and PFS of 38.3% (95% CI: 34.8%-41.9%) were observed for age <65 years. The corresponding OS and PFS for age ≥65 years was 46.3% (95% CI: 37.9%-54.3%) and 43.0% (95% CI: 34.7%-51.0%), respectively (Figure 1a & 1b). Cumulative incidences of relapse at 1 year in <65 and ≥65 years were 26.4% and 25.3%, respectively (p=0.43). The cumulative incidence of NRM at 1 year in <65 and ≥65 years was 23.2% and 17.3%, respectively (p=0.12; Figures 1c and d). The incidences of acute and chronic GVHD were similar in the two age groups. The cumulative incidence of aGVHD at day 100 in <65 and ≥65 years was 40.3% (95% CI: 36.4%-44.2%) and 43.0% (95% CI: 34.9%-50.7%), respectively. The cumulative incidence of cGVHD at day 365 in <65 and ≥65 years was 40.8% (95% CI: 36.9%-44.6%) and 41.6% (95% CI: 33.6%-49.4%), respectively.Conclusion: Overall, our study suggests similar outcomes for elderly patients undergoing allo-HCT as compared to their counterparts, which is in line with prior studies. This likely is due to advancements in the transplant field, including the development of RIC and alternative donors, which have allowed greater access to transplant for older adults. Utilization of allo-HCT is feasible and should be considered for AML/MDS patients ≥65 years. Further research is underway to evaluate the important determinants of health status in older patients undergoing allo-HCT and to ultimately help predict NRM (BMT CTN 1704). [Display omitted] DisclosuresBumma: Amgen, Sanofi: Speakers Bureau; Janssen, Oncopeptides, Sanofi: Consultancy. Vasu: Seattle Genetics: Other: travel support; Boehringer Ingelheim: Other: Travel support; Kiadis, Inc.: Research Funding; Omeros, Inc.: Membership on an entity's Board of Directors or advisory committees. Jaglowski: Takeda: Consultancy; Juno: Consultancy; Kite, a Gilead Company: Consultancy, Research Funding; CRISPR Therapeutics: Consultancy; Novartis: Consultancy, Research Funding. Mims: Syndax Pharmaceuticals: Consultancy; BMS: Consultancy; Jazz Pharmaceuticals: Consultancy; Abbvie: Consultancy; Genentech: Consultancy; Kura Oncology: Consultancy; Leukemia and Lymphoma Society: Consultancy; Glycomemetics: Research Funding; Aptevo: Research Funding; Xencor: Research Funding; Daiichi-Saynko: Consultancy. Brammer: Celgene: Research Funding; Seattle Genetics: Speakers Bureau; Kymera Therapeutics: Consultancy. Saad: Incyte Pharmaceuticals: Consultancy; careDx: Consultancy; Amgen: Research Funding; Kadmon: Research Funding; OrcaBio: Research Funding; Magenta Therapeutics: Consultancy. de Lima: Miltenyi Biotec: Research Funding; Incyte: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees.

Romidepsin in Conditioning and Maintenance Mitigates Relapse Risk and Enhances NK-Cell Cytotoxicity in Patients Receiving Allogeneic Stem Cell Transplant for Aggressive T-Cell Malignancies: Results of a Phase I/II Clinical Trial

Romidepsin in Conditioning and Maintenance Mitigates Relapse Risk and Enhances NK-Cell Cytotoxicity in Patients Receiving Allogeneic Stem Cell Transplant for Aggressive T-Cell Malignancies: Results of a Phase I/II Clinical Trial

Phase II Study of Venetoclax in Combination with Obinutuzumab and Bendamustine in Patients with High Tumor Burden Follicular Lymphoma As Front Line Therapy (PrECOG 0403)

Phase II Study of Venetoclax in Combination with Obinutuzumab and Bendamustine in Patients with High Tumor Burden Follicular Lymphoma As Front Line Therapy (PrECOG 0403)

Synergistic Role of Leukemic and Non-Leukemic Immune Repertoires in CD8+ T-Cell Large Granular Lymphocytic Leukemia As Identified By Single-Cell Transcriptomics

Background: T-cell large granular lymphocytic leukemia (T-LGLL), a rare lymphoproliferative disorder of mature T cells, is characterized by the accumulation of activated effector T cells leading to a clonally restricted T-cell receptor (TCR) repertoire. Chronic antigen stimulation together with activating somatic STAT3 mutations have been proposed to lead to clonal expansion of leukemic cells. However, no holistic research has been done to show how leukemic and non-leukemic cells liaise to sustain abnormal immune reactivity in T-LGLL.Methods: We investigated the transcriptome and TCR repertoire in T-LGLL using: 1) single-cell RNA and TCR (scRNA+TCRαβ) sequencing from CD45+ sorted blood cells (T-LGLL n=11, healthy n=6), 2) TCRβ sequencing from blood mononuclear cells (T-LGLL n=48, healthy n=823), 3) bulk RNA sequencing (T-LGLL n=15, healthy n=5), 4) plasma cytokine profiling (T-LGLL n=9, healthy n=9), and 5) flow cytometry validations (T-LGLL n=6, healthy n=6) (Figure)Results: ScRNA+TCRαβ-seq data revealed that in healthy controls, hyperexpanded CD8+ T-cell clones (at least 10 cells with identical TCRs) preferentially had an effector memory phenotype, whereas in T-LGLL, the hyperexpanded clonotypes represented a more cytotoxic (increased expression of GZMB, PRF1, KLRB1) and exhausted (LAG3 and TIGIT) phenotype. Using flow cytometry, we confirmed that upon anti-CD3/CD28/CD49 antibody stimulation, T-LGLL clones (CD8+CD57+) expressed higher levels of cytotoxic proteins (GZMA /GZMB , PRF1) but were deficient in degranulation responses and cytokine secretion as measured by expression of CD107a/b and TNFα/IFNγ, respectively.Focused re-clustering of the extracted T-LGLL clones from the scRNA+TCRαβ-seq data revealed considerable heterogeneity among the T-LGLL clones and partly separated the mutated (mt) STAT3 and wild type (wt) STAT3 clones. STAT3wt clones upregulated T-cell activation and TCR signaling pathways, with a higher cytotoxicity and lower exhaustion score as compared to STAT3mt clones. This was validated with bulk RNA-seq data.To understand the antigen specificities of the T-LGLL clones, we combined previously profiled T-LGLL TCRs with our data to form the largest described dataset of 200 T-LGLL clones from 170 patients. Notably, T-LGLL clones were found to be private to each patient. Furthermore, the analysis by GLIPH2 algorithm grouping TCRs did not reveal detectable structural similarities, suggesting the absence of a unifying antigen in T-LGLL. However, in 67% of T-LGLL patients, the TCRs of leukemic clones shared amino acid level similarities with the rest of the non-leukemic TCR repertoire suggesting that the clonal and non-clonal immune repertoires are connected via common target antigens.To analyze the non-clonal immune repertoire in T-LGLL in detail, we compared our data to other published scRNAseq data from solid tumors (n=4) and hematologic cancers (n=8) and healthy controls (n=6). The analysis revealed that in T-LGLL also the non-leukemic CD8+ and CD4+ T cells were more mature, cytotoxic, and clonally restricted. When compared to healthy controls and other cancer patients, in non-leukemic T-LGLL the most upregulated pathway was IFNγ response.Finally, most of the upregulated cytokines in T-LGLL (e.g., CCL2/3/7, CXCL10/11, IL15RA) were secreted predominantly by monocytes and dendritic cells, which also had upregulated HLA class II expression and enhanced scavenging potential in T-LGLL patients. Ligand-receptor analysis with CellPhoneDB revealed that the number of predicted cell-cell interactions was significantly higher in T-LGLL as compared to reactive T-cell clones in healthy controls. The most co-stimulatory interactions (e.g., CD2-CD58, TNFSF14-TNFRSF14) occurred between the IFNγ secreting T-LGLL clones and the pro-inflammatory cytokine secreting monocytes.Conclusions: Our study shows a synergistic interplay between the leukemic and non-leukemic immune cell repertoires in T-LGLL, where an aberrant antigen-driven immune response including hyperexpanded CD8+ T-LGLL cells, non-leukemic CD8+ cells, CD4+ cells, and monocytes contribute to the persistence of the T-LGLL clones. Our results provide a rationale to prioritize therapies that target the entire immune repertoire and not only the T-LGLL clones in patients with T-LGLL. [Display omitted] DisclosuresLoughran: Kymera Therapeutics: Membership on an entity's Board of Directors or advisory committees; Bioniz Therapeutics: Membership on an entity's Board of Directors or advisory committees; Keystone Nano: Membership on an entity's Board of Directors or advisory committees; Dren Bio: Membership on an entity's Board of Directors or advisory committees. Maciejewski: Alexion: Consultancy; Novartis: Consultancy; Regeneron: Consultancy; Bristol Myers Squibb/Celgene: Consultancy. Mustjoki: Novartis: Research Funding; BMS: Research Funding; Janpix: Research Funding; Pfizer: Research Funding.

Seroconversion Rates after COVID-19 Vaccination Amongst Patients with Hematologic Malignancies: Results of a Rapid Vaccination and Evaluation Program in a Minority Rich, Ethnically Diverse Inner City Cohort

Seroconversion Rates after COVID-19 Vaccination Amongst Patients with Hematologic Malignancies: Results of a Rapid Vaccination and Evaluation Program in a Minority Rich, Ethnically Diverse Inner City Cohort

Efficient Targeting of CD38 in Mature T-Cell Neoplasms with Daratumumab and Allogeneic NK Cells

Introduction: Mature T-cell neoplasms (MTCN) are a heterogeneous and aggressive group of lymphoid neoplasms with very limited options for precision immunotherapy. Targeted immunotherapy with antibodies directed against surface markers on tumor cells has emerged as an effective treatment for B-cell neoplasms, but the development of immunotherapy strategies for MTCN has been much slower. CD38 is expressed at low levels in a subset of normal resting T-cells. Data on the frequency and level of CD38 expression is MTCN are lacking. Our goal was to study the expression and stability of CD38 on a spectrum of neoplastic T-cell populations and assess the potential anti-tumor effect of anti-CD38 monoclonal antibodies in combination with allogeneic natural killer (NK) cells in MTCN.Methods and results: We searched the Thomas Jefferson University Hospital (TJUH) pathology records for all cases of MTCN for which immune-phenotypical characterization of the neoplastic T-cell population by multi-color flow cytometry (FC) was available. CD38 expression was evaluated in cases where an abnormal T-cell population (defined as loss of one on more pan T-cell markers and/or a skewed CD4 to CD8 ratio). A total of 103 unique patients with MTCN were identified. Of these, 51 had at least one biopsy whereby tumor cells had an abnormal immunophenotype which could then be assessed for CD38 expression. CD38 was expressed to some extent in all but 2 cases with expression levels on peripheral T-cell lymphoma-not other specified (PTCL-NOS)(% Mean±SEM = 80.84±10.26, N=11), angioimmunoblastic T-cell lymphoma (AITL) (% Mean±SEM = 80.56±7.34, N=6), nodal PTCL with T follicular-helper (T FH) phenotype (% Mean±SEM = 55.00±12.72, N=7), anaplastic large cell lymphoma (ALCL) (% Mean±SEM = 77.38±10.75, N=3), large granular lymphocytic leukemia (LGLL) (% Mean±SEM = 80.27±7.49, N=4), T-cell prolymphocytic leukemia (T-PLL) (% Mean±SEM = 88.26±4.20, N=7), cutaneous T-cell lymphoma (CTCL) (% Mean±SEM = 49.52±14.77, N=7), adult T‐cell leukemia/lymphoma (ATLL) (% Mean±SEM = 76.68±10.45, N=3), hepatosplenic T-cell lymphoma/monomorphic epitheliotropic intestinal T-cell lymphoma (HSTCL/MEITL) (% Mean±SEM = 75.00±11.37, N=3). The medians and ranges of the MFI of CD38 on CD38+ tumor cells were the following: PTCL-NOS 29.46 (3.1-115.62), AITL 13.64 (2.67-29.41), other PTCL-T FH 5.87 (0-48.67), ALCL 11.13 (3.6-11.28), LGL (13.52 (9.72-18.25), T-PLL 6.49 (3.09-18), CTCL 8.36 (0-116.75), ATLL 27.17 (3.54-60.5), HSTCL/MEITL 15.96 (6.96-167.85). We also measured surface expression of CD38 on the patient-derived MTCN cell lines HuT-78, HuT-102, Jurkat, H9, HH, and MOTN1, all of which expressed CD38, to determine which of these cell lines could be used for in vitro experiments. We next evaluated if the CD38 molecule is an effective target for antibody-mediated therapy in MTCN, by testing the ability of daratumumab (dara) to enhance antibody-dependent cellular cytotoxicity (ADCC) elicited by NK cells. For this, we purified normal NK-cells from TJUH Blood Bank leukoreduction filters and cultured with recombinant IL-15 for 48 hours prior to all experiment. T-cell lines and primary MTCN cells were treated with increasing concentrations (0.1 µg/mL - 2 µg/mL) of dara or isotype control. NK-cells were added at Effector:Target ratio of 5:1 and incubated for 4 hours at 37⁰ Celsius. Cytotoxicity was measured by LDH release assay. Dara induced significant cell lysis starting at doses as low as 0.1μg/mL in both T-cell lines and primary MTCN cells, reaching maximum cytotoxicity at 0.5-2μg/mL (mean±SEM cytotoxicity in isotype vs dara treated cells= 50.0±5.05% vs 97.5±2.5%, N=4, p-value=0.0002). The degree of ADCC induction also correlated with interferon-gamma (IFN-g) release by NK cells in vitro for both T-cell lines and primary MTCN cells.Conclusions: The majority of MTCN analyzed (N=49, 96%) showed any degree of CD38 expression by FC with a wide variation of intensity, including within the same subtype. Allogeneic NK cells efficiently elicited dara-mediated ADCC of tumor cells from all MTCN subtypes and produced abundant IFN-g. These data highlight the potential of targeting CD38 in MTCN with anti-CD38 antibodies and allogeneic NK cells. The strong CD38 expression observed in most tumor cells from ultra-rare and very aggressive subtypes of MTCL opens the door to much needed new treatment strategies. DisclosuresBrammer: Celgene: Research Funding; Kymera Therapeutics: Consultancy; Seattle Genetics: Speakers Bureau. Chakravarti: Kiadis Pharma: Patents & Royalties. Porcu: Viracta: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Innate Pharma: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BeiGene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Incyte: Research Funding; Daiichi: Honoraria, Research Funding; Kiowa: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Spectrum: Consultancy; DrenBio: Consultancy.

Equal Access to Hematopoietic Stem Cell Transplant in a Minority-Rich, Ethnically Diverse, Socioeconomically Disadvantaged Population with Peripheral T-Cell Lymphomas at the Montefiore Medical Center/Albert Einstein College of Medicine

Introduction:Peripheral T-cell lymphomas (PTCLs) are rare and heterogeneous with poor prognosis. There is a paucity of data on outcomes in minority populations. We studied relationships between socioeconomic status (SES), race, and ethnicity and access to hematopoietic stem cell transplant (HSCT) and survival. For analyses of SES we used a measure of neighborhood disadvantage called the Area Deprivation Index (ADI), a composite of 17 measures of education, employment, housing quality, and poverty validated across a range of diseases (Kind et al NEJM 2018).Methods:To identify subjects with PTCL, we used SQL to query our Enterprise Data Warehouse for ICD 10 codes C84 and C91.5. We used medical record numbers for chart review and recorded the following in Excel: WHO 2016 PTCL classification (Swerdlow et al 2016 Blood), sex, race, ethnicity, address, date of birth, date of death/last contact, stem cell source (autologous [auto] vs. allogeneic [allo]), donor sources for allo (matched related [MRD], matched unrelated [MUD], haploidentical [haplo], or syngeneic), conditioning regimen, and date of stem cell infusion (HSCT D0). ADIs were obtained by geocoding subjects' addresses using an online tool (https://geocoding.geo.census.gov/) and matching census block groups to ADI 2019 national percentiles. Conditioning intensity was determined by the Center for International Blood and Bone Marrow Transplant Research operational definition (Giralt et al 2009). For survival analyses, subjects with more than 1 histology were analyzed according to that at HSCT D0. For subjects who underwent auto with subsequent allo, analyses were carried out on the allo. When there was an interval between last date known alive and first date known to have died, death was assumed at the end of the interval. Overall survival (OS) probabilities were estimated using the Kaplan-Meier method. Python, pandas, Matplotlib, and lifelines were used for data analysis and visualization.Results:We identified 407 patients with PTCL, of which 48 underwent HSCT between 9/19/2006 and 4/5/2021 - 22 autos and 26 allos. Data on access to HSCT are summarized in Figure 1 and Table 1. There was not a significant relationship between ADI or ethnicity and access to HSCT. The relationship between race and access to HSCT was significant (p = 0.024). Baseline characteristics of the HSCT cohort are summarized in Tables 2 and 3. Notably, 12/26 allos had adult T-cell leukemia/lymphoma (ATLL). Looking at survival by type of HSCT (Figure 2, Table 4), autos had median OS not reached. Autos' 2 and 4-year OS probabilities were both 81.57%, whereas these were both 40.49% for allos (p = 0.03 for 2 year and 4 year OS). No differences were observed in survival by ADI among autos or allos (Figure 3, Table 5). There was no statistically significant association between race and survival by the log rank test (Figure 4, Table 6). P-values could not be calculated for autos' 2 or 4-year OS. Among allos, p-values suggested a statistical difference in 2 and 4-year OS between white subjects (n = 1) and black/African American (AA) as well as other subjects.Finally, examining survival by ethnicity, no significant differences were seen between Hispanics and Non-Hispanics (Figure 5, Table 7).Conclusions:In our inner-city, minority-rich PTCL cohort, neighborhood disadvantage and ethnicity did not preclude access to HSCT. The autologous transplant survival curve with median OS not reached (longest survivor 14.71 years) indicates that our patients did have optimal, potentially curative outcomes. Although our sample size is small our population is predominantly inclusive of ethnic minorities and low SES. Analyzing larger datasets of ethnically and socioeconomically diverse individuals can provide further insight into HSCT access and outcomes. [Display omitted] DisclosuresGritsman: iOnctura: Research Funding. Shastri: Onclive: Honoraria; GLC: Consultancy; Kymera Therapeutics: Research Funding; Guidepoint: Consultancy. Verma: Acceleron: Consultancy; Novartis: Consultancy; Stelexis: Consultancy, Current equity holder in publicly-traded company; Eli Lilly: Research Funding; Curis: Research Funding; Medpacto: Research Funding; Incyte: Research Funding; GSK: Research Funding; BMS: Research Funding; Celgene: Consultancy; Stelexis: Current equity holder in publicly-traded company; Throws Exception: Current equity holder in publicly-traded company.

Completed Induction Phase Analysis of Magnify: Phase 3b Study of Lenalidomide + Rituximab (R 2) Followed By Maintenance in Relapsed/Refractory Indolent Non-Hodgkin Lymphoma

Completed Induction Phase Analysis of Magnify: Phase 3b Study of Lenalidomide + Rituximab (R 2) Followed By Maintenance in Relapsed/Refractory Indolent Non-Hodgkin Lymphoma

Brentuximab Vedotin Plus Cyclophosphamide, Doxorubicin, Etoposide, and Prednisone (CHEP-BV) Followed By BV Consolidation in Patients with CD30-Expressing Peripheral T-Cell Lymphomas

Brentuximab Vedotin Plus Cyclophosphamide, Doxorubicin, Etoposide, and Prednisone (CHEP-BV) Followed By BV Consolidation in Patients with CD30-Expressing Peripheral T-Cell Lymphomas