Citations

Introduction: Telomere biology disorders (TBD) are multisystemic accelerated aging syndromes due to abnormal telomere length (TL) shortening and increased cancer risk. Pediatric-onset TBD is characterized by severely shortened TL and specific associations with germline pathogenic variants mainly in DKC1, TINF2, PARN genes and characteristic clinical features [bone marrow failure (BMF), abnormal nail/skin/oral mucosa]. Adult-onset TBD is genetically distinct (predominantly, TERT, TERC, and RTEL1 mutations) with varied organ involvement [interstitial lung disease (ILD), BMF, cirrhosis, or bone disease] and heterogenous outcomes. In our previous study of predominantly adult patients with short telomeres, multiple organ involvement (Mangaonkar A et al. Blood Cancer J 2021) predicted poor overall survival (OS). We sought to validate these findings in a larger, well annotated adult cohort of TBD patients. Methods: Patients with suspected TBD underwent comprehensive clinical and molecular evaluation through our TBD-dedicated clinic after regulatory approval. TL was assessed through clinical flow cytometry fluorescence in-situ hybridization (FlowFISH).Clinical and laboratory features, including pulmonary imaging, lung volumes/function testing, hepatic imaging (MR elastography/fibroscan) and bone density assessments were retrospectively abstracted. Germline and somatic genetic testing was performed on peripheral blood through targeted panels for known TBD and myeloid genes respectively. Cox proportional hazard model was used to identify significant variables that also retained independent prognostic impact. Results: Overall, 122 patients met criteria for TBD as defined by lymphocyte TL (LTL) <=10th percentile and/or a presence of a germline-TBD variant; 34 patients LTL <1st percentile, 84 1st and the 10th percentile (27 with TBD-germline variants) and 4 with only TBD-germline variants. Median age at diagnosis was 56 (18-77) years, with 72 (59%) males. Clinical features included presence of ILD (n=81, 66%), BMF (n=39, 32%), cirrhosis/hepatic fibrosis (n=19, 38%), bone disease osteopenia/osteoporosis/fractures, n=53, 70%), MDS/AML (n=11, 9%), non-hematological cancer (n=38, 31%), and head and neck cancer (n=2). Germline pathogenic variants were detected in 22 (18%), most frequently in TERT (n=10), RTEL1 (n=7) and TERC (n=2), while variants of uncertain significance (VUS) were seen in 35 (29%) patients, especially in TERT (n=20), TERC/RTEL1(n=6), NAF1 (n=4). Somatic variants in hematopoietic cells were detected in 37 (30%) patients with frequent alterations seen in DNA damage response and repair (PPM1D/TP53, n=11), and splicing component (U2AF1/SF3B1/ZRSR2, n=9) genes. At last follow-up [median of 3 (0-18) years], there were 26 (21%) deaths (most commonly, progressive ILD-18, cancer of lung/breast/pancreas-3, transplant-related complications-2). After censoring patients at the time of any transplantation (lung transplant-26, liver transplant-5, bone marrow transplant-8), the Kaplan-Meier estimate of median OS was not reached. Univariate survival analysis found adverse OS predicted by older age at diagnosis (P=0.006), presence of ILD (P=0.0002), hepatic fibrosis/cirrhosis (P=0.02), and somatic DNA repair variants (P=0.03). Multivariate model analysis found that only presence of ILD retained independent prognostic impact (HR=2, P=0.02). Among radiographic ILD subtypes, UIP was the most common (51%), followed by NSIP (10%), and others (6%), with median FEV1 of 2L (range: 0.5-4.6), FVC 2.4L (0.7-6.2), and TLC 4L (1.9-7.4). TBD-ILD patients were older (P<0.0001) with a male preponderance (P=0.03), 52 (64%) with multi-organ involvement, and had a less severe hematological phenotype [lower incidence of BMF (P<0.0001) and fetal hemoglobin elevation (P=0.01)], more frequent bone disease (P=0.0009), relatively longer telomeres in lymphocytes (P=0.04), and no particular association with any germline or somatic genetic alterations. Conclusions: Presence of ILD is an independent and significant predictor of adverse survival in adult TBD. Within adult TBD, patients with ILD represent a unique clinical subtype without any obvious genetic or pathologic correlates. Focusing on definitive therapeutic measures in this subgroup of adult TBD has the best chance to alter natural history and improve outcomes.

Background: Philadelphia (Ph)-like acute lymphoblastic leukemia (ALL) is a heterogenous subtype of B-ALL defined by the presence of gene expression profiling similar to Ph+ ALL in the absence of a BCR::ABL1 fusion. Ph-like ALL has lower response rates to standard frontline therapies and carries a poorer prognosis when compared to other B-ALL subtypes. However, the role in which specific patient characteristics may impact responses is not well described. Our aim for this retrospective study was to evaluate the characteristics and outcomes of a real-world cohort of patients (pts) with Ph-like ALL across multiple institutions, including describing key patient characteristics, treatments, and factors that may contribute to minimal residual disease (MRD) status and treatment response. Methods: We conducted a retrospective review of adult pts with Ph-like ALL diagnosed and treated at the University of New Mexico, Mayo Clinic Phoenix, University of Chicago, and University of Michigan between 1/1/18 - 2/1/2024. Pts were eligible if they carried a diagnosis of B-ALL, and were determined to have Ph-like ALL according to each institutional diagnostic algorithm. Descriptive statistics, ANOVA, and Fisher's exact test were employed to summarize various clinical characteristics and their associations. Cox regression analysis was utilized to estimate the median survival time and assess the relationship between clinical characteristics and survival outcomes, including overall survival and progression-free survival. All statistical analyses were conducted using the R statistical software. Results: 67 pts were identified with a median age of 34.2 (IQR 28.5) and 35.8% were female. Twenty-eight pts identified as Hispanic or Latino (H/L) (43.1%), 25 (38.5%) identified as non-Hispanic White/Caucasian (NHW), 10 (15.4%) as American Indian/Alaska Native (AI/AN), and 2 (3.1%) as Asian/Pacific Islander. Thirteen pts (19.4%) had central nervous system (CNS) involvement at diagnosis, 22.4% of pts had extramedullary disease, and, in those who had NGS or cytogenomic microarray testing (n=49), 51% had an identified mutation/deletion in IKZF1. Initial treatment varied widely with pts receiving most commonly: Children's Oncology Group (COG) protocols (22.4%), CALGB 10403 (22.4%), HyperCVAD (11.9%), and CALGB 8811 (10.4%). Fifty-eight percent achieved a CR/CRi and 21% were refractory to initial therapy. Thirteen percent of pts received a Jak inhibitor and 6% of pts were treated with a TKI. Thirty pts (50.8%) underwent allogeneic stem cell transplant, with 8 of those pts (26.7%) experiencing a relapse post-transplant. Nine pts (13.4%) underwent treatment with CAR-T therapy with few pts experiencing grade 2 or higher cytokine release syndrome (CRS) or immune effector cell-associated neurotoxicity syndrome (ICANS). Pts with CNS disease at diagnosis were less likely to achieve a CR/CRi compared to those without CNS disease at diagnosis (33.3% vs 64.0%; p=0.12). Pts identifying as AI/AN were more likely to be refractory to their first treatment compared to other racial/ethnic groups (75%, p=0.002). Forty two percent of pts never achieved MRD negativity (< 0.01% by flow cytometry) during treatment; pts identifying as H/L and AI/AN had a higher rate of MRD positivity after induction compared to NHW pts (56% and 70% vs. 25%; p=0.02). In pts with IKZF1 mutation, 57.1% did not achieve MRD negativity compared to 21.7% in pts without a mutation (p=0.029). The median overall survival (OS) was 66.3 months (mos) and the median progression-free survival (PFS) was 15.7 mos. Pts who did not achieve MRD negativity after initial treatment had shorter OS compared to those who did achieve MRD negativity, 33.9 mos vs 66.3 mos (p=0.086). Progression-free survival (PFS) was significantly shorter for patients who did not achieve MRD negativity after initial treatment compared to those who did, 3.9 mos vs 43.9 mos (p=0.001). PFS was shorter in pts who identify as AI/AN compared to H/L and NHW pts (2 mos vs 35.7 mos and 35.7 mos; p=0.046). Conclusion: Pts with Ph-like ALL experience poor response rates to therapies used to treat B-ALL, highlighting the urgent need for novel therapies and treatment strategies. We identified race/ethnicity and CNS disease at diagnosis as risk factors for poor treatment response. In addition, race/ethnicity and the presence of an IKZF1 mutation was associated with worse rates of MRD negativity during treatment.

Background: FL3B is the least common among FL subtypes, accounting for 5-10% of cases. Almost half of FL3B tumors have concurrent diffuse large B cell lymphoma (DLBCL) in the diagnostic tissue biopsy, while FL3B rarely coexists with FL1-2 or FL3A. Several lines of evidence suggest that FL3B displays distinct biological and clinical characteristics resembling aggressive DLBCL rather than the indolent FL1-3A. Accordingly, DLBCL anthracycline-containing regimens, such as R-CHOP, are the mainstay of therapy for FL3B with or without coexisting DLBCL. However, while some studies show that R-CHOP therapy in FL3B was associated with 5-year overall survival (OS) rate of 54%, others report outcomes comparable to FL3A with 79-90% survival. Additional controversy involves the clinical implication of pure FL3B (FL3Bp) vs FL3B with concurrent DLBCL (FL3Bc). Thus, it remains unclear if FL3B clinically resembles DLBCL or lower-grade FL and whether FL3Bp has a different prognosis from FL3Bc. To address these questions, we performed a pooled study of two large prospective multicenter study cohorts to compare the clinical characteristics and outcomes of newly diagnosed FL3B with FL1-2, FL3A and DLBCL patients, all of whom were uniformly treated with frontline R-CHOP. Patients and Methods: Weevaluated 469 newly diagnosed patients with FL1-2 (n=216), FL3A (n=170) and FL3B (n=83) who received R-CHOP within 6 months of diagnosis and 739 de novo DLBCL (GCB n=455 and non-GCB n=284) who were prospectively enrolled into the Molecular Epidemiology Resource (MER) and the Lymphoma Epidemiology of Outcomes (LEO) cohorts between 2002 and 2021. FL3B cases were designated as FL3Bc and FL3Bp based on the presence or absence of coexisting DLBCL, respectively. Histologic diagnosis was determined by an expert pathologist at each participating center and centrally reviewed. Event free survival (EFS) and OS were defined as time from diagnosis to progression, relapse, retreatment or death, and early progression defined as failing to achieve EFS at 24 months (EFS24). Associations between clinical features and EFS or OS were evaluated using Kaplan Meier curves and Cox proportional hazards models unadjusted and adjusted for age and FLIPI (comparisons with FL1-2 and FL3A) or IPI (comparisons with DLBCL). Results: The median age was 61 years (range, 18-94 years). Among FL3B patients, 21 (25%) had FL3Bc and 62 (75%) FL3Bp. Baseline characteristics and outcomes were broadly similar between the two FL3B subtypes. We then compared all FL3B patients to those with lower-grade FL. Patients with FL3B showed similar clinical features to those with FL1-2 and FL3A, with exception for a lower tumor burden. After R-CHOP, FL1-2 patients had an inferior EFS (HR 2.13 95%CI 1.31-3.46) than those with FL3B, whereas there was no difference compared to FL3A. OS was similar across all FL grades. Although FL1-2 patients failed to achieve EFS24 more frequently than FL3B and FL3A (34% vs 18% and 15%, p<0.001), FL3B patients who did fail EFS24 had almost three folds higher risk of subsequent mortality (HR 2.84 95%CI 1.35-6.01) than other FLs. At 5-year follow-up, FL3B patients had twice the risk of relapse with an aggressive subtype (i.e., DLBCL, high-grade B-cell lymphoma) than those with FL1-2 and FL3A, who instead often recurred with indolent disease (i.e., FL1-2, FL3A; p<0.001). We further compared FL3B patients to those with DLBCL classified based on cell-of-origin into GCB and non-GCB subtypes. At diagnosis, patients with FL3B had more favorable clinical features than those with GCB and non-GCB DLBCL. Compared to FL3B, patients with non-GCB DLBCL had an inferior EFS (HR 1.73 95%CI 1.07-2.79) and OS (HR 2.04 95%CI 1.11-3.75), while those with GCB DLBCL did not show a significant difference in EFS (HR 1.41 95%CI 0.88-2.25) or OS (HR 1.69, 95%CI 0.93-3.06) likely due to insufficient statistical power. Patients with FL3B failed EFS24 less frequently than patients with GCB or non-GCB DLBCL (17% vs 25% and 32%; p=0.01). Among patients who failed EFS24, those with FL3B had a similar subsequent OS as both GCB (HR 1.41 95%CI 0.73-2.72) and non-GCB DLBCL (HR 1.27 95%CI 0.65-2.47). Conclusions: We report that FL3Bp and FL3Bc appear clinically similar. While most FL3B patients have a prognosis comparable to FL1-2 and FL3A, 18% exhibit aggressive behavior with poor outcome reminiscent of DLBCL. Future studies with a larger population will be needed to confirm our findings.

Background: Immunochemotherapy is the current standard-of-care frontline therapy for diffuse large B-cell lymphoma (DLBCL). Our group previously reported that addition of the mTOR inhibitor everolimus to R-CHOP resulted in excellent efficacy in the Alliance N1085 trial (Witzig TE et al, Blood Cancer J, 2017, 7(6):e576), with 23 of 24 patients achieving event-free survival at 24 months (EFS24), supporting further investigation of PI3K/mTOR targeting in DLBCL. New insights into molecular classification of DLBCL suggest that multiple genetic subtypes of DLBCL (eg, MCD, BN2, ST2, and EZB per LymphGen classification) may be susceptible to PI3K/mTOR targeting. Therefore, we conducted a phase 1/1b trial to investigate the safety and efficacy of combination therapy with a novel PI3K inhibitor parsaclisib and standard immunochemotherapy. Methods: Adult patients with newly diagnosed DLBCL were eligible if any of the following was present: 1) non-GCB subtype per the Hans algorithm; 2) protein expression of either MYC (≥40%) or BCL2 (≥50%) by immunohistochemistry; or 3) MYC rearrangement by FISH. Patients with high grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements were also eligible. Phase 1 followed a 3+3 design to determine the maximum tolerated dose (MTD) of parsaclisib (plus R-CHOP) to be used in Phase 1b (dose expansion). The primary efficacy endpoint in phase 1/1b was complete response (CR) rate by PET. A polatuzumab vedotin (Pola) safety lead-in cohort was added later to explore the safety and efficacy of parsaclisib (at MTD) plus Pola-R-CHP. Results: From July 2020 to May 2023, 50 patients were enrolled; 1 patient withdrew consent before study treatment and was excluded from this analysis. Nine patients were treated in Phase 1, 33 in Phase 1b, and 7 in the Pola cohort. The median age at diagnosis was 66 years (range 20-86), and 20 (41%) were female. Two (4%) patients had ECOG PS ≥2, 26 (53%) had elevated LDH, 19 (39%) had >1 extranodal site, 37 (76%) had stage III/IV, and 25 (51%) had high-intermediate or high-risk International Prognostic Index (3-5). 23 (47%) had non-GCB subtype, 23 (46.9%) had MYC or BCL2 single expression, 21 (42.9%) had MYC/BCL2 double expression, and 6 (12%) had MYC rearrangement (2 with BCL2 and/or BCL6 rearrangements). In Phase 1, 3 patients were treated at dose level 1 (parsaclisib 20 mg QD, d1-10) and 6 at dose level 2 (parsaclisib 20 mg QD, d1-14). No dose limiting toxicity was observed. Therefore, dose level 2 for parsaclisib was the MTD and was used in Phase 1b. In the Pola cohort (n=7), only 1 of 6 evaluable patients experienced significant toxicity (grade 3 diarrhea). Among all 49 patients, the most common treatment-related adverse event (TRAE) of any grade included neutropenia (83.7%), thrombocytopenia (79.6%), leukopenia (77.6%), lymphopenia (71.4%), anemia (71.4%), nausea (63.3%), fatigue (40.8%), peripheral sensory neuropathy (36.7%), constipation (24.5%), and diarrhea (22.4%), and the most common grade ≥3 TRAE included neutropenia (71.4%), leukopenia (69.4%), lymphopenia (49.0%), thrombocytopenia (20.4%), anemia (16.3%), febrile neutropenia (6.1%), and diarrhea (6.1%). In Phase 1/1b (n=42), the overall response rate (ORR) to parsaclisib plus R-CHOP was 97.6%, and the CR rate was 90.5%. After a median follow-up of 28.5 months (95% CI 27.7-32.7), the estimated 2-year progression-free survival (PFS) rate was 84.6% (95% CI 73.9-96.8), and the estimated 2-year overall survival (OS) rate was 95.1% (95% CI 88.7-100.0). In the Pola cohort, the ORR to parsaclisib plus Pola-R-CHP was 100% and the CR rate was 100%. After a median follow-up of 15.6 months (95% CI 13.5-NE), 1 patient had disease relapse at 11.95 months, and all patients were alive. Conclusions: Addition of the PI3K inhibitor parsaclisib to R-CHOP or Pola-R-CHP immunochemotherapy is considered safe in patients with newly diagnosed DLBCL. Combination of parsaclisib and standard immunochemotherapy resulted in high ORR and CR rate and encouraging preliminary PFS and OS outcomes patients with high-risk DLBCL. These data support further investigation of PI3K/mTOR targeting in newly diagnosed DLBCL in future trials.

Introduction. Ciltacabtagene autoleucel (cilta-cel) and idecabtagene vicleucel (ide-cel), two anti-B-cell maturation antigen (BCMA) CAR T therapies, have demonstrated remarkable responses and improved survival among patients with relapsed/refractory multiple myeloma (RRMM) in the clinical trials and standard of care (SOC) setting. Here, we compare safety, efficacy, and survival for patients treated with SOC ide-cel and cilta-cel. Methods. Data were from a retrospective chart review of RRMM patients leukapheresed by 12/31/2022 with the intent to receive SOC ide- or cilta-cel at 19 institutions in the US Multiple Myeloma Immunotherapy Consortium. An inverse probability of treatment weighting (IPTW) approach was used to compare outcomes by therapy type (cilta- vs. ide-cel), balancing on age, sex, race and ethnicity, performance status, extramedullary disease, high-risk cytogenetics, prior BCMA therapy, bone marrow plasma cells, penta-refractory status, lymphodepleting chemotherapy, baseline ferritin, low cell dose, and bridging therapy response. Logistic regression and Cox proportional hazard models were used to examine the association of treatment type with safety, efficacy, and survival accordingly, while adjusting for IPTW weights. We employed propensity score matching utilizing the same covariates to identify the association of treatment type with progression-free survival (PFS) within relevant patient sub-groups. Results. A total of 641 patients were leukapheresed by 12/31/2022 with ide-cel (n=386) and cilta-cel (n=255). 586 patients were infused (n=350 for ide-cel; n=236 for cilta-cel) with a median follow-up of 13.0 and 12.6 months, respectively. After IPTW, patient characteristics were well-balanced. Patients treated with cilta-cel were more likely to have grade ≥ 3 cytokine release syndrome (CRS) (OR=5.52, 95% CI=1.76-17.30, p=0.004), infections (OR=2.07, 95% CI=1.44-2.97, p<0.001), and delayed neurotoxicity (NT) (OR=20.97, 95% CI=4.75-92.42, p<0.001) compared to patients treated with ide-cel. In the cilta-cel cohort, 24 patients (10%) experienced delayed NT compared to 2 patients (1%) in the ide-cel cohort. Although not statistically significant, patients treated with cilta-cel were more likely to have any second primary malignancies (SPMs) (OR=1.87, 95% CI=0.94-3.71, p=0.08) and any SPMs excluding non-melanoma skin cancers (OR=1.78, 95% CI=0.78-4.10, p=0.2) but no association was observed for odds of hematologic SPMs (OR=0.98, 95% CI=0.26-3.61). No association was observed for therapy type with any or severe immune effector cell-associated neurotoxicity syndrome, any CRS, severe cytopenias, and non-relapse mortality. Compared to ide-cel, cilta-cel was associated with better treatment responses of ≥ complete response (OR=2.38, 95% CI=1.61-3.51, p<0.001) and ≥ partial response (OR=1.74, 95% CI=0.99-3.05, p=0.06). Patients treated with cilta-cel had a longer PFS and overall survival (OS) than ide-cel (HR=0.47, 95% CI=0.35-0.62, p<0.001 and HR=0.63, 95% CI=0.42-0.93, p=0.02, respectively), and these findings were similar in the intention to treat cohort (PFS: HR=0.44, 95% CI=0.34-0.55, p<0.001; OS: HR=0.55, 95% CI=0.41-0.73, p<0.001, respectively). We observed consistent findings when repeating the analyses restricting the ide-cel cohort to patients infused during the same time-period as FDA approval for cilta-cel (≥ March 2022), restricting to patients with data on all covariates, and restricting to sites that contributed data for both products. In a propensity matched population, (n=380; n=190 for cilta-cel and n=190 for ide-cel), patients treated with cilta-cel had superior PFS compared to those treated with ide-cel in most subgroups with respect to age and disease characteristics including extramedullary disease, high-risk cytogenetics, and elevated baseline ferritin (p<0.05). Conclusion. Our results suggest superior efficacy of cilta-cel with a higher incidence of certain toxicities compared to ide-cel in the SOC setting. This study provides valuable information for patient counseling and guiding the selection of CAR T-cell therapy for specific patient populations. Further validation through similar large-scale real-world experiences or prospective studies is needed to confirm our results and enhance applicability in the clinical setting. *DH, LP, & DD are co-first authors * YL, KP, & SS are co-last authors

Introduction: The optimal induction for younger fit patients (pts) with mantle cell lymphoma (MCL) is unknown; though intensive chemoimmunotherapy (CIT) containing high dose cytarabine has been shown to prolong remission. Achieving molecular remission is an independent predictor of outcomes post induction therapy in patients with MCL. Incorporating undetectable measurable residual disease (uMRD) status into the primary endpoint may be preferable to progression-free survival (PFS), particularly when approaches following induction are varied (e.g., ASCT, maintenance treatment, observation). Induction with 3 cycles of bendamustine and rituximab followed by 3 cycles of cytarabine and rituximab (BR/CR) is associated with high complete metabolic response (CMR) and uMRD rates (Armand et al., BJH 2016; Merryman et al., Blood Adv 2020). Bruton's tyrosine kinase inhibitors (BTKi) including ibrutinib and acalabrutinib (A) in combination with CIT are highly effective in MCL (Wang et al., EHA 2024, LBA 3439). In 2019, the US Intergroup activated EA4181 to explore the efficacy with the addition of fixed duration BTKi, to BR or BR/CR for patients with MCL ≤ 70 years old. Patients and methods: Patients were randomized 1:1:1 (stratified by MIPI risk status) to 6 cycles of BR/CR (control arm), BR/CR-A, or BR-A. Cytarabine was dosed at 2 g/m2 Q12 hours x 4, with dose reductions based on age and creatinine clearance. Acalabrutinib was dosed at 100 mg BID continuously on BR cycles with the BR/CR-A and BR-A arms and at 100 mg BID on days 1-7 and 22-28 with CR cycles on the BR/CR-A arm to mitigate hematologic toxicity. Consolidation approaches following induction were at the discretion of the treating physician. The primary endpoint was a composite of PET/CT CMR and peripheral blood uMRD rate (< 1 in 105). ClonoSEQ (Adaptive Biotechnologies) was performed at baseline and MRD testing was obtained at the end of induction. Secondary clinical objectives included PFS and overall survival (OS) at 36 months (mo), objective response rates (ORR), and toxicity rates. With 108 patients per arm expected, there was 86% power to detect an increase in PET/CT CMR/uMRD rate from 60% in the control arm to 75% in either BR/CR-A or BR-A arms using a Z-test with a 10% alpha (1-sided). Results: Between October 2019 and March 2023, 359 participants were randomized to BR/CR (n = 128), BR/CR-A (n = 129), and BR-A (n = 102). BR-A was closed to further accrual by the DSMC based on interim futility analysis for superiority in Fall 2022. The median (range) age was 61 (25, 70), 30% were ≥ 65 years, 77% were male, 89% were white, 89% were non-Hispanic, 18%/43%/39% were low/intermediate/high risk MIPI. Baseline clonal sequence was identified in 308/326 (95%) among samples received. 281/308 were eligible and treated and 260/281 had an end of treatment MRD test result (BR/CR = 85, BR/CR-A = 98, BR-A = 77). This subset (n = 260) is the focus of the primary analysis; sensitivity analysis included 281 eligible and treated pts with trackable clonal marker. In the primary analysis subset, 94%, 91%, and 90% in BR/CR, BR/CR-A, and BR-A arms, respectively, completed 6 cycles of protocol therapy. The PET/CT CMR/uMRD rates were 82% (BR/CR), 82% (BR/CR-A; p = 0.55 vs BR/CR), and 78% (BR-A; p = 0.76 vs BR/CR). In the sensitivity analysis set, PET/CT CMR/uMRD rates were 74% with BR/CR (n = 94), 76% (p = 0.44) with BR/CR-A (n = 106), and 74% (p = 0.52) with BR-A (n = 81). ORR (CMR) rates were 94% (91%), 99% (90%), and 94% (91%) with BR/CR, BR/CR-A, and BR-A, respectively. At a median follow-up of 27.9 mo, estimated 12-mo PFS/OS were 86%/94% (BR/CR), 89%/98% (BR/CR-A) and 87%/95% (BR-A). The proportion of treatment-related grade 3 or higher adverse events (AE) was 78%/88%/73%, with neutropenia in 52%/58%/27%, anemia in 23%/32%/3%, thrombocytopenia in 55%/66%/6%, and febrile neutropenia in 11%/12%/4%; treatment discontinuation due to AE occurred in 5%/7%/8% in BR/CR, BR/CR-A, and BR-A arms, respectively. Conclusion: High PET/CT CMR uMRD rates were seen in all 3 arms. BR/CR can be considered as a standard induction in pts ≤ 70. Addition of acalabrutinib to the standard arm added toxicity without improvement in efficacy, suggesting acalabrutinib should be avoided during Ara-C cycles. BR-A was found not superior and closed early by the DSMC; however, it is the least toxic arm with similar efficacy, and represents an appealing option to avoid high dose cytarabine.

Background: Polatuzumab vedotin (Pola) is an antibody drug conjugate targeting CD79b that incorporates the microtubule disrupting monomethyl auristatin E payload. Pola was approved in 2023 for the upfront treatment of diffuse large B cell lymphoma (DLBCL) in combination with rituximab, cyclophosphamide, doxorubicin, and prednisone (polaRCHP) based on the POLARIX trial. However, the activity of pola appears to vary based on DLBCL cell of origin (COO) subtype, with greater efficacy in activated B cell (ABC) DLBCL compared to germinal center B cell (GCB) DLBCL (Russler-Germain Blood 2023). When outcomes in POLARIX are stratified by COO, polaRCHP demonstrated progression free survival (PFS) and overall survival (OS) benefits over RCHOP in patients with ABC but not GCB subtype DLBCL (PFS HR 0.34 ABC vs 1.03 GCB, OS HR 0.27 ABC vs 1.64 GCB; Morschhauser ASH 2023 and FDA data). Most prospective studies of pola used gene expression to assess COO, which is not readily clinically available. This study aims to examine if COO subtype by Hans algorithm (based on CD10, BCL6, and MUM1 expression by immunohistochemistry) is predictive of pola responses and outcomes in patients with large B cell lymphoma (LBCL). Methods: We conducted a retrospective, multicenter observational study of adults with LBCL who received pola (monotherapy or in combination) from 2015-2024 with Hans algorithm COO data and response assessment available. Patients were stratified by receipt of pola in the frontline vs relapsed/refractory (R/R) setting. The primary endpoint was overall response rate (ORR) to pola-based treatment in GCB vs non-GCB subtypes. Secondary endpoints included complete response rate (CRR), PFS, and OS. For time to event endpoints, patients responding to pola who received CAR T or stem cell transplantation prior to progression were censored at time of cellular therapy. Demographics were summarized by descriptive statistics. Comparative and survival analyses used Chi squared/Fischer exact tests and Kaplan Meier analysis. Data cutoff was July 1, 2024. Results: 718 patients were included. Median follow-up was 15 months (interquartile range [IQR] 8-32). Median age at LBCL diagnosis was 66 years (IQR 56-74); 62% were men; 69 (10%) had double hit lymphoma (DHL); 129 (18%) had underlying low grade lymphoma. Pola was used in the frontline setting in 293 (41%) patients, of whom 139 (47%) had GCB vs 154 (53%) non-GCB COO. Of the 426 patients receiving pola for R/R LBCL (including one patient receiving pola retreatment), 224 (53%) had GCB vs 202 (47%) non-GCB COO. Among patients receiving pola-based regimens in the R/R setting (GCB vs non-GCB: pola monotherapy = 7% vs 4%, pola + R = 26% vs 26%, pola + BR = 55% vs 61%, pola + other = 12% vs 9%; p = 0.44), the ORR in GCB vs non-GCB LBCL was 36% vs 61% (p < 0.001), while CRR in GCB vs non-GCB was 17% vs 36% (p < 0.001). COO remained a significant component of logistic multivariate regression models of ORR (p < 0.001) and CRR (p < 0.001) when incorporating IPI at original LBCL diagnosis, histology, DHL status, and refractory status to frontline therapy. Despite this, no significant PFS or OS differences by COO were seen, potentially due to approximately 1/4 patients being censored due to receiving subsequent cellular therapy (e.g. CAR T) prior to progression. In patients receiving frontline pola-based regimens (of which 275 [94%] included an anthracycline), ORR and CRR were similar in GCB vs non-GCB (ORR 89% vs 88% p > 0.5; CRR 76% vs 77% p > 0.5). While PFS and OS were similar between COO groups in the frontline cohort, follow-up and cohort size were limited. Conclusion: Based on this real-world evidence, COO classification by Hans algorithm is a strong predictor of the activity of pola-containing therapy in R/R LBCL, with significantly higher ORR and CRR in patients with non-GCB compared to GCB COO LBCL. This aligns with the cumulative existing evidence. ORR and CRR to pola-containing therapy in the frontline setting did not differ significantly by COO subtype, but longer follow-up of larger cohorts is needed to clarify the predictive role of COO by Hans algorithm in this setting, especially considering the PFS advantage with polaRCHP in POLARIX was not associated with significant differences in ORR or CRR. Overall, clinicians should consider factoring COO subtype into treatment decisions regarding pola-containing regimens, and studies of pola-based therapies should stratify patients and report outcomes by COO subtype.

Background: ctDNA clearance after frontline DLBCL tx has shown strong prognostic value for favorable outcomes, with the potential to improve MRD-driven therapeutic strategies and establish MRD as a surrogate endpoint in future studies (Roschewski M, et al. Blood 2022; Goldstein J, et al. Blood 2023). However, further study is needed to evaluate the association of this noninvasive approach with efficacy outcomes after 2L LBCL tx. We previously reported ctDNA analysis after liso-cel infusion in TRANSFORM (NCT03575351; Stepan L, et al. Blood 2023;142[suppl 1]). Here, we describe the predictive value of pre-tx and on-tx ctDNA levels for durable clinical benefit (CR and event-free survival [EFS]) in both liso-cel and SOC arms from TRANSFORM (Kamdar M, et al. J Clin Oncol 2024), evaluating ctDNA as an earlier surrogate for conventional clinical outcomes. Methods: Baseline (prerandomization) and longitudinal ctDNA levels were assessed in randomized pts treated with liso-cel or SOC in TRANSFORM using the phased variant enrichment and detection sequencing assay (PhasED-Seq; Foresight Diagnostics). Phased variants were identified from baseline plasma samples for longitudinal ctDNA monitoring at multiple on-tx time points, as previously described (Stepan L, et al. Blood 2023;142[suppl 1]). Randomization was defined as study Day 1. Association of ctDNA levels with response per independent review committee using Lugano 2014 criteria and EFS was investigated at various predefined time points, including Day 43 (after 2 cycles of salvage immunochemotherapy for SOC; Day 15 after liso-cel infusion), Day 64 (after 3 cycles of salvage immunochemotherapy for SOC; 1 month after liso-cel infusion), and Day 126 (within 2 months after ASCT; 3 months after liso-cel infusion). To assess the surrogacy value of ctDNA, ctDNA-MRD dynamics and ctDNA clearance were investigated within both arms. Results: In pooled analyses combining the liso-cel and SOC arms, higher baseline ctDNA levels (above the median) were associated with shorter EFS (P = 0.05). Pts achieving Day 126 CR had substantial reductions in ctDNA burden vs baseline, while pts with PD or stable disease had persistently high ctDNA levels vs baseline. Achieving undetectable ctDNA at different time points was associated with significantly longer EFS in pooled analyses, observed as early as study visit Day 43, with the strongest association at Day 126. HR (95% CI) for inferior EFS was 3.0 (1.6-5.7) at Day 43, 3.8 (2.1-7.0) at Day 64, and 4.2 (2.3-7.7) at Day 126 in pts with detectable vs undetectable ctDNA. In the analysis by tx arm, consistent with the pooled analyses, ctDNA clearance was associated with EFS benefit at all measured time points with either liso-cel or SOC. Significantly more pts achieved undetectable ctDNA with liso-cel vs SOC during the study (39/63 [62%] vs 25/65 [38%], respectively; P = 0.013), consistent with superior EFS (primary endpoint) with liso-cel in TRANSFORM. All pts in the SOC arm with evaluable ctDNA at Day 126 (n = 28) had received high-dose chemotherapy (HDCT)/ASCT. However, pts with undetectable ctDNA in the liso-cel vs SOC arm had longer EFS at all predefined time points and had statistically longer EFS at Day 126 (SOC vs liso-cel: HR, 3.9 [95% CI, 1.4-10.6]), indicating a deeper and more durable response with liso-cel vs SOC. In pts with CR, ctDNA showed significant predictive value beyond the response assessment at all time points in the liso-cel arm with a HR (95% CI) of 3.8 (1.3-11.0) at Day 64 and 7.0 (2.0-24.3) at Day 126 for EFS in pts with detectable ctDNA vs undetectable ctDNA. Among pts in the SOC arm who experienced subsequent PD despite achieving CR (all received HDCT/ASCT) and undetectable ctDNA at Day 126, serial ctDNA assessment showed consistent reversion to detectable ctDNA at later time points. Conclusions: ctDNA data from TRANSFORM confirm the value of ctDNA as a biomarker for disease burden monitoring and early prediction of durable clinical benefit after 2L LBCL treatment. Furthermore, longitudinal ctDNA molecular response results agree with previously reported clinical efficacy data and confirm the superiority of liso-cel with deeper responses over the historical SOC in 2L LBCL. ctDNA may have a key role as a surrogate endpoint in future LBCL studies, including after CAR T cell therapies.

Background: Zamto-cel is an investigational autologous tandem CD20-CD19-directed non-cryopreserved CAR-T cell product administered as a fresh formulation to patients (pts) with relapsed/refractory Diffuse Large B Cell Lymphoma (r/r DLBCL) in the DALY II USA clinical trial (NCT04792489), a multicenter, open label, single-arm Phase 2 study. Here, we report efficacy and safety outcomes as part of a pre-planned interim analysis of 59 evaluable patients and 69 patients in the safety population. Methods: Eligible adults had r/r DLBCL after at least 2 prior lines of treatment including anti-CD20 monoclonal antibody and anthracycline-containing regimen and measurable disease per Lugano 2014 classification. Zamto-cel was manufactured utilizing CliniMACS Prodigy® (Miltenyi Biotec), a closed, automated system with a 14-day vein-to-vein time and administered as a fresh formulation. Lymphodepletion chemotherapy was initiated during the manufacturing process (either cyclophosphamide/ fludarabine or bendamustine) prior to receiving a single dose of zamto-cel at a dose of 2.5x106 CAR T cells/kg on Day 0. The primary endpoint was overall response rate (ORR) defined as best overall response (BOR) of either complete response (CR) or partial response (PR). Secondary endpoints included complete response rate (CRR), duration of response (DOR), progression-free survival (PFS), overall survival (OS), safety, and CD19 and CD20 antigen expression at relapse. Results: As of March 29th, 2024, 69 pts received zamto-cel of which 59 were evaluable having received a fresh, conforming product and completed a minimum of 3 months follow-up. Median age was 63 years (range 25-85), 39 (66%) were male. Sixteen pts (27%) received 3 or more lines of prior treatment. The majority of pts (53%) had elevated LDH at study entry, and 49% had ≥ 2 extranodal lesions, indicative of a study population with advanced disease. No pts received any bridging therapy, in the week after apheresis and before lymphodepletion. Only 7 pts (12%) received bendamustine as lymphodepleting regimen. Successful manufacturing of a fresh, in specification product occurred in 91.3% out of 69 treated pts. Four patients received a cryopreserved formulation to permit time for comorbid condition management. The mean viability of the final product was 96.0% with 29.4 % transduction efficacy. No patient died or withdrew during the manufacturing process. The ORR in the evaluable patient population (n=59) as assessed by an Independent Radiology Committee (IRC) was 72.9% (95% CI, 59.7-83.6), with a CRR of 49.2% (95% CI,35.9-62.5). The 6 month and 12 month-PFS was 55% (95%CI, 41-67) and 42% (95%CI, 28-56), respectively; 12 month-OS was 72% (95%CI, 57-83). The median DOR was 11.4 months. All 69 treated pts were assessed for safety outcomes. Treatment-emergent adverse events (TEAEs) were mostly of grade 1-2, the majority of grade ≥ 3 were hematological. Thirty-two pts (46.4%) experienced cytokine release syndrome (CRS), all grade 1-2. Immune effector cell-associated neurotoxicity syndrome (ICANS) was reported in 12 pts (17.4%), grade 1-2 (9 pts; 13.1%); grade 3 (3 pts; 4.3%). One patient experienced immune effector cell-associated hemophagocytic lymphohistiocytosis-like syndrome (IEC-HS), which resolved after 2 days. Biopsies at progression were available in 24 pts. CD19-negative relapse (defined as H Score <100) was seen in 2 pts, CD20-negative relapse was observed in 3 pts. Only one patient experienced loss of both antigens compared to pre-treatment status, demonstrating that most lymphomas maintain target antigen expression at relapse after treatment with zamto-cel. Conclusion: This pre-planned interim analysis represents the first pivotal trial of a tandem CD20-CD19 directed non-cryopreserved CAR-T cell product for patients with third-line r/r DLBCL. The trial plans to enroll 100 evaluable patients and the final data will be presented upon study completion. Among the 59 evaluable patients at the interim analysis, there is encouraging activity and a favorable safety profile in DLBCL patients treated with zamto-cel. Unlike currently registered CAR-T cell products, zamto-cel is administered as a fresh product with a short vein-to-vein time of 14 days with lymphodepletion initiated during the manufacturing process. With a manufacturing success rate of 91% we have demonstrated the feasibility of this process among high-risk patients with r/r DLBCL.

Introduction: T-PLL is a rare, aggressive malignancy with poor prognosis and limited therapies. Outside of prospective trials utilizing alemtuzumab, data is derived primarily from small retrospective series, and limited data on survival outcomes and therapeutic efficacy, particularly beyond frontline therapy are available. In this large multi-center series, with comprehensive clinical data, we evaluated survival and therapeutic outcomes in T-PLL patients, with a focus on identification of prognostic subgroups of T-PLL, that will inform future investigations into the biology and treatment of this disease. Methods: We retrospectively evaluated all patients diagnosed with T-PLL at 15 academic cancer centers throughout the USA between 2000-2023 using the recent TPLL-ISG staging and response criteria with overall response rate (ORR) defined as CR and PR. Overall survival (OS) and progression-free survival (PFS) were assessed using Kaplan-Meier methods and cox proportional hazard models. Single-cell RNA sequencing (scRNAseq) was performed using the standard 10X Genomics platform. Results: 377 patients, with a median follow-up time of 29 months (range: 0-196) were evaluated. The median age at diagnosis was 64 and 51% were male. In evaluated patients (n=223), TCL1A was positive by cytogenetics or FISH in 82%. 61% of patients had CD4+CD8- T-PLL, 11% of patients had CD4-CD8+ T-PLL, and 24% of patients had CD4+CD8+ T-PLL, with 4% unknown. 175 patients (46.4%) had known nodal involvement at diagnosis identified by PET or CT scan. Among treated patients (n=342, 91%), using TPLL-ISG criteria, the ORR to any frontline treatment was 67% (49% CR, 18% PR). Median OS and PFS was 19 months and 10 months in responding patients from the start of treatment initiation. For those treated with frontline alemtuzumab (n=250), the ORR was 74% (58% CR), with a median OS and PFS of 18 and 12 months. 20 patients (5%) were treated with a combination of alemtuzumab/pentostatin frontline with an ORR of 85% (70% CR), which was superior to alemtuzumab alone (ORR 74%, 58% CR). Patients that had frontline chemotherapy (excluding pentostatin, n=48) had a worse ORR of 35% (15% CR) (p<0.001), and a worse PFS of 4 months (p=0.002), when compared to those who received alemtuzumab. Among patients in 1st CR/PR (n=226), 44% (n=99) received an allograft and had an improved 3-year OS of 50% vs 17%, (HR=0.67, 95%CI 0.48-0.93), and 50% improvement in PFS (HR 0.48, 0.33-0.68) compared to those who did not receive an allograft. For patients that received second line treatment (n=176, 52%), re-treatment with alemtuzumab (n=33) produced a 46% ORR (21% CR). Other active second-line treatments included: pentostatin (n=23; 44% ORR, 17% CR), ruxolitinib-based regimens (n=4; 25% ORR, 0% CR), venetoclax-based regimens (n=13; 39% ORR, 8% CR), bendamustine (n=10; 30% ORR, 0% CR), and nelarabine (n=4; 75% ORR, 50% CR). In subgroup survival analysis, TCL1A+ patients had a worse OS and PFS when compared to TCL1A- patients (23 months vs 43 months; p=0.02), and (14 months vs 24 months; p=0.02) respectively, with HR 1.58 (1.08, 2.31) (p=0.02) for OS and HR 1.62 (1.09-2.40) (p=0.02) for PFS. Furthermore, CD4- T-PLL had worse OS (16 months vs 25 months) when compared to CD4+ patients [HR 1.57 (1.08, 2.27), p=0.02]. Single cell RNA seq in 13 patients, including 3 TCL1A- patients, with a total of 66,269 T-PLL cells, demonstrated a unique RNA signature between the CD4+/- and TCL1A+/- patients, suggesting these represent unique molecular subtypes of T-PLL. Conclusions: In this large, multi-center study of T-PLL, frontline treatment with a combination of alemtuzumab/pentostatin improved response rates and OS. Further, among patients who attained a CR, allograft improved OS & PFS vs no allograft. In relapsed T-PLL, retreatment with alemtuzumab had a high ORR, and we report significant activity of multiple novel/alternative agents with the largest reported numbers to date. Intriguingly, TCL1A+, and CD4- T- PLL had worse OS/PFS, and scRNAseq confirmed unique molecular signatures in these populations, suggesting these represent novel molecular subtypes of T-PLL with prognostic significance. These studies form the foundation for future, targeted, therapeutic studies in this rare, aggressive disease with few treatment options.