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Abstract Background. Uproleselan (GMI-1271) is an antagonist of E-selectin, an adhesion molecule expressed on endothelial cells in the vascular niche of the bone marrow. Engagement of E-selectin by acute myeloid leukemia (AML) blasts, which express E-selectin ligand, activates cell survival pathways and promotes resistance to chemotherapy. In multiple preclinical AML tumor models, blockade of E-selectin with uproleselan enhanced the efficacy of chemotherapy. Methods. We conducted a phase (P) 2/3 study in which subjects age ≥ 60 years with untreated, FLT3 unmutated AML were randomized to receive conventional chemotherapy with or without uproleselan. Induction chemotherapy consisted of 7+3 (cytarabine + daunorubicin) +/- uproleselan with a second induction cycle with 5+2 +/- uproleselan administered for residual AML. Uproleselan 800 mg IV was administered as a single dose 24 hours before the first dose of chemotherapy and then every 12 hours until 48 hours after the completion of chemotherapy. Post-remission therapy consisted of up to 3 cycles intermediate-dose cytarabine 2 gm/m2 IV d1-5 +/- uproleselan. Allogeneic transplant was performed at the discretion of the treating physician. The primary endpoint was event-free survival (EFS) for P2 and overall survival (OS) for P3. Results. The study enrolled 267 patients between March 2019 and November 2021, with a median age of 66.9 years (IQR 63.8-69.9). 32% were classified as 2017 ELN intermediate risk, 41% as adverse risk, with 62 (29%) having complex karyotype / mutated TP53. The P2 analysis was to be performed when at least 191 events were observed. However, as the required events had not been observed > 5 years after study initiation and 3 years after completion of P2 enrollment, an independent statistician was consulted, and the analysis plan was amended to conduct the P2 EFS analysis in November 2024. With a median follow-up of 53.1 months, the EFS was not significantly different between the two arms (HR 0.90, 95% CI 0.70-1.23, P=0.58). As the study did not meet its P2 EFS endpoint, enrollment in the P3 was not initiated. There was no significant difference in OS between the 2 arms (HR 0.99, p=0.94) with a median OS in the uproleselan arm of 23.6 months (95% CI 15.1-35.4 mo) vs 19.8 months (14.6-36.3) for the control arm. The overall rate of CR/CRi after induction was 65% (CR: 60%) in the uproleselan arm versus 63% (CR: 55%) in the control. MRD results by either local or central assessment in patients achieving a CR/CRi were available for 129 patients with the MRDneg rate of 81 % (95% CI 69.5-89.9%) in the uproleselan arm vs 67% (54.3-78.4%) in the control arm (p=0.053), The 30-day mortality was 5.3% for uproleselan vs 8.1% in the control. Forty-eight (36%) patients in the uproleselan arm and 55 (40%) in the control arm underwent alloHCT, including 37 (27%) and 29 (22%) in CR1, respectively (p = 0.34). In patients undergoing alloHCT in CR1, those randomized to uproleselan and allografted in CR1 had an HR 0.71 (95% CI 0.34-1.47; P=0.35) compared to the control arm. Expression of E-selectin ligand on AML blasts was performed by flow cytometry, with subjects having an E-selectin ligand expression above the median having a trend towards worse median OS 16.2 (95% CI 11.4-24.3) vs 32.2 (15.9-57.8) months, but was not affected by treatment arm. In both univariate and multivariate analyses, WBC at baseline, ELN genetic risk group, and TP53/complex karyotype were found to be associated with EFS. A subgroup analysis identified an improvement in EFS favoring uproleselan in patients with mutated ASXL1 (HR 0.25, 95% CI 0.08-0.78, p<0.017). Conclusions. Although the addition of uproleselan to intensive chemotherapy was associated with a higher rate of MRDneg CR/CRi in older adults with AML, uproleselan failed to improve EFS or OS and did not overcome the adverse outcomes associated with higher E-selectin expression on AML blasts. The median OS of 20-24 months with an overall 3-year OS of almost 40% for patients treated on this study exceeds previous CALGB / US Cooperative Group studies (median OS ~12 months, 3-year OS ~20%) and continues to support a role for intensive chemotherapy in the management of older adults with AML. Furthermore, this study suggests a potential benefit for uproleselan in patients harboring ASXL1 mutations, which may warrant further investigation. ClinicalTrials.gov Identifier: NCT03701308

Abstract Despite a characteristic indolent course, a substantial subset of follicular lymphoma (FL) patients has an early relapse with a poor outcome. Thus far, efforts to identify factors that predict survival have been unsuccessful. However, we and others have demonstrated the prognostic relevance of CD4+ T cells in the tumor microenvironment (TME) of FL and developed a bio-clinical risk model (called BioFLIPI) that offers improved risk stratification (Mondello et al, BCJ 2021). However, the mechanisms defining different BioFLIPI scores remain to be fully understood. To identify the programs associated with the BioFLIPI scores, we first interrogated the RNA-seq of purified B cells from 67 newly diagnosed FL1-3A (BioFLIPI 1 n=21; BioFLIPI 2-3 n=36; BioFLIPI 4 n=10). We found 1,156 upregulated genes and downregulation of 930 genes in BioFLIPI 4 vs 1, including well-known immune molecules such as CD70, IL10RA, CD69, and CCR6 (FDR<0.05). Gene set enrichment analysis (GSEA) using the MSigDB confirmed a negative enrichment in multiple immune response and interferon gamma signatures and revealed striking positive enrichment for cell proliferation and antigen presentation pathways in BioFLIPI 4 compared to BioFLIPI 1 tumors. The same pathways were dysregulated in BioFLIPI 2-3 but a lower magnitude. To investigate the somatic mutations associated with different BioFLIPI scores, we performed WES of the same 67 FLs and further expanded this cohort for a total of 90 patients (BioFLIPI 1 n=26; BioFLIPI 2-3 n=51; BioFLIPI 4 n=13). We found enrichment for mutations in several regulators of the germinal center in BioFLIPI 4 and 2-3, such as MEF2B (p=0.029), FOXO1 (p=0.038) and IRF8 (p=0.035), suggesting the cooperation of multiple oncogenic events promoting lymphomagenesis. In contrast, BioFLIPI 1 tumors harbored a higher rate of mutations in TNFRSF14 gene, known to enhance anti-lymphoma immune response. To investigate whether BioFLIPI modulates immune signatures of the microenvironment, we performed TME deconvolution by applying CIBERSORTx to bulk RNA-seq of these 67 FLs. We found that FLs with BioFLIPI 4 and 2-3 were enriched for CD4+ Tcm exh (p=0.02), Tem exh (p=0.04), Tfhexh (p=0.07) and NK cells (p=0.01) compared to BioFLIPI 1. In line with this data, CyTOF performed on a subset of these patients (BioFLIPI 1 n=12; BioFLIPI 2-3 n=25; BioFLIPI 4 n=6) confirmed progressive increase of CD4+ Tcm exh (p=0.006), Tem exh (p=0.009) and Tfh exh (p=0.025) cells from BioFLIPI 1 to BioFLIPI 4. Single cell RNA/BCR-seq of 21 FLs (BioFLIPI 1 n=6; BioFLIPI 2-3 n=12; BioFLIPI 4 n=3) corroborated a higher abundance of Tem exh, cytotoxic (CTL) Tem exh, Tfhexh and NK cells in BioFLIPI 4 and 2-3. Conversely, CD8+ naïve T cells were prevalent in BioFLIPI 1 tumors. Differential gene expression in T cell clusters from BioFLIPI 4 vs BioFLIPI 1 FL revealed a marked upregulation of multiple immune genes involved in antigen presentation (e.g., HLA-DRB, HLA-DQA, HLA-DPA/B) and immune response (e.g., ETS1, TNFSF8, IL7R). GSEA showed a positive enrichment for antigen presentation signatures and negative enrichment for TNFα signaling and Oxphos metabolism. Similar findings were observed in BioFLIPI 2-3 FLs. Using CellChat analysis, we found a stronger interaction between malignant B cells and Tem exh and CTL Tem exh cells in BioFLIPI 4 and 2-3 vs BioFLIPI 1 tumors. This was linked to an increased strenght of MHCI-CD8 interaction and concordant decrease of MHCII-CD4. Notably, the suppressive BTLA-TNFRSF14 signaling axis was present in BioFLIPI 4 and 2-3 but not in BioFLIPI 1 FLs. This was accompanied by a decreased signaling through TNF/LTA-TNFRSF1B, CD80/CD86-CD28/CTLA4. Linking the BioFLIPI-specific immunogenicity to lymphomagenesis, we found that FL patients with BioFLIPI 4 had two-three folds higher risk of transformation to an aggressive lymphoma (12% vs 7%) or death (21% vs 3%) than those with BioFLIPI 1, suggesting that this immune dysfunction favors the expansion of a dominant tumor clone and promotes a more aggressive form of FL. Collectively, our findings demonstrate that BioFLIPI scores in FL reflect distinct patterns of tumor immunogenicity that shape the TME. Notably, high BioFLIPI scores are paradoxically associated with enhanced antigen presentation alongside a suppressed immune response. This suggests a sustained antigen-specific T cell response that may drive immune exhaustion, promote tumor progression, and ultimately lead to histologic transformation

Abstract Introduction: cBTKi have made a substantial impact in pts w/ MCL, but pts who develop PD while on treatment w/ cBTKi have historically had poor responses to subsequent lines of therapy (LOT). Brexucel, lisocel, and the non-covalent BTKi pirto have been approved in this population. While two RW studies have substantiated the benefit of brexucel, similar data for pirto are lacking. Accordingly, we aimed to evaluate the outcomes of pts treated w/ pirto in the RW setting. Methods: We performed a multi-center retrospective cohort study of adult pts w/ a diagnosis of MCL who experienced PD after any approved cBTKi and subsequently received pirto. Pts who received pirto w/ bridging intent and those who switched to pirto due to intolerance of cBTKi were excluded. The 95% exact binomial confidence intervals (CI) were calculated for overall response rate (ORR) and complete response rate (CRR). Progression-free survival (PFS) and overall survival (OS) were defined as the time from pirto start to PD or death, whichever occurred first, and the time from pirto start to death, respectively, and calculated w/ the Kaplan-Meier method. The log-rank test was used to compare survival curves. A multivariate (MV) Cox proportional hazard model was built to calculate adjusted hazard ratio (aHR). Analyses were performed w/ SAS, version 9.4. Results: Data on 111 pts w/ MCL treated across 21 institutions were collected. Median (mdn) age was 72 (range 33 – 93) years. Twenty-seven pts (24%) were female, 3 (3%) were Asian, 5 (5%) Black, 9 (8%) Hispanic, 86 (77%) White. Among the 53 (48%) pts w/ available MIPI-c at diagnosis, 28 (53%) pts were high-risk. Ki67 at diagnosis was available in 84 (76%) pts: of those, 58 (69%) had a Ki67 ≥30%, and 41 (49%) ≥50%. TP53 mutational status was available in 70 (63%) pts: 33 (47%) had documented TP53 mutation and 10/52 (19%) pts had a disease w/ complex karyotype. Pts had a mdn of 3 (range 1 – 9) prior LOT (n=106). Ninety-one pts (86%) received chemo-immunotherapy (CIT), 16 (15%) autologous stem cell transplant, 19 (18%) venetoclax (ven), 29 (27%) chimeric antigen receptor T-cell, 4 (4%) allogeneic stem cell transplant. For cBTKi, 39 (35%) pts received ibrutinib, 56 (50%) pts acalabrutinib, 33 (30%) pts zanubrutinib, and 17 (15%) pts received more than one cBTKi. The mdn time from the last dose of cBTKi to pirto start was 55 (range 0 – 2587) days, w/ 51 (46%) pts who switched from a cBTKi directly to pirto. Thirty (27%) pts had no response (stable disease or PD as best response) to cBTKi, and 40 (36%) pts had no response to the last LOT. Two (2%) pts received pirto in combination w/ CIT, 8 (7%) w/ an anti-CD20 monoclonal antibody (mAb), 11 (10%) w/ ven ± a mAb, while 86 (77%) pts as single agent. In 104 (94%) pts, pirto was given at full dose, 10 (9%) pts had a subsequent dose reduction. A total of 35 serious (grade ≥3) adverse events (AE) were documented in 27 (24%) pts: 4 (4%) pts had a serious bleeding AE, 5 (5%) pts a serious cardiac AE, 10 (9%) a serious GI AE, and 16 (14%) a serious infectious AE. Ninety-eight (88%) pts were evaluable for response. The ORR was 40% (95% CI 30% – 50%) w/ a CRR of 29% (95% CI 20%– 39%). At the last follow-up, 29 (26%) pts remained on pirto w/ a mdn treatment duration of 15.1 months (range 0.4 – 26). Fifty-eight (52%) pts died, 35 (78%) because of PD. At a mdn follow-up of 15.8 (range 0.4 – 26) months among survivors, the mdn PFS was 4.7 months (95% CI 3.3 – 8.2) and the mdn OS was 13 months (95% CI 9.2 – not available). Using the log-rank test, age (quartile groups), number of LOT (1-2 vs. 3-4 vs. 5+), time from cBTKi to pirto (quartile groups), Ki67≥30%, and high MIPI-C did not result in a statistically significant difference in PFS (p>0.05). Presence of TP53 mutation was associated w/ a non-statistically significant adverse trend in PFS (p=0.0585). No response to cBTKi and Ki67≥50% were associated w/ a statistically significant inferior PFS in log-rank test (p=<0.05), which persisted in a MV Cox regression model (aHR 2.4, 95% CI 1.4-4.2, and aHR 2.6, 95% CI 1.6-4.4, respectively). Conclusions: This is the first RW report on pirto in MCL pts. In this high-risk population, ORR to pirto was comparable to the BRUIN trial, while PFS was significantly worse, especially in pts w/ no response to cBTKi and w/ a high Ki67. However, prolonged remissions were seen in a subset of pts, suggesting that a better characterization of this population w/ durable benefit from pirto is needed.

Abstract Introduction: CD20xCD3 bispecific antibodies (BsAb) have been approved for use in relapsed/refractory (RR) large B-Cell lymphomas (LBCLs) with manageable toxicities. The main adverse events of clinical interest are cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). The risk factors for CRS and ICANS are not well understood. Knowledge of variables that contribute to increased risk may help clinicians identify and tailor management for high-risk patients (pts) and increase the comfort level for providers using these therapies in community practices. Methods: We performed a multicenter retrospective study at 21 US centers evaluating pts with RR LBCLs receiving commercially available epcoritamab (epco) or glofitamab (glofit) between 2023 and 2025. We obtained baseline characteristics, safety and efficacy outcomes. Univariate analysis was performed to identify associations between CRS, ICANS, and clinical variables of interest. Results: As of May 31, 2025, a total of 312 pts with RR LBCLs were treated with BsAb, Epco n=193 (62%), Glofit n= 119 (38%); median age 68; 63% male; 70% ECOG PS 0-1. Most common histologic type was diffuse large B-cell lymphoma, not otherwise specified (DLBCL, NOS) (n=239, 84%) followed by high-grade B-cell lymphoma (HGBL) (n=46, 16%). 179 pts (57%) were previously treated with chimeric antigen receptor T-cell (CAR-T) therapy, with 47% receiving CAR-T <6 months (mo) prior to BsAb. Among pts with prior CAR-T, CRS with CAR-T therapy of any grade occurred in 63%, with 26% ≥ grade 2. ICANS of any grade (G) occurred in 25% of pts (9.4% ≥ G3). Overall and complete response (ORR and CR) rates to BsAb were 51% and 29%, respectively. With a median follow up of 5 mo, median progression-free and overall survival (PFS and OS) were 2.3 and 7.3 mo, respectively. With BsAb treatment, CRS of any grade occurred in 117 (39%) patients: 24% G1, 8.7% G2, 4% G3, 1% G4 and 1% G5. The max grade CRS occurred most frequently after the third dose of epco (35%) and the first dose of glofit (23%). CRS was managed with additional steroids in 24% of pts and tocilizumab in 22%. 13% of pts experienced ICANS: 5.8% G1, 3.4% G2, 2% G3, 1% G4 and 0.3% G5. Factors that increased the risk for any grade CRS included: bulky disease ≥ 7.5 cm at time of BsAb treatment (OR 2.04, 95% CI 1.17 – 3.55, p = 0.012), elevated LDH (OR 2.56, 95% CI 1.45– 4.76, p = 0.002) and treatment with epco compared to glofit (OR 1.69, 95% CI 1.04- 2.77, p = 0.036). As G ≥2 CRS generally requires inpatient monitoring and management, we next compared the risk factors between pts with no CRS or G1 CRS and G ≥2 CRS. Factors associated with increased risk for high grade CRS included: bone marrow involvement by lymphoma (OR 3.47, 95% CI 0.97 – 11.3, p = 0.043), platelet count ≤ 75 (OR 2.46, 95% CI 1.21 – 4.87, p = 0.011), ≥ 2 extra nodal sites (OR 2.04, 95% CI 1.07 – 3.97, p = 0.032) and ≥G2 CRS with prior CAR-T (OR 3.35, 95% CI 1.13 – 9.97, p = 0.027). Factors that increased the risk for ICANS included: bulky disease (OR 2.67, 95% CI 1.28 – 5.49, p = 0.008), elevated Cr ≥ 1.5x ULN (OR 3.79, 95% CI 1.25 – 10.4, p = 0.012), elevated AST/ALT ≥ 3x ULN (OR 4.65, 95% CI 0.92 – 19.9, p = 0.042), low albumin (OR 2.85, 95% CI 1.49 - 5.5, p = 0.002), and co-occurrence of CRS with BsAb (OR 9.1, 95% CI 3.85- 25, p < 0.001). No other clinical variables including older age, histologic subtype, ECOG PS, B symptoms, IPI score, cell of origin or histologic subtype, baseline labs such as ALC, CRP, fibrinogen or D-dimer were significantly associated with CRS or ICANS risk. There was no difference in ORR or CR rates in patients who experienced CRS or ICANS. Conclusions: Our analysis of pts treated with commercial BsAb for LBCL shows an increased risk for CRS and ICANs based on clinical variables that are routinely obtained at baseline including tumor bulk, sites of disease, laboratory parameters, and history of prior CRS with CAR-T therapy. Differences in baseline populations receiving epco and glofit treatments in this real-world analysis have been previously reported (Brooks et al, Blood 2025) and the comparative risk for CRS between these treatments remains unclear. Future plans including multivariable analysis may allow for development of a predictive model to identify pts at high risk of CRS and ICANS with BsAb treatment, potentially leading to prospective clinical trials evaluating prophylactic interventions for high-risk pts.

Abstract Introduction: Epcoritamab (epco) and glofitamab (glofit) are bispecific antibodies (BsAbs) approved for the treatment of patients (pts) with multiply relapsed or refractory (r/r) large B-cell lymphoma (LBCL). Though response rates are relatively high, most patients (pts) eventually experience progression of disease (POD). We sought to investigate the treatment patterns and clinical outcomes following POD post-BsAb for r/r LBCL Pts, as this has not previously been described. Methods: We performed a multicenter retrospective study including 21 US centers evaluating pts with r/r LBCL receiving commercially available epco or glofit between 2023 and 2025. Baseline characteristics and outcomes were extracted from medical records. Efficacy and survival outcomes were assessed by site investigators and included overall response rate (ORR), complete and partial response (CR, PR) rates, progression-free survival (PFS) and overall survival (OS), analyzed using the Kaplan Meier method. Results: As of May 15, 2025, a total of 312 pts with r/r LBCLs were treated with BsAb, of whom a total of 168 (53.8%) pts experienced POD [104 of 193 (53.8%) treated with prior epco and 64 of 119 (53.8%) treated with prior glofit]. Pts with POD had a median age at BsAb start of 67 years (interquartile range [IQR] 58-76), most were male (68.4%), and the most common histology was diffuse large B-cell lymphoma not otherwise specified (n=122 [71.8%]). Sixty-seven of 168 pts (39.9%) with POD after BsAb had experienced primary refractory disease defined as failure to achieve PR or CR to frontline therapy. A total of 102 (60.7%) pts with POD to BsAb had received chimeric antigen receptor (CAR) T-cell therapy prior to BsAbs, with 33.3% of these pts being refractory to CAR T and 30.4% progressing within 6 months of CAR T-cell infusion. The median time to progression following BsAb start was 48 days. Following POD, 70 pts received no further anti-lymphoma therapy. Among 98 pts receiving subsequent therapy, 85 initially received systemic therapy and 13 initially received local therapy with radiation (concurrently with systemic therapy in 8 pts). The most commonly-used next line of systemic therapies included: loncastuximab tesirine in 19 pts (ORR 16.7%, all PR); commercial CAR T in 11 pts (ORR 50% [CR 36.4%, PR 18.2%); tafasitamab with lenalidomide in 7 (no responses); and other chemotherapy in 46 pts (ORR 27.6% [CR 24.1%]). The median follow-up time from POD was 9.2 months among survivors (95% confidence interval [CI] 7.8-13.3). Among those who initiated subsequent-line therapy following BsAbs, the median progression-free survival (PFS2) was 1.9 months (95% CI 1.5-2.4) and median overall survival (OS) from initiation of subsequent-line therapy was 3.9 months (95% CI 2.4-5.5). The estimated 1-year OS following initiation of next therapy was 12%. Conclusions: We report the outcomes of largest cohort of pts with POD post-BsAbs in r/r LBCL. Progression events occurred early after initiation of single agent BsAbs, and almost half of pts who progressed did not receive subsequent therapy. For those who received standard subsequent-line therapy after POD, response rates and survival outcomes were poor. Pts with POD after BsAB should be strongly considered for clinical trials of novel therapeutics or combination therapies.

Abstract Background: Despite the efficacy of covalent Bruton tyrosine kinase inhibitors (cBTKi) in R/R MCL, patients (pts) ultimately discontinue treatment due to intolerance or development of resistance and disease relapse. Pirtobrutinib is a highly selective, non-covalent BTKi that inhibits BTK with low nM potency throughout the daily dosing interval. Pirtobrutinib was safe and effective in the phase 1/2 BRUIN study in pts with R/R B-cell malignancies, including those previously treated with a BTKi. Pirtobrutinib is approved in the EU for adults with R/R MCL after prior treatment with a BTKi (EMA Conditional Approval, Oct 2023), and in the USA for adults with R/R MCL after ≥ 2 lines of systemic therapy, including a BTKi (FDA Accelerated Approval, Jan 2023).Here, we report the final results from the phase 1/2 BRUIN study (NCT03740529), with a follow-up period of up to 5 yrs, focusing on the efficacy and safety of pirtobrutinib in all R/R MCL pts. Methods: Pts with R/R MCL who received ≥1 prior lines of therapy (including BTKi) were eligible for treatment with pirtobrutinib monotherapy. Key endpoints included overall response rate (ORR), duration of response (DOR) and progression-free survival (PFS), all assessed by independent review committee (IRC) per Lugano 2014 criteria (presented here) and investigator, overall survival (OS), and safety. Pts were included across the range of doses evaluated in dose escalation and expansion (25-300 mg/day). A data cutoff on 27 January 2025 was utilized, with a median study follow-up of 17.5 months (range, 0.5-69.6). Results: Among the 166 pts with R/R MCL, 153 (92%) received the pirtobrutinib approved dose of 200 mg/day, 152 (92%) had received prior cBTKi, of which 128 (84.2%) discontinued any prior cBTKi due to progressive disease (PD), and 15 (9.9%) due to toxicity. The cBTKi-pre-treated pts had a median age of 70 yrs (range, 46-88), 52% had intermediate-risk and 28.3% had high-risk sMIPI scores. The median number of prior lines of therapy was 3 (range 1-9), with most pts having received a prior anti-CD20 antibody (96.7%) and chemotherapy (90.1%). Additional prior therapies included hematopoietic stem cell transplantation (21.7%; 19.7% auto and 4.6% allo), BCL-2 inhibitor (15.8%), CAR-T cell therapy (8.6%). As of the data cutoff, 11 (7.2%) pts who received a prior cBTKi and 6 (42.9%) cBTKi naïve pts remained on treatment. The cBTKi pre-treated pts had an ORR of 49.3% (95% CI, 41.1-57.6), including 15.8% complete responses (CR) (n=24) and 33.6% partial responses (PR) (n=51). The 75 responding pretreated pts had a median DOR of 21.6 months (95% CI, 9.2-27.2) at a median follow-up of 24 months. The ORR among 128 pts who had discontinued any prior cBTKi due to PD and 15 pts who discontinued due to toxicity was 43.0% and 93.3%, respectively. The median PFS and OS for cBTKi pre-treated pts were 5.6 months (95% CI, 5.3-9.2) and 23.9 months (95% CI, 17.3-51.5), respectively. Fourteen pts (9.2%) were censored for PFS due to subsequent anticancer therapy without documented PD, including 8 pts who received CAR-T. The cBTKi naïve pts (n=14) had an ORR of 85.7% (95% CI, 57.2-98.2), including 50.0% CR (n=7) and 35.7% PR (n=5). The 12 responding naïve pts had a median DOR of 42.7 months (95% CI, 25.8-NE) at a median follow-up of 43 months. The median PFS and OS in the cBTKi naïve pts were 44.6 months (95% CI, 16.7-NE) and not reached (95% CI, 33.5-NE), respectively. Among all R/R MCL pts (n=166), the most frequent treatment-emergent adverse events (TEAE), regardless of attribution, were fatigue (31.9%), diarrhea (22.9%), anemia (18.1%), and dyspnea (18.1%). The most common Grade ≥3 TEAE was neutropenia/neutrophil count decreased (13.3%), and the rate of Grade ≥3 infections was 21.1%. Grade ≥3 hemorrhage/hematoma (2.4%) and all-grade atrial fibrillation/flutter (3.6%) were infrequent. In total, 13 (7.8%) pts had a fatal TEAE, with 4 (2.4%) classified as infections. Overall, 8 pts (4.8%) had treatment-related AE leading to dose reductions, and 6 (3.6%) had treatment-related AE leading to pirtobrutinib discontinuation. Conclusion: Pirtobrutinib continues to demonstrate efficacy in pts with heavily pre-treated R/R MCL including both those who previously received a cBTKi and those who were BTKi-naïve. The safety profile of pirtobrutinib remained favorable with a low-rate of dose reductions/discontinuations due to drug-related toxicity. No new safety signals were identified after up to 5 yrs of follow-up.

Abstract Background and Significance: Polycythemia vera (PV) is a myeloproliferative neoplasm associated with pathologic erythrocytosis, most often driven by somatic mutations in the JAK2 gene. A key treatment goal is maintaining hematocrit (HCT) below 45% to reduce thromboembolic complications. Current standard of care for patients diagnosed with PV, including phlebotomy (PHL) and cytoreductive therapies (CRT), can be burdensome, may lead to intolerable adverse effects, and often are associated with symptoms of iron deficiency. DISC-3405 is an investigational, novel, humanized immunoglobulin (Ig)G1 monoclonal antibody that targets transmembrane serine protease 6 (TMPRSS6, also known as matriptase 2) to stimulate endogenous production of hepcidin, a peptide hormone secreted by hepatocytes and the key regulator of iron homeostasis. In a randomized, placebo-controlled study in healthy volunteers (DISC-3405-101), DISC-3405 administered subcutaneously at doses between 37.5-300 mg was well-tolerated, resulted in dose-dependent pharmacokinetic (PK) profiles, significantly increased hepcidin production with corresponding reductions in serum iron levels, and reduced HCT (Liu et al, EHA 2025, PS2207). DISC-3405 is being developed as a potential treatment for patients with PV requiring HCT reduction, regardless of baseline risk or concurrent CRT. Study Design and Methods: This is a multi-center, open-label, 52-week Phase 2 study enrolling up to 20 patients with PV in the United States to assess the safety, tolerability, PK, pharmacodynamics (PD), and therapeutic effect of DISC-3405 on PV disease control as evidenced by HCT reduction and PHL requirements. After an observation period of 4-12 weeks, participants will be treated and followed for 52 weeks and dosed up to 300 mg every 2 weeks. After 52 weeks, participants can continue in an optional 2-year continuation phase where long-term safety and efficacy will continue to be assessed. The main efficacy endpoints of the study include the proportion of participants achieving therapeutic response, defined as absence of PHL eligibility; number of PHLs during the treatment period; and proportion of participants with HCT values <45% throughout the study. PHL eligibility is defined as (1) HCT ≥45% and ≥3% (absolute change) of pre-treatment values or (2) HCT >48%. Eligible participants include adults 18 or older who meet the 2022 World Health Organization diagnostic criteria for PV. Clinically acceptable laboratory values include HCT <45% prior to Day 1 (dosing) or HCT <48% if followed by a PHL within 2 weeks prior to first dose of study drug, white blood cells 4000/μL to 20,000/μL (inclusive), and platelets 100,000/μL to 1,000,000/μL (inclusive). Participants should have at least 3 PHL in 26 weeks or 5 PHL in the 52 weeks prior to screening, and at least 1 PHL within 12 weeks prior to screening. Participants receiving CRT must have been on the therapy for at least 6 months and on a stable PV treatment regimen, including hydroxyurea, interferon, or ruxolitinib, for at least 2 months. Participants treated with only PHL must have stopped CRT 6 months before screening. Key exclusion criteria include participants that require PHL at HCT levels <45%, clinically significant thrombosis within 2 months prior to study treatment, active or chronic bleeding, estimated glomerular filtration rate of <30 mL/min/1.73 m2, and history of invasive malignancies within the last 5 years, except localized cured prostate cancer and cervical cancer, or other malignancies deemed acceptable in discussion with the Sponsor. The study will enroll participants from approximately 15-20 sites in the United States. Additional details can be found at https://clinicaltrials.gov/study/NCT06985147.

Abstract Introduction: Standardized reporting of clinical trials results for MDS is essential to improve clinical interpretation and cross-study comparison. However, reporting of patient characteristics, response criteria, and endpoints in publications is often inconsistent; there is no systemic analysis of MDS trial reporting available. We conducted a systematic review of published MDS trial manuscripts on behalf of the international consortium for MDS (icMDS) to assess variability in reporting practices. Methods We searched ClinicalTrials.gov to identify all clinical trials registered for adults (≥18 years) with MDS that reported results between 2015-2024. Clinical trials that included acute myeloid leukemia (AML) or MDS/myeloproliferative neoplasms (MPN) were included if they enrolled ≥5 MDS patients. We excluded trials without an MDS cohort; non-therapeutic trials; trials focused on transplant interventions; or those which enrolled solid malignancies or other hematologic malignancies (chronic myeloid leukemia or lymphoid diseases). Finally, trials were required to have a manuscript available on Larvol, PubMed, or Google Scholar. Trials were categorized by disease risk (lower-risk [LR] vs. higher-risk [HR]) and trial phase (early phase [EP] vs. late phase [LP]). Results We identified 502 MDS trials on ClinicalTrials.gov, of which 351 did not meet inclusion criteria and 79 lacked a manuscript. A total of 72 trials (32 EP, 40 LP) with 80 publications (34 EP, 46 LP) were analyzed. Frequently reported baseline characteristics included age (100% EP, 100% LP), disease risk (74% EP, 74% LP), Eastern Cooperative Oncology Group performance status (85% EP, 72% LP), prior treatments (71% EP, 67% LP), and RBC transfusion dependency (32% EP, 70% LP). Less frequently reported characteristics included blood counts (hemoglobin [Hb; 38% EP, 54% LP], platelet count [38% EP, 54% LP], neutrophil count [24% EP and LP]) and bone marrow blasts (29% EP, 43% LP). Although disease risk was widely reported, definitions varied: IPSS and IPSS-R were each reported in 54% of manuscripts, while IPSS-M appeared in only 3%. Cytogenetic risk was separately reported in 39% of manuscripts (38% EP, 39% LP), and mutational data in 45% (47% EP, 43% LP). Responses per IWG 2006 criteria were reported in 84% of manuscripts. The primary endpoint involved safety/tolerability in 85% of EP manuscripts, though definitions were variable; recommended phase 2 dose was the most common (26% of EP manuscripts). In LP trials, primary endpoints were risk-specific: transfusion independence (TI) in 77% of LR, overall response rate (ORR) in 28% of HR, and complete remission (CR) or overall survival (OS) in 22% of HR. In HR manuscripts, CR was reported in 100%, ORR in 73%, hematologic improvement (HI) in 48%, RBC-TI in 23%, and OS in 80%. However, seven different definitions were used for ORR: CR + marrow CR + partial remission + HI per IWG 2006 was most common (35%). Event-free survival was reported in 25%; progression-free survival and relapse-free survival in 13%; and leukemia-free survival in 5%. Early mortality rate was reported in 35% (18% EP, 56% LP) and transplant rate in 58% (50% EP, 67% LP). Only 47% of HR and 90% of LR manuscripts identified HI-eligible patients. In LR-MDS, RBC-TI was reported in 72% of manuscripts but used six definitions. The most common were RBC-TI ≥8 weeks at any time during treatment (24%), ≥8 weeks within 28 weeks of treatment (13%), ≥8 weeks with Hb increase ≥1.0 (4%), ≥12 weeks with Hb increase ≥1.5 (4%), and ≥16 weeks within 24 weeks of treatment (12%). The remainder did not report RBC-TI, did not define it, or used a custom definition not used in another trial. HI was reported in 80% of LR papers with most of those reporting HI using IWG 2006 criteria (90%). Conclusion Reporting of baseline characteristics, response criteria, and outcomes is inconsistent in MDS clinical trials, with wide variability in response definitions, including ORR and TI. This heterogeneity limits interpretability, hampers historical comparisons and may obscure efficacy signals. Our findings highlight the need for standardized reporting guidelines to ensure clarity and consistency in MDS trial publications. As a next phase of this effort, we will conduct a formal Delphi process among icMDS experts to establish consensus recommendations for minimal and optimal MDS clinical trial reporting in manuscripts by disease risk (LR/HR) and trial phase (EP/LP).

Abstract Introduction: Graft Failure (GF) is a rare but devastating outcome of HCT. Primary GF (PGF), defined as a failure of neutrophil recovery by Day+28, is straightforward to diagnose. Diagnosing secondary GF (SGF) is more challenging, with its broad time-range, multiple confounding diagnoses, and lack of predictive biomarkers. In BMT CTN1703/1801, we analyzed patients receiving RIC HCT for heme malignancies with either Tac/MTX (n=159) or PT-Cy (n=165) GVHD prophylaxis. SGF was defined as donor chimerism <5% after initial donor engraftment. With Tac/MTX, there were 3 PGF and 1 SGF diagnoses. With PT-Cy, there were 4 PGF and 6 SGF. Median SGF diagnosis was Day +64 (range: Day+28-215). There were too few Tac/MTX patients to analyze SGF, but sufficient events with PT-Cy. To identify PT-Cy SGF predictors, we leveraged lymphocyte, T, B, and NK cell reconstitution analysis. In SGF we found an early, profound deficit in the reconstitution of all major lymphocyte populations, including total lymphocytes, T, B, and NK cells, as early as Day+28. This enabled the modeling of a SGF risk classifier based on the Absolute Lymphocyte Count (ALC). Methods: Clinical ALC measurements were performed on all SGF patients (n=6) and on non-GF controls with ALCs available (146 of 155 non-GF patients). Flow cytometry was performed on all PT-Cy SGF patients (n = 6) and from a subset of non-GF controls (n = 18: controls were chosen as patients without relapse or severe GVHD, to reduce confounders introduced by immunologic interventions, and for whom all samples, including from the graft infusion, were available). T, B, and NK counts, as well as T cell subsets, were compared (using Welch's T test) on Days 7, 14, 21, 28, 42, 63, 98, 180, 270, 365, 730, with SGF patients censored on the day of GF diagnosis. To interrogate the optimal ALC cutoff, the cumulative incidence of SGF was computed at Days +28 and +42, with death without GF as a competing risk. Results: We have previously demonstrated that, compared to Tac/MTX, PT-Cy patients exhibited an early decrease in reconstitution of all T cell populations (with normal NK and B cell reconstitution). Here we focused specifically on PT-Cy patients with or without SGF. Graft CD34 counts/kg were not different between SGF patients and non-GF patients (mean CD34/kg = 1.38 x10e6 (SGF) vs 0.67 x10e6 (non-GF, p = 0.61) However, even amidst the overarching early suppression in T cell reconstitution with PT-Cy, SGF patients could be easily distinguished from the larger PT-Cy cohort, based on more profound deficits in ALC, T, B and NK cells reconstitution, measured using 2 strategies: (1) SGF patients demonstrated significant early (Day +28) quantitative defects in the reconstitution of the ALC (mean +/- SEM 262+/-32 cells/µL (non-GF) vs 60 +/- 25 (SGF, p<0.0001), CD4 T cells (62 +/- 12 cells/µL vs 19+/-15, p=0.048), CD8 T cells (15 +/-3 cells/µL vs 3.5 +/-1 p=0.0009), all CD8 T cell subpopulations, as well as NK cells (116+/-31 cells/µL vs 2.9+/-1.4 cells/µL, p= 0.002) and B cells (3.5 +/-1.4 cells/µL vs 0.16+/-0.07 p =0.03). (2) In SGF, there was a significant deficit in the rate of rise of all major lymphocyte populations between Days 28-42-60 vs non-GF, including CD4 T cells (p<0.0001), CD8 T cells (p = 0.0002), B cells (p<0.0001), and NK cells (p =0.048). These discoveries suggested that a classifier could be identified to risk-stratify patients for SGF. We explored an ALC cutpoint, amenable to standard clinical lab analysis. A statistically significant threshold was identified at both Days+28 and +42, with Day+42 being most predictive: A threshold of 120 cells/µL was identified as optimal, with landmark analysis documenting a SGF rate of 34.7% below the cutpoint, and SGF of 1% above it (HR = 45.9, 95% CI 5.7 - 366). Conclusions: Despite the small number of events, PT-Cy patients with SGF demonstrated a distinctive reconstitution trajectory that encompassed an early, substantial, and sustained deficit in all lymphocyte counts, as well as a lack of their longitudinal expansion. This enabled the discovery of a candidate ALC biomarker cutpoint at Day+42 that could distinguish patients who were more likely to develop SGF. If confirmed, these data could generate a predictive biomarker for SGF, which would enable the design of trials evaluating early interventions (e.g. CD34+ boosts, DLI, modification of immunosuppression) to improve outcomes for these patients.

Abstract Background: Dissemination and implementation science (D+I) efforts often begin after clinical trial (CT) efficacy data are available. However, delaying this work limits opportunities to identify barriers and facilitators that can enhance adoption of evidence-based practices. Integrating D+I during trial development, activation, and conduct supports more timely, effective, and scalable implementation. The Blood and Marrow Transplant Clinical Trials Network (BMT CTN) includes >125 centers, conducting transplant and cellular therapy (TCT) trials with practice-changing potential, with >17,000 patients enrolled since 2001. Data from Center for International Blood and Marrow Transplant Research (CIBMTR) provides a way to measure real-world adoption. With this comprehensive structure in place, the BMT CTN launched a D+I Committee that established a D+I process to better understand uptake of CT findings and to leverage that information to promote adoption. Methods: Informed by established D+I frameworks, a structured, cyclical process to integrate implementation considerations spanning the CT lifecycle was developed. A multidisciplinary team including experts in D+I, clinicians, and investigators iteratively refined the proposed D+I algorithm. The process begins upstream when a trial concept is approved to move forward, it is shared with the D+I Committee for initial assessment. This includes a landscape review for studies in development using CIBMTR data, literature, and expert experience. The Committee then reviews the developing protocol with the BMT CTN protocol team to proactively identify implementation barriers and facilitators to implementation in real-world settings and outline plans for dissemination. The Committee also provides recommendations for integrating relevant implementation data collection and analyses within the protocol. After study completion, both clinical efficacy and implementation outcomes are analyzed, followed by active dissemination. Additional assessment using surveys, qualitative methods, and CIBMTR data occurs after dissemination to understand adoption. Insights gathered also inform further refinement of the process. Tools and templates are in development to build capacity and ensure consistency for Committee members. Results: To date, the Committee has published three peer-reviewed articles addressing implementation implications of three BMT CTN trials (PMC7735536, PMC8578257, PMC9364468) and a fourth is in press. Using the designed D+I process flow, a current effort used a survey sent to US CIBMTR centers, to evaluate factors influencing the implementation of results of the BMT CTN 1703 trial of post-transplant cyclophosphamide as graft-versus-host disease (GvHD) prophylaxis and assessed dissemination and adoption considerations for the upcoming BMT CTN 2203 CT of ruxolitinib as GvHD prophylaxis. CIBMTR data is being analyzed to demonstrate practice patterns before, during, and after BMT CTN 1703 study completion. This effort has allowed for further refinement of the BMT CTN D+I process flow and has highlighted critical opportunities for incorporating dissemination and implementation objectives and endpoints into BMT CTN protocols. We also used the process to guide a review of severe aplastic anemia treatment gaps and ongoing studies. This review underscored how proactive transplant and non-transplant stakeholder engagement and early implementation planning, core elements of this process, can bridge evidence to practice and advance access to care. A complementary survey on current practice patterns in severe aplastic anemia is ongoing. Conclusions: With the existing structure of the BMT CTN and associated practice registry of the CIBMTR, the BMT CTN D+I Committee developed a systematic process to build D+I considerations into trial workflows to increase real-world impact. This process aims to ensure that barriers to uptake of trial results can be identified and addressed appropriately, improving care quality for patients undergoing TCT.