Forsyth, Cecily

Abstract Introduction: The introduction of the Bruton tyrosine kinase inhibitor acalabrutinib combined with bendamustine and rituximab (ABR) as first-line (1L) therapy for mantle cell lymphoma (MCL) in older patients (pts) is reshaping the approach to treatment sequencing in this disease. The primary analysis of the phase 3 ECHO trial (NCT02972840) with data cutoff Feb 15, 2024 (median time on study 44.9 mo) demonstrated improved progression-free survival (PFS) with ABR vs placebo plus BR (PBR; hazard ratio [HR] 0.73; 95% confidence interval [CI] 0.57–0.94; P=0.0160) in pts ≥65 y with treatment-naive (TN) MCL. Here we present updated results after 50 mo of follow-up, including time to next treatment 2 (TTNT2; ie, initiation of third-line [3L] therapy). Methods: Pts aged ≥65 y with TN MCL and ECOG performance status ≤2 were randomly assigned 1:1 to receive ABR or PBR. Randomization was stratified according to geographic region and simplified MIPI score. BR was given for 6 cycles followed by rituximab maintenance for 2 y in pts achieving a partial or complete response (CR). Acalabrutinib (100 mg twice daily) or placebo was administered at study start until progressive disease (PD) or unacceptable toxicity. Crossover to acalabrutinib was permitted at PD. The primary endpoint was PFS per independent review committee. TTNT2, which was used as a surrogate for PFS2 (time from initial treatment to second disease progression), was defined as time from randomization to second subsequent (3L) antilymphoma therapy after discontinuation of randomized treatment or death. Results: In total, 299 pts were randomized to each arm; median age was 71 y. At data cutoff (February 15, 2025), median (range) time on study was 51.86 (0.03–93.04) mo and median (range) follow-up through reverse Kaplan-Meier method for PFS was 60.8 (0–88.5) mo. Median TTNT2 was not reached (NR) in the ABR arm and 73.8 mo in the PBR arm, establishing a 24% reduction in the risk of initiating 3L therapy or death with ABR vs PBR (stratified HR 0.76; 95% CI 0.59–0.98). In total, 33 (11.0%) and 100 (33.4%) pts received second-line [2L] treatment (median time to 2L therapy, 26.3 vs 19.6 mo) and 10 (3.3%) and 37 (12.4%) received 3L treatment in the ABR and PBR arms, respectively. When COVID-19 deaths were censored (in alignment with prespecified analyses from the primary study), the HR further improved (stratified HR 0.67; 95% CI 0.50–0.89; median TTNT2 NR in any arm). In total, 71.6% and 78.3% of pts discontinued acalabrutinib and placebo, respectively; the most common reasons (>5%) for discontinuation were adverse events (AEs; 44.5%, ABR; 32.4%, PBR) and objective PD (12.7%, ABR; 30.8%, PBR). Median PFS was 72.5 and 47.8 mo in the ABR and PBR arms, respectively (stratified HR 0.68; 95% CI 0.53–0.87; P=0.002). In total, 108 (36.1%) and 116 (38.8%) pts in each arm died; median overall survival (OS) was NR in both arms (stratified HR 0.87; 95% CI 0.67–1.13), with a 36-mo OS rate of 73.8% with ABR vs 68.3% with PBR. With 1 additional year of follow-up since the primary analysis, rates of grade ≥3 AEs and serious AEs in the ABR arm were comparable to previously reported rates, indicating that prolonged acalabrutinib exposure does not appear to result in cumulative toxicities. Three new cases of grade 3/4 neutropenia were reported, with no marked changes in the rates of grade ≥3 or serious infections. The rate of grade ≥3 cardiac events remained consistent with the primary analysis. In the ABR arm, 1 new case of grade 3/4 atrial fibrillation and 1 new case of grade 3/4 hypertension were reported. Rates of thrombocytopenia, major hemorrhage, and ventricular tachyarrhythmia remain unchanged. Conclusion: In this updated analysis of the ECHO trial, despite crossover to acalabrutinib being permitted in the PBR arm, fewer pts in the ABR arm were in need of subsequent treatment (2L and 3L), with longer TTNT2 in the ABR arm. These results suggest that 1L treatment with ABR provides a 24% reduction in risk of initiating 3L therapies or death. Further follow-up has demonstrated that ABR offers improved efficacy (ie, PFS) vs PBR, with no long-term safety concerns with acalabrutinib maintenance. The updated safety findings further support the favorable benefit–risk profile of acalabrutinib in TN MCL. Altogether, these data support the potential of acalabrutinib in combination with BR as 1L treatment, rather than in later lines, to modify long-term treatment outcomes in pts with TN MCL.

PURPOSE The combination of the Bruton tyrosine kinase inhibitor ibrutinib with bendamustine-rituximab for first-line treatment of mantle cell lymphoma (MCL) prolonged progression-free survival (PFS), but without improvement in overall survival (OS), likely because of toxicity. Acalabrutinib was shown to be efficacious and less toxic than ibrutinib in a head-to-head trial in chronic lymphocytic leukemia and therefore might lead to better outcomes in MCL. METHODS Patients 65 years and older with previously untreated MCL received acalabrutinib (100 mg twice daily) or placebo (until disease progression or unacceptable toxicity), plus six cycles of bendamustine (90 mg/m 2 once daily; days 1 and 2) and rituximab (375 mg/m 2 as a single dose; day 1) followed by rituximab maintenance in responding patients for 2 years. Crossover to acalabrutinib at disease progression was permitted. The primary end point was PFS per the independent review committee; overall response rate and OS were secondary end points. RESULTS In total, 598 patients were randomly assigned, with 299 in each arm. At a median follow-up of 49.8 months using the reverse Kaplan-Meier method, the median PFS was 66.4 months in the acalabrutinib arm and 49.6 months in the placebo arm (hazard ratio [HR], 0.73 [95% CI, 0.57 to 0.94]; P = .0160). Benefit was seen across all subgroups, including those with high-risk features. Overall response/complete response rates were 91.0%/66.6% and 88.0%/53.5% in the acalabrutinib and placebo arms, respectively. OS was not significantly different (HR, 0.86 [95% CI, 0.65 to 1.13]; P = .27). Grade 3 or greater adverse events were reported in 88.9% and 88.2% in the acalabrutinib and placebo arms, respectively. CONCLUSION The combination of acalabrutinib with bendamustine-rituximab significantly improved PFS. Clinical benefit of acalabrutinib with bendamustine-rituximab was achieved with manageable toxicity.

Introduction Relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) is very aggressive, with a historically low complete response (CR) rate (Blood. 2017; 130[16]:1800-1808). Recent research has focused on achieving complete and durable responses in this population, which translate to improvements in overall survival (OS) and progression-free survival (PFS). Results from the randomized, global, phase 3 ECHELON-3 study (NCT04404283) demonstrated a statistically significant and clinically meaningful improvement in OS, PFS, and objective response rate with brentuximab vedotin (BV) combined with lenalidomide (Len) and rituximab (R; BV+Len+R) vs placebo+Len+R in patients (pts) with R/R DLBCL after ≥2 prior systemic therapies. Here, we present subgroup analyses in pts with a best overall response (BOR) of CR (n=67). Methods Pts in the study were randomized (1:1) to receive BV (1.2 mg/kg) or placebo every 3 weeks, in combination with R (375 mg/m2) and Len (20 mg) once daily. In these subgroup analyses, eligible pts had a BOR of CR and some ended study treatment and received any subsequent anticancer therapy. BOR was assessed by investigators according to the Lugano 2014 classification. Duration of response was defined as the time from the start of the first documented CR to the first documented tumor progression per Lugano 2014 or death. Pts who initiated a subsequent nonpalliative anticancer therapy were censored at the most recent prior response assessment. Subsequent nonpalliative anticancer therapies were defined as any systemic therapy received after the end of study treatment. P values are descriptive. Results Of the 112 pts in the BV+Len+R group, 45 (40.2%) had a BOR of CR. Of the 118 pts in the placebo+Len+R group, 22 (18.6%) had a BOR of CR. The median duration of CR was 18.9 months (95% CI, 11.1 months-not estimable [NE]) with BV+Len+R vs not reached (NR) with placebo+Len+R (hazard ratio [HR], 0.527; 95% CI, 0.200-1.389; P=.1891). The median time to CR was 1.58 months (range, 1.2-7.3 months) with BV+Len+R and 1.61 months (range, 0.7-4.6 months) with placebo+Len+R. With a median follow-up of 14.3 months, the median OS in pts with a BOR of CR was 31.5 months (95% CI, 20.3 months-NE) in the BV+Len+R group vs NR in the placebo+Len+R group (HR, 1.044; 95% CI, 0.331-3.298; P=.9407). Median PFS in pts with a BOR of CR was 21.5 months (95% CI, 12.6 months-NE) in the BV+Len+R group vs NR (95% CI, 5.4 months-NE) in the placebo+Len+R group (HR, 0.6333; 95% CI, 0.256-1.567; P=.3198). Results of NR in the placebo+Len+R group are likely attributable to limited follow-up and small sample size. Additional data on baseline characteristics of pts who had CR will be presented. Of the 45 pts with CR in the BV+Len+R group, 42 (93.3%) received no subsequent anticancer therapy. Of the 22 pts with CR in the placebo+Len+R group, 17 (77.3%) received no subsequent anticancer therapy. Conclusions BV doubled the CR rate in pts with R/R DLBCL compared with placebo, and outcomes in pts with CR were durable, with only 6.7% of pts treated with BV+Len+R receiving subsequent systemic anticancer therapy, compared with 22.7% of pts treated with placebo+Len+R receiving subsequent therapy. Overall, BV+Len+R demonstrated a survival benefit in the ECHELON-3 study and is a promising option to achieve complete and durable responses in third- or later-line therapy for pts with R/R DLBCL.

Introduction: The primary analysis of the phase 3 ECHO trial (NCT02972840) demonstrated that acalabrutinib plus bendamustine-rituximab (ABR) significantly improved progression-free survival (PFS) vs placebo plus bendamustine-rituximab (PBR) in older patients (pts) with previously untreated mantle cell lymphoma (MCL) (Wang et al. EHA 2024, Abstract #LB3439). Here we present additional efficacy and safety results from the ECHO trial. Methods: Pts aged ≥65 years (y) with previously untreated MCL and ECOG PS ≤2 were randomly assigned 1:1 to receive ABR or PBR. Acalabrutinib (100 mg twice daily) or placebo was administered until progressive disease (PD) or unacceptable toxicity. Induction with BR was administered for 6 cycles followed by rituximab maintenance (A±R maintenance, cycles 7-30) in pts achieving a partial or complete response (PR or CR). Pts progressing on PBR could cross over to receive acalabrutinib monotherapy. PFS (primary endpoint) was assessed by independent review committee. Minimal residual disease (MRD) negativity rate (10-5) was assessed in peripheral blood (every 24 weeks [wks], at CR, and at PD) and bone marrow (at CR) by NGS-based ClonoSEQ assay (Adaptive Biotechnologies). Results: Among the 598 pts randomized to ABR or PBR (299 in each arm), high-risk baseline characteristics included high-risk simplified MIPI score in 24.1% and 24.4%, blastoid histology in 8.7% and 6.7%, pleomorphic histology in 5.0% and 6.0%, centrally tested Ki-67 ≥30% in 46.5% and 49.2%, and known TP53 mutation in 7.4% and 9.7%, respectively. PFS hazard ratios (HRs) for subgroups were 0.78 (95% confidence interval [CI] 0.51-1.19) in pts with high-risk simplified MIPI score, 0.68 (95% CI 0.29-1.58) in pts with blastoid histology, 0.64 (95% CI 0.25-1.66) in pts with pleomorphic histology, 0.69 (95% CI 0.49-0.98) in pts with Ki-67 ≥30%, and 0.88 (95% CI 0.42-1.78) in pts with known TP53 mutation. In the ABR arm, median PFS was 22.2 months (mo) among pts who discontinued acalabrutinib during induction for reasons other than PD or death, 29.4 mo in pts who discontinued acalabrutinib during A±R maintenance (cycles 7-30) for reasons other than PD or death, and not reached in pts who received acalabrutinib for 31 cycles or more. Among evaluable patients who were MRD negative at the end of induction (24 wks), the rate of conversion to MRD positive during maintenance was lower in the ABR arm (5.85%; n=11/188) than in the PBR arm (15%; n=26/171). Conversely, among evaluable pts who were MRD positive at the end of induction (24 wks), 37.5% (n=3/8) in the ABR arm and 20% (n=3/15) in the PBR arm converted to MRD negative during maintenance. Overall rates of AEs were similar in each arm during induction, but were higher in ABR during A±R maintenance (cycles 7-30) and more so in the monotherapy phase (cycle 31+). Grade ≥3 TEAEs (ABR vs PBR) were 70.0% vs 68.7% during induction, 64.9% vs 62.9% during A±R maintenance (cycles 7-30), and 57.0% vs 45.3% during monotherapy (cycle 31+). Similarly, rates of TEAEs leading to discontinuation of acalabrutinib/placebo were 8.1% vs 8.8% during induction, 23.9% vs 19.0% during A±R maintenance (cycles 7-30), and 25.9% vs 13.7% during monotherapy (cycle 31+). Exposure-adjusted incidence rates per 100 person-years reduced the difference between ABR and PBR for clinically relevant TEAE rates (32.6 vs 29.3 for grade ≥3 serious TEAEs; 4.2 vs 4.0 for grade 5 TEAEs; 15.5 vs 12.4 for TEAEs leading to acalabrutinib/placebo discontinuation), possibly due to longer median exposure to acalabrutinib (28.6 vs 24.6 mo). Conclusion: Acalabrutinib in combination with BR provides a significant PFS benefit in pts with previously untreated MCL, including those with high-risk features. Furthermore, the addition of acalabrutinib to BR provided a greater PFS effect among pts in the ABR arm with the longest exposure to acalabrutinib. The PFS improvement may be partially driven by the contribution of acalabrutinib to sustained MRD-negative status and deepened responses after the end of induction. ABR provides this clinical benefit without excess toxicity as shown by attenuated differences between arms in exposure-adjusted incidence rates, suggesting that higher AE rates in the ABR arm are likely due in part to the longer duration of acalabrutinib treatment vs placebo. These data emphasize the benefits of acalabrutinib in frontline MCL treatment in high-risk pts and the additional benefit of continuous therapy.

Abstract Background: It has been known for approximately 19 years that germline mutations in RUNX1, lead to familial platelet disorder with predisposition to myeloid malignancy (FPD-MM, OMIM 601399). Since that time researchers have identified a broad range of different RUNX1 mutations, in over 100 families. In large families, the diagnosis of malignancy shows variable penetrance among family members with the same mutation; some carriers of RUNX1 mutations do not develop malignancy. The causes of this heterogeneity are currently not known, complicating counselling and risk analysis for individual carriers. Recent advances in genetic sequencing technology applied by many FPD-MM research groups around the world have highlighted their value in understanding the somatic genetic changes that are associated with development of malignancies in germline RUNX1 mutation carriers. Collectively this information could lead to powerful insights essential for more precise risk assessment, monitoring, and therapeutic intervention. Specifically, a growing catalogue of somatic mutations associated with germline RUNX1 malignancy offers the opportunity for informed monitoring of asymptomatic RUNX1 carriers for additional high-risk somatic mutations, in turn providing the possibility for early therapeutic intervention to arrest the leukemic process. The challenge in advancing these goals for FPD-MM is the relative rarity of the disorder in individual populations. Global data sharing in a highly interactive FPD-MM research community offers a solution to this problem that benefits all patients world-wide. Aims: To create a global RUNX1 network through identifying and contacting researchers and clinicians with known and novel germline RUNX1 families, seeking their collaboration to share genomics data. To create a RUNX1.db portal to collectively house and analyse genomics data from germline RUNX1 carriers, with associated phenotype and clinical information, such that researchers have an ongoing means by which to combine their data with those generated by other groups around the world. Methods: RUNX1 network : Through existing collaborative networks, a systematic review of the literature, and referrals from initial contacts, we have identified a global network of researchers managing FPD-MM cases and families. RUNX1.db: We have adapted a custom-built variant analysis platform, VariantGrid, that is a visual web application and database designed to help scientists manage and analyse DNA variants that can be used to aggregate and analyse multiple datasets. Results: Preliminary analysis of aggregated data from the literature suggests there are features of germline RUNX1 syndrome that can be ascertained. These include frequent somatic mutation of RUNX1 in malignancy development, as well as mutations in genes associated with clonal hematopoiesis that may precede development of overt leukemia. This analysis also suggests that different types of germline RUNX1 mutations may be associated with different combinations of somatic mutations in the tumour. To further this analysis, we have identified over 70 groups internationally that either manage RUNX1 families or have identified potential germline carriers through genomics initiatives. This represents a large and growing resource for both scientific studies and clinical programs to benefit individuals with FPD-MM. Many of these groups have generated NGS data sets from patient samples which will be available for analysis through this portal. Further details and activities of the network, and results from the genomics aggregation database will be presented. Conclusion: We have created a global RUNX1 network, aggregated their data, and generated a RUNX1.db genomics portal for the continuous curation of genomics data from germline RUNX1 carriers. A preliminary analysis has already identified specific features of germline RUNX1 mutated malignancies that have clinical importance. Ongoing scientific and clinical studies through the RUNX1 network will enhance the power of aggregated data analysis, with RUNX1.db providing a central link, driving new insights that benefit patients. Disclosures Natsoulis: Imago BioSciences, Inc.: Consultancy, Equity Ownership. Guzman:Cellectis: Research Funding. DiNardo:Bayer: Honoraria; Karyopharm: Honoraria; Celgene: Honoraria; Agios: Consultancy; Medimmune: Honoraria; Abbvie: Honoraria. Borate:Novartis: Consultancy; Agios: Consultancy. Wei:Amgen: Honoraria, Other: Advisory committee, Research Funding; Pfizer: Honoraria, Other: Advisory committee; Celgene: Honoraria, Other: Advisory committee, Research Funding; Abbvie: Honoraria, Other: Advisory board, Research Funding, Speakers Bureau; Servier: Consultancy, Honoraria, Other: Advisory committee, Research Funding; Novartis: Honoraria, Other: Advisory committee, Research Funding, Speakers Bureau. Dokal:MRC, Bloodwise, Telomerase Activator Sciences: Research Funding; The Gary Woodward Dyskeratosis Congenita Trust: Membership on an entity's Board of Directors or advisory committees; Action Medical Research, European School of Haematology: Membership on an entity's Board of Directors or advisory committees; Barts and The London School of Medicine and Dentistry, Queen Mary University of London,: Employment, Research Funding; Telomerase Activator Sciences: Research Funding; Barts and The London, Queen Mary University of London: Employment; Gary Woodward Dyskeratois Congenita Trust: Membership on an entity's Board of Directors or advisory committees. Hiwase:Novartis: Research Funding; Celgene: Research Funding. Branford:Cepheid: Honoraria; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Qiagen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Kramer:Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Bayer: Research Funding; Daiichi Sankyo: Consultancy. Owen:Merck: Honoraria; Teva: Honoraria; AbbVie: Research Funding; Pharmacyclics: Research Funding; Janssen: Honoraria, Research Funding; Celgene: Research Funding; AstraZeneca: Honoraria, Research Funding; F. Hoffmann-La Roche Ltd: Honoraria, Research Funding. Fitzgibbon:Epizyme: Consultancy, Research Funding; Gilead: Consultancy. Rienhoff:Imago BioSciences, Inc.: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Kurokawa:Astellas Pharma: Research Funding; Sumitomo Dainippon Pharma: Research Funding; Nippon Sinyaku: Honoraria, Research Funding; Kyowa Hakko Kirin: Honoraria, Research Funding; Eizai: Research Funding; MSD: Honoraria, Research Funding; Ono Pharmaceutical: Honoraria, Research Funding; Pfizer: Research Funding; Takeda Pharmaceutical: Research Funding; Otsuka Pharmaceutical: Research Funding; Teijin Pharma: Research Funding; Chugai Pharmaceutical: Research Funding.