Sancho, Juan-Manuel

7011 Background: Up to 40% of pts with diffuse large B-cell lymphoma (DLBCL) will relapse or have refractory disease following 1L treatment (Tx) with SOC chemoimmunotherapy regimens R-CHOP or Pola-RCHP. High risk (HR) populations include those with International Prognostic Index (IPI) score 3–5 and IPI 1–2 with either ≥1 lesion ≥7 cm or baseline LDH >1.3×ULN. GOLCA is a potential, first-in-class, oral CELMoD designed for the Tx of lymphoma, with preferential distribution to lymphoid organs and enhanced activity in lymphoma cell lines. GOLCA induces rapid and deep degradation of Ikaros and Aiolos, leading to direct cell killing and immunomodulatory activity. GOLCA 0.4 mg + R-CHOP has shown promising safety, a ≥90% minimal residual disease (MRD) negativity rate, and durable efficacy (24-mo PFS, 79%) in 1L a-BCL (Nowakowski et al, ASH 2025, 476) and is being evaluated in the Phase (Ph) 3 study GOLSEEK-1 (NCT06356129). We report initial Ph1b results with GOLCA + Pola-RCHP in 1L a-BCL. Methods: Pts aged ≥18 y with ECOG PS ≤2, IPI 0–5 (Part 2A) or 2–5 (Part 2B), and newly diagnosed a-BCL with measurable tumorous disease were included. Pts were treated with GOLCA + Pola-RCHP for six 21-day (D) cycles or until disease progression/unacceptable toxicity/study withdrawal. In dose escalation, GOLCA was dosed at 0.2 and 0.4 mg D1–7. In dose expansion, pts were randomized 1:1 to Pola-RCHP + GOLCA 0.2 or 0.4 mg. Primary endpoint: safety; efficacy was a secondary endpoint. Results: At data cutoff, 57 pts were treated with GOLCA + Pola-RCHP (0.2 mg, n=28; 0.4 mg, n=29). Median age was 63 y. Most pts had HR disease (86%) and DLBCL not otherwise specified histology (84%). For known cell of origin (COO), 47% were germinal center B cell (GCB) and 39% non-GCB by Hans algorithm. Forty-seven pts (83%) completed Tx and 52 (91%) entered the follow-up (f/u) period. Grade 3/4 Tx-emergent adverse events occurred in 95% of pts, most frequently neutropenia (86%; an on-target side effect of GOLCA) and anemia (39%). Median relative dose intensity for GOLCA and Pola-RCHP components was >95%. At 15.5 mo median f/u, end of Tx (EOT) complete metabolic response (CMR) rate was 69% at 0.2 mg, 82% at 0.4 mg, and similar across COO subtypes. EOT CMR was consistent in HR pts (65% at 0.2 mg, 83% at 0.4 mg). The 12-mo DOR and PFS rates were 92% and 88% at 0.2 mg, and 96% and 96% at 0.4 mg. In pts with both pre-Tx and EOT ctDNA analysis, 65% and 83% at 0.2 and 0.4 mg achieved MRD negativity (PhasED-Seq) at EOT. Conclusions: GOLCA + Pola-RCHP demonstrated a predictable and manageable safety profile, and addition of GOLCA did not compromise median dose intensity of Pola-RCHP. GOLCA 0.4 mg + Pola-RCHP resulted in a high rate of durable CMRs, high rate of MRD negativity, and a promising 12-mo PFS rate. These data continue to show that GOLCA + SOC regimens R-CHOP and Pola-RCHP has potential to improve outcomes in 1L HR a-BCL. Clinical trial information: NCT04884035 .

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: 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.