Rueda‐Domínguez, Antonio

Introduction Up to 40% of pts with diffuse large B-cell lymphoma (DLBCL) relapse after first-line chemo-immunotherapy with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). CELMoD agents such as GOLCA potently degrade target proteins Ikaros/Aiolos, resulting in antiproliferative, apoptotic, and immunomodulatory activity. GOLCA preferentially distributes to tissues and lymphoid organs. In a phase 1 study, GOLCA demonstrated a manageable safety profile with promising clinical activity as monotherapy in relapsed/refractory non-Hodgkin lymphoma (Michot et al. Blood 2021). CC-220-DLBCL-001 (NCT04884035) is an ongoing open-label, multicenter, dose escalation and expansion trial to assess safety and preliminary efficacy of CELMoD agents + R-CHOP for untreated a-BCL. GOLCA demonstrated a manageable safety profile in the dose escalation phase (Munoz et al. ICML 2023 abstract 438); we report combined results from the GOLCA dose escalation and expansion phases. Methods Eligible pts were ≥ 18 years, had untreated a-BCL with measurable disease (Lugano 2014), ECOG performance status ≤ 2 and International Prognostic Index (IPI) score 0-5 (2-5 in dose expansion). Pts were treated with R-CHOP plus GOLCA in 21-day (D) cycles (C) for up to 6C, or until disease progression/unacceptable toxicity/study withdrawal/physician decision. During dose escalation, pts received GOLCA at dose levels (DL): 0.2 mg D1-7 (DL-1), 0.4 mg D1-7 (DL1), and 0.4 mg D1-10 (DL2). DL2 met the dose-limiting toxicity threshold and was not continued in the expansion phase. During dose expansion, pts were randomized 1:1 to R-CHOP plus GOLCA at DL-1 or DL1. The primary endpoint for the expansion phase was safety of GOLCA at the recommended phase 2 dose (DL1) (based on adverse events [AEs]); secondary endpoints included overall response rate (ORR) and complete metabolic response (CMR) rate (assessed at end of treatment [EoT] by PET-CT [Lugano 2014]). Circulating tumor DNA (ctDNA) was measured at C1D1, C2D1, C3D1, and EoT using the PhasED-Seq assay. Results Across escalation and expansion, 78 pts were treated (DL-1, n = 35; DL1, n = 37; DL2, n = 6). Median age was 63.0 years, 56.4% were male, most had high-intermediate/high IPI (3-5) score at diagnosis (64.1%), Ann Arbor stage III-IV disease (83.3%), and germinal center B cell as cell of origin (51.3%); 83.3% pts had DLBCL histology. At data extraction (May 25, 2023), across escalation and expansion, 38 pts had treatment ongoing, 31 completed treatment, and 35 continued to follow-up. A total of 3 pts discontinued due to AEs, 1 each at DL-1, DL1, and DL2. In the safety population (n = 78), median GOLCA relative dose intensity (RDI) was 99.4%; 82.1% of pts received RDI ≥ 85%. RDI for CHOP components was > 90%. A total of 73 (93.6%) pts had ≥ 1 treatment-emergent AE (TEAE); 70 (89.7%) pts had ≥ 1 TEAE considered related to GOLCA; 65 (83.3%) pts had ≥ 1 grade 3/4 TEAE, 62 (79.5%) pts had ≥ 1 grade 3/4 TEAE considered related to GOLCA. The most frequently occurring grade 3/4 TEAEs were neutropenia (76.9%) and thrombocytopenia (32.1%) ( Table). A total of 30 (38.5%) pts had serious TEAEs, most frequently febrile neutropenia (preferred term: 11 pts, 14.1%); 12 (15.4%) pts had serious TEAEs of infection or infestation (system organ class); 6 pts (7.7%) had venous thromboembolisms considered related to GOLCA (4 deep vein thrombosis, 1 superficial thrombosis, 1 pulmonary embolism). Treatment-related AEs leading to GOLCA dose reduction or discontinuation occurred in 11 (14.1%) pts and 6 (7.7%) pts, respectively. After a median follow-up time of 4.1 months (range 0.3-12.3) and among all treated pts with EoT response available, 21/25 had CMR; together, 14/14 pts who received GOLCA 0.4 mg (DL1 and DL2) achieved CMR at EoT ( Figure). Among efficacy-evaluable pts (n = 56), ORR was 91.1% (95% CI 80.4-97.0). Pts treated with GOLCA at DL-1 and DL1 who were ctDNA high-risk (≥ 2.5 log hGE/mL) responded to study treatment (CMR-PMR) and had early decreases in ctDNA (Kaplan et al. ASH 2023). Conclusions GOLCA demonstrated a manageable safety profile, showed good combinability with R-CHOP, and did not compromise delivery of curative treatment. Efficacy results and substantial ctDNA decrease indicate robust clinical activity in frontline DLBCL, with a high CMR rate at EoT, particularly among patients treated at DL1. Study support Bristol Myers Squibb.