Golseek-1: A Phase 3, Double-Blind, Randomized Study Comparing the Efficacy and Safety of Golcadomide Plus R-CHOP Vs R-CHOP in Patients with Previously Untreated, High-Risk, Large B-Cell Lymphoma

Background and Significance

Diffuse large B-cell lymphoma (DLBCL) and other LBCLs account for 35–40% of non‑Hodgkin lymphoma cases in North America, Europe, and East Asia. Rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP), typically administered for 6 cycles, is the standard therapy for DLBCL and is curative in ~60–70% of patients (pts). However, 30–40% of pts have relapsed/refractory (RR) DLBCL following treatment with R-CHOP, with poor clinical outcomes. International Prognostic Index (IPI) scores of 3–5 are used to identify high-risk (HR) pts who are more likely to be RR following treatment. Additionally, pts with IPI scores of 1–2 who also have bulky disease and/or very high lactate dehydrogenase levels (LDH), have been identified as a HR subset with similar outcomes to pts with an IPI score of 3 (Maurer et al. ASH 2023, #4512). First-line therapy represents the greatest opportunity to address the unmet need for these pts. Golcadomide (GOLCA) is a potential first-in-class oral cereblon E3 ligase modulator (CELMoD™) agent purposefully designed for the treatment of lymphoma. GOLCA co‑opts cereblon to induce targeted degradation of the transcription factors Ikaros/Aiolos, inducing deep, rapid, and extensive tumor killing, independent of cell of origin, and enhanced immunostimulatory activity. In the phase 1b study CC-220-DLBCL-001, GOLCA combined with R-CHOP was well tolerated, showing promising activity and combinability with high rates of durable responses irrespective of cell of origin in pts with previously untreated aggressive BCL, including those with HR disease (Hoffmann et al. EHA 2024, S235). Additionally, GOLCA has shown encouraging efficacy and safety profiles in pts with RR DLBCL, both as a monotherapy (Michot et al. ICML 2023, P90) and in combination with rituximab (Chavez et al. ASH 2023, P4496). The efficacy and safety data observed in early-phase studies suggest promising activity and a manageable safety profile. This supports further investigation of the GOLCA + R-CHOP combination in the phase 3 setting. Here, we present the study design of GOLSEEK-1, a multicenter, randomized, double-blind, placebo-controlled phase 3 study (NCT06356129) comparing the efficacy and safety of GOLCA + R-CHOP vs placebo + R-CHOP in pts with previously untreated HR LBCL.

Study Design and Methods

Approximately 850 pts with previously untreated LBCL will be randomized 1:1 to either GOLCA + R-CHOP or placebo + R-CHOP. Pts must have a histologically confirmed diagnosis of LBCL according to WHO 2022 classification, including: DLBCL, not otherwise specified (NOS) including ABC and GCB subtypes; high-grade B-cell lymphoma with MYC and BCL2 rearrangements, or NOS; T-cell/histiocyte-rich LBCL; Epstein‑Barr Virus-Positive DLBCL. Other key inclusion criteria include an IPI score of 1 or 2 considered HR (LDH > 1.3 × upper limit of normal and/or bulky disease, defined as a single lesion of ≥ 7 cm [Maurer et al. ASH 2023, #4512]), or IPI score ≥ 3; and measurable disease as defined by the Lugano classification. Key exclusion criteria include other lymphoma subtypes such as primary mediastinal LBCL; primary cutaneous DLBCL-leg type, grade 3b follicular lymphoma (FL); transformed indolent lymphoma; anaplastic lymphoma kinase (ALK)‑positive LBCL; primary effusion lymphoma; and Burkitt lymphoma, as well as documented or suspected central nervous system involvement. Randomization will be stratified by IPI score (1–2 with risk factors and 3 vs 4–5) and bulky disease (> 7 cm vs ≤ 7 cm). After a screening period of ≤ 4 weeks, pts will receive GOLCA (0.4 mg) or placebo orally once daily for 7 consecutive days in each of 6 cycles in combination with R-CHOP in 21-day cycles. The primary endpoint of this study is progression-free survival (PFS) in untreated HR LBCL, assessed by investigator based on the Lugano Response Criteria. Key secondary endpoints include PFS in untreated non-high-grade BCL, event‑free survival in pts with untreated HR LBCL, independently assessed complete metabolic response rate, undetectable minimal residual disease by PhasED‑Seq (defined as undetectable circulating tumor DNA levels at treatment end), and overall survival. Patient follow-up will occur for up to approximately 67 months after beginning treatment. This study is recruiting at 293 sites in 37 countries, across the United States, Europe, Latin America, and East Asia.