Epcoritamab monotherapy in patients with relapsed or refractory follicular lymphoma (EPCORE NHL-1): a phase 2 cohort of a single-arm, multicentre study

Background: A standard of care and optimal duration of therapy have not been established for patients with multiply relapsed or refractory follicular lymphoma. The aim of this study was to evaluate epcoritamab, a novel CD3 × CD20 bispecific antibody, in the third-line and later setting of follicular lymphoma. Methods: EPCORE NHL-1 is a multicohort, single-arm, phase 1–2 trial conducted at 88 sites across 15 countries. Here, we report the primary analysis of patients with relapsed or refractory follicular lymphoma in the phase 2 part of the trial, which included the pivotal (dose expansion) cohort and the cycle 1 optimisation cohort. Eligible patients were aged 18 years or older, had relapsed or refractory CD20⁺ follicular lymphoma (grade 1–3A), an Eastern Cooperative Oncology Group performance status of up to 2, and had received at least two previous lines of therapy (including an anti-CD20 monoclonal antibody and an alkylating agent or lenalidomide). Patients were treated with subcutaneous epcoritamab 48 mg in 28-day cycles: weekly in cycles 1–3, biweekly in cycles 4–9, and every 4 weeks until disease progression or unacceptable toxicity. To mitigate the risk and severity of cytokine release syndrome, in the pivotal cohort, cycle 1 consisted of a step-up dosing regimen of a 0·16-mg priming dose on day 1 and a 0·80-mg intermediate dose on day 8, followed by subsequent 48-mg full doses and prophylactic prednisolone 100 mg; in the cycle 1 optimisation cohort, a second intermediate dose of 3 mg on day 15, adequate hydration, and prophylactic dexamethasone 15 mg were evaluated during cycle 1 to further reduce risk and severity of cytokine release syndrome. Primary endpoints were independently reviewed overall response rate for the pivotal cohort and the proportion of patients with grade 2 or worse and any-grade cytokine release syndrome for the cycle 1 optimisation cohort. Analyses were done in all enrolled patients who had received at least one dose of epcoritamab. This study is registered with ClinicalTrials.gov, NCT03625037, and is ongoing. Findings: Between June 19, 2020, and April 21, 2023, 128 patients (median age 65 years [IQR 55–72]; 49 [38%] female and 79 [62%] male) were enrolled and treated in the pivotal cohort (median follow-up 17·4 months [IQR 9·1–20·9]). The overall response rate was 82·0% (105 of 128 patients; 95% CI 74·3–88·3), with a complete response rate of 62·5% (80 of 128; 95% CI 53·5–70·9). The most common grade 3–4 treatment-emergent adverse event was neutropenia in 32 (25%) of 128 patients. Grade 1–2 cytokine release syndrome was reported in 83 (65%) of 128 patients; grade 3 cytokine release syndrome was reported in two (2%). Immune effector cell-associated neurotoxicity syndrome was reported in eight (6%) of 128 patients (five [4%] grade 1; three [2%] grade 2). Between Oct 25, 2022, and Jan 8, 2024, 86 patients (median age 64 years [55–71]; 37 [43%] female and 49 [57%] male) were enrolled and treated in the cycle 1 optimisation cohort. The incidence of cytokine release syndrome was 49% (42 of 86 patients; eight [9%] grade 2; none of grade 3 or worse), with no reported immune effector cell-associated neurotoxicity syndrome. Interpretation: Epcoritamab monotherapy showed clinically meaningful activity in patients with multiply relapsed or refractory follicular lymphoma, and had a manageable safety profile. Funding: Genmab and AbbVie.