Abstract CT041: The efficacy and safety of Geptanolimab (GB226) in patients with relapsed/refractory peripheral T cell lymphoma (PTCL): A multicenter, open-label, single-arm, phase 2 trial

Background: There was an unmet medical need for treatment in patients with relapsed/refractory (R/R) peripheral T cell lymphoma (PTCL). This multicenter, open-label, single-arm, phase 2 trial aimed to evaluate the efficacy and safety of Geptanolimab (GB226), an anti-programmed cell death 1 (PD-1) antibody, in patients with R/R PTCL(NCT03502629). Methods: The study was initiated in July 2018 and patients with R/R PTCL were recruited from 32 sites in China. Patients were treated with Geptanolimab (intravenous infusion, 3 mg/kg) once every 2 weeks until disease progression or intolerable toxicity. The primary endpoint was objective response rate (ORR). The secondary endpoints included duration of response (DOR), time to response (TTR), disease control rate (DCR), progression-free survival (PFS), overall survival (OS), safety, and immunogenicity. Treatment response was assessed according to Lugano 2014 criteria by the independent review committee. Patients were followed up every 6 weeks for the first year, and every 12 weeks thereafter. Results: By Aug 15, 2019, a total of 102 patients were recruited and treated with Geptanolimab. As of Nov 1, 2019, the median follow-up was 3.98 months (0.30,15.63). The ORR was 36.3% (37/102; 95%CI: 26.98%-46.39%), including of 11 (10.8%) patients achieved CR and 26 (25.5%) patients achieved PR. DCR was 55.9% (57/102; 95%CI: 45.71%-65.71%). The median DOR, TTR, and PFS were 6.83 months (95%CI: 5.13-not reached [NR]), 4.04 months (95% CI: 1.48-8.52), and 2.69 months (95%CI: 1.74-4.21), respectively. The median OS has not been reached. Subgroup analyses showed that the efficacy was consistent across different age, gender, clinical stage, and previous treatment lines. Patients could benefit from Geptanolimab after failure of Chidamide (an oral histone deacetylase [HDAC] inhibitor) treatment with an ORR of 33.3% (8/24). The ORR of patients with anaplastic lymphoma kinase-negative anaplastic large cell lymphoma (ALCL ALK-), ALCL ALK+, extranodal NK-/T-cell lymphoma, nasal type (ENKTL), PTCL-not otherwise specified (PTCL-NOS), and other types were 58.3% (7/12), 42.9% (3/7), 40.9% (9/22), 28.2% (11/39), and 31.8% (7/22) respectively. Treatment-related AEs (TRAEs) occurred in 80.4% of patients, with common TRAEs (incidence ≥10%) of white blood cell count reduction (18.6%), fever (14.7%) and anemia (13.7%). The incidence of grade ≥3 TRAEs and treatment-related serious AEs was 23.5% and 15.7%, respectively. Immune-related AEs (irAEs) oc