A phase 1 trial of JS001, a monoclonal antibody targeting programmed death-1 (PD-1) in patients with advanced or recurrent malignancies.

Abstract

e14581 Background: JS001, a humanized IgG4 anti-PD-1 antibody, showed potent anti-cancer activity in preclinical models. Notably, in vivo study suggests it promotes the proliferation of CD62L-CD45RA- effector memory cell effectively. A phase 1 dose escalation study was conducted to assess its safety, tolerability, pharmacokinetic (PK) profile and preliminary efficacy. Methods: This trial used a 3+3 design across 3 dose levels: 1, 3, 10 mg/kg/dose. At each level, two schedules were assessed: single dose and repeated doses every 2 weeks (up to 6 doses). JS-001 was administered as a 60-minute i.v. infusion. A dose limiting toxicity (DLT) was defined as a Grade≥3 drug-related adverse event (AE) occurring within 28 days of last dosing. Results: At the time of analysis, among 19 patients (pts) enrolled (single dose: 9 pts; multiple doses: 10 pts), no DLT was reported. Most treatment-related AEs were grade 1-2, including fever, diarrhea, rash, influenza-like symptoms, fatigue, mucositis, elevated transaminase and decreased lymphocyte count. One patient experienced grade 3 pneumonia. Although the cause of pneumonia is difficult to determine, and further assessment is ongoing, it resolved after prompt management. No treatment-related death occurred. The preliminary PK profile supports a biweekly schedule, and results in detail are under analyzing. 15 pts with evaluable lesions received response evaluation. Best responses were 1 CR (Hodgkin lymphoma, HL), 5 PR (HL: 3; soft tissue sarcoma, STS: 1; diffuse large B-cell lymphoma: 1) and 5 SD (non-small cell lung cancer: 3; head and neck cancer: 2), yielding a disease control rate of 11/15. Remarkably, a patient with STS achieved dramatic tumor shrinkage after a single injection of JS001. Biomarker analysis is in progress. Conclusions: JS001 is well tolerated and the preliminary efficacy results are promising. Updated data on the expansion cohorts at 3mg/kg and 10mg/kg will be presented. Clinical trial information: NCT02836834. Clinical trial information: NCT02836834.