A Phase 1a/1b Dose Escalation/Expansion Study of the Anti-PD-1 Monoclonal Antibody Nofazinlimab in Chinese Patients with Solid Tumors or Lymphoma.

Background: Immune checkpoint blockade with anti-programmed cell death 1 (PD-1) antibodies has demonstrated efficacy in multiple tumor types. Nofazinlimab is a humanized rat antibody targeting PD-1. A first-in-human study of nofazinlimab conducted in Australia found no dose-limiting toxicities (DLTs) and the maximum tolerated dose (MTD) was not reached in the range of 1-10 mg/kg.

Objective: We evaluated nofazinlimab for multiple advanced malignancies in Chinese patients.

Patients and methods: This was a phase 1a/1b, open-label, multicenter, dose-escalation/expansion trial. In phase 1a, patients received an abbreviated dose escalation of nofazinlimab at 60 mg and 200 mg every 3 weeks (Q3W) to determine DLTs and the recommended phase 2 dose (RP2D). In phase 1b, patients received the RP2D (monotherapy/combination) in six arms by tumor type; DLTs were evaluated for nofazinlimab plus lenvatinib in the unresectable hepatocellular carcinoma (uHCC) arm. Safety (continuously monitored in patients who received nofazinlimab) and efficacy (patients with measurable baseline disease) were assessed.

Results: Overall, 107 patients were eligible and received nofazinlimab. In phase 1a, no DLTs were observed; the RP2D was 200mg Q3W. In phase 1b, no DLTs were observed with nofazinlimab plus lenvatinib. The safety profile was consistent with that observed in the first-in-human study (NCT03475251). In phase 1b, 21/88 (23.9%) patients achieved confirmed objective responses, 26 (29.5%) had stable disease, and 9/20 (45.0%) patients with uHCC achieved confirmed objective responses to nofazinlimab plus lenvatinib.

Conclusions: Nofazinlimab was well tolerated in Chinese patients. Preliminary efficacy was encouraging, particularly for nofazinlimab plus lenvatinib in uHCC, which is being studied in an ongoing phase 3 trial.

Clinical trial registration: NCT03809767; registered 18 January 2019.