Safety, tolerability, and pharmacokinetics of an anti-LAG-3 antibody SHR-1802 in patients with advanced solid tumors: a phase I dose-escalation and dose-expansion study.

Abstract

Lymphocyte-activation gene 3 (LAG-3), a checkpoint molecule contributing to immune suppressive microenvironment, is regarded as a promising target in cancer treatment. SHR-1802 is a novel anti-LAG-3 monoclonal antibody. To evaluate the safety, tolerability, pharmacokinetics, and antitumor activity of SHR-1802. A phase I dose-escalation and expansion trial of SHR-1802 in patients with advanced solid tumors. Patients with confirmed advanced solid tumors who failed previous standard-of-care or for whom no effective therapy was available were enrolled to receive SHR-1802 once every 21-day cycle. Dose escalation was performed in an accelerated titration design followed by a 3 + 3 scheme at escalating doses from 0.3 to 10 mg/kg. On the basis of results from dose-escalation phase, one or two dose levels were expanded to establish the recommended phase II dose (RP2D). The primary end points were dose-limiting toxicity (DLT) and RP2D. Between 01 July 2020, and 07 September 2021, 28 patients were enrolled. No DLTs were observed, and all doses investigated were well tolerated. Treatment-related adverse events occurred in 20 patients (71.4%), all grade 1 or 2, with the most common ones being anemia (14.3%), asthenia (14.3%), electrocardiogram QT prolonged (14.3%), followed by increased blood fibrinogen (10.7%), infusion-related reaction (10.7%), and hypoalbuminemia (10.7%). No adverse event-related discontinuation occurred. Three patients died from adverse events, but none of the deaths were deemed related to study treatment. SHR-1802 exposure enhanced with the increasing doses in a greater than dose-proportional manner over the investigated dose range. The disease control rate was 32.0% (95% CI 14.9%-53.5%). The median progression-free survival was 2.0 months (95% CI 1.2-6.1). SHR-1802 demonstrated a tolerable safety profile and preliminary antitumor activity in patients with advanced solid tumors. Further studies with larger sample size and in combination forms are warranted for future clinical application. NCT04414150.