Phase 1b Multicenter Study of SG001, a Humanized Anti-PD-1 Antibody, in Patients with Advanced Solid Tumors

SG001 is a humanized, IgG4 monoclonal antibody against human PD-1. This phase 1b study aimed to evaluate efficacy and safety of SG001 in advanced solid tumors.

Patients with previously treated solid tumors that are PD-L1-positive, and/or dMMR/MSI-H, and/or Epstein-Barr virus positive were enrolled in Cohort A, while patients with PD-L1-unselected malignant mesothelioma and PD-L1-unselected non-small cell lung cancer (NSCLC) were enrolled in Cohorts C and E, respectively. All patients in Cohorts A, C, and E received SG001 at a dose of 240mg every two weeks for 2 years or until disease progression, intolerable toxicities, or withdrawal of consent. The primary endpoint was the investigator-assessed overall response rate (ORR).

A total of 87 patients were enrolled: 33 in Cohort A, 24 in Cohort C, and 30 in Cohort E. Investigator-assessed ORR was 39.4% in Cohort A, 12.5% in Cohort C, and 16.7% in Cohort E; corresponding median PFS values were 9.6, 4.1, and 4.0 months. The most common treatment-related adverse events (TRAEs) were increased alanine aminotransferase (13.8%), proteinuria (12.6%), rash (12.6%), and increased aspartate aminotransferase (10.3%). No TRAEs leading to death were reported.

SG001 demonstrated promising activity in patients with pretreated advanced solid tumors, especially those with PD-L1-positive NSCLC. The safety profile was well tolerated.

ClinicalTrials.gov identifier: NCT03852823.