Efficacy and safety of sintilimab plus docetaxel in patients with previously treated advanced non-small cell lung cancer: a prospective, single-arm, phase II study in China

Purpose: Although immune checkpoint inhibitor monotherapy has been used as a second-line treatment in advanced non-small cell lung cancer (NSCLC), the improvement in progression-free survival (PFS) remains unsatisfactory. We investigated the feasibility of sintilimab plus chemotherapy as a second-line treatment in advanced NSCLC.

Methods: This was a phase II, single-arm, prospective study in advanced NSCLC patients who had failed standard platinum-based chemotherapy (ChiCTR1900027634, Registered 22 November 2019). Eligible patients received docetaxel 75 mg/m² (day 1) plus sintilimab 200 mg (day 3) Q3W. Those did not progress after 4-6 cycles received sintilimab 200 mg Q3W as maintenance treatment. The primary endpoint was PFS.

Results: Forty patients were enrolled between October 2019 and October 2020. With a median follow-up of 12.2 months, the median PFS was 5.8 months, and the PFS rates at 6 and 12 months were 48% and 30%, respectively. The median overall survival (OS) was 12.6 months, with a 12-month OS rate of 62.0%. The overall response rate was 32.4%, and the disease control rate was 89.2%. The incidence of all and ≥ grade 3 treatment-related adverse events (TRAEs) were 65% (26/40) and 17.5% (7/40), respectively. No TRAEs-related permanent treatment discontinuation or death occurred. bTMB reduction at 6 weeks was associated with a longer PFS (NR vs 3.0 months, P < 0.0001).

Conclusion: This prospective phase II study in China suggested that sintilimab plus docetaxel might improve PFS and tumor response with good tolerability for Chinese patients with previously treated advanced NSCLC. bTMB reduction at 6 weeks could serve as a potential predictive biomarker for this regimen.