84P SHR-1316 vs placebo in combination with chemotherapy as perioperative treatment in patients with resectable stage II-III NSCLC: A randomized, double-blind, multicenter, phase Ib/III trial

Abstract

SHR-1316 is a humanized IgG4 monoclonal PD-L1 antibody which has shown promising antitumor activity in solid tumors. This phase 1b/3 trial evaluates the efficacy and safety of SHR-1316 plus chemotherapy vs placebo plus chemotherapy as perioperative treatment for resectable NSCLC. Here, we reported the results from the phase 1b study. Eligible patients were resectable stage II and III (IIIA and T3N2M0 IIIB) NSCLCs without EGFR/ALK alterations. Patients received neoadjuvant treatment with 3 cycles of intravenous SHR-1316 (20 mg/kg on day 1), nab-paclitaxel (100 mg/m2 on days 1, 8, and 15), and carboplatin (area under the curve 5, 5 mg/mL per min on day 1), of each 21-day cycle, followed by surgical resection. After that, patients further received 16 cycles of SHR-1316 (20 mg/kg on day 1) adjuvant treatment. The primary endpoint was major pathological response (MPR) per blinded independent pathological review (BIPR), defined as ≤10% viable tumor cells in resection specimen. If MPR was >55% then phase 3 trial will be initiated. From Jul 14, 2020 to May 12, 2021, 37 patients received SHR-1316 plus chemotherapy neoadjuvant treatment and 34 patients underwent surgery. As of data cutoff on Nov 26, 2021, 19 (55.9%, 95% CI 39.5-71.1) of the 34 patients underwent surgery achieved MPR per BIPR and 11 (32.4%, 95% CI 19.1-49.2) patients achieved pathological complete response. Of the 37 patients received neoadjuvant treatment, 26 (70.3%, 95% CI 54.2-82.5) patients had an objective response per RECIST v1.1, including 1 with complete response and 25 with partial response. Treatment-related adverse events (AEs) were reported in 37 (100%) patients. 29 (78.4%) patients had grade ≥3 treatment-related AEs and 9 (24.3%) had treatment-related serious AEs. No treatment-related deaths occurred. Grade ≥3 surgery-related AEs within 30 or 90 days after surgery were both reported in 6 (17.6%) of the 34 patients. SHR-1316 in combination with nab-paclitaxel and carboplatin as neoadjuvant therapy showed a high proportion of MPR in resectable NSCLC, and the safety profile was well tolerated. Based on the phase 1b results, the phase 3 trial was initiated and ongoing.