Research Article|Articles in Press, 100478

Efficacy and Safety of Anti-PD-L1 Monoclonal Antibody Socazolimab with Carboplatin and Etoposide for Extensive-Stage Small Cell Lung Cancer: Results from the Phase Ib Clinical Trial

Open AccessPublished:February 28, 2023DOI:
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      The study (, NCT04346914) is an open label, single-arm phase Ib clinical trial investigating the safety, tolerability, and efficacy of the recombinant human anti-programmed death-ligand 1 (PD-L1) monoclonal antibody Socazolimab in combination with carboplatin and etoposide in the first-line treatment of extensive-stage small cell lung cancer (ES-SCLC). Good safety and efficacy were demonstrated in previous phase I clinical trials of other cancers like cervix cancer.

      Experimental Design

      Patients received Socazolimab (5mg/kg) every three weeks until disease progression or physician decision. Carboplatin(AUC 5) was also administered every three weeks, and etoposide (100mg/m2) on days 1, 2, and 3 of the treatment cycle. The primary purpose of the study was safety mesured by CTCAE. Secondary purposes included the objective response rate (ORR), progression-free survival (PFS), duration of response (DOR), and overall survival (OS).


      From 15th April 2020 (enrollment date) to 30th December 2021 (data cutoff), 20 patients with ES-SCLC were administered with Socazolimab, carboplatin and etoposide. ORR was 70.0% (95% CI: 45.72%, 88.11%). Median PFS was 5.65 months (95% CI: 4.14, 6.54), and the median DOR was 4.29 months (95% CI: 2.76, 5.85). Median OS was 14.88 months (95% CI: 10.09, NE). The highest incidence of TRAEs included anemia (100%), decreased neutrophil count (95%), decreased platelet count (95%) and decreased white blood cell count (95%) which occurred during combination therapy. The most common grade 3 or 4 TRAEs were neutropenia (90%), decreased white blood cell count (65%), decreased platelet count (50%) and anemia (30%) which were also common adverse reaction of chemotherapy. No adverse events leading to death had occurred.


      Results revealed that the combination therapy of Socazolimab, carboplatin and etoposide had preliminarily confirmed the safety of Socazolimab in the first-line treatment of SCLC combined with EC chemotherapy. Currently, a phase III, randomized, placebo-controlled trial (, NCT04878016) is being conducted with 498 patients.