Rationale and design of a multicenter, randomized phase II trial of durvalumab with or without multitarget tyrosine kinase inhibitor as maintenance treatment in extensive-stage small-cell lung cancer patients (DURABLE study).

INTRODUCTION: Durvalumab is a check-point inhibitor against programmed death ligand-1 (PD-L1), and anlotinib is a new orally administered multitarget tyrosine kinase inhibitor (TKI). Both agents have been approved in China. Preclinical and clinical trials have suggested that antiangiogenic therapy has the potential to alleviate immunosuppression and showed synergetic effect when combined with ICIs. However, it is unclear that whether this combination is effective when initiated as maintenance treatment in ES-SCLC patients. METHODS: This is a multicenter, randomized, phase II study. A total of 64 eligible patients who do not experience disease progression after four cycles platinum-based chemotherapy combined with durvalumab will be randomized to durvalumab with anlotinib or durvalumab alone until disease progression, withdrawal of consent, or unacceptable toxicity. The primary endpoint is PFS (from randomization); secondary endpoint was OS and PFS (from diagnosis), objective response rate (ORR); disease control rate (DCR) and duration of response (DOR), safety and tolerability assessed by the National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. DISCUSSION: We conduct a phase II study to investigate the safety and efficacy of durvalumab combined with anlotinib as maintenance treatment in ES-SCLC patients.