Treatment, dose and assessment
toxicity, death
Durvalumab 1500 mg will be administered for all patients concurrently with chemotherapy every 3 weeks, starting on Week 0 for four cycles. Non‐PD patients who completed the four cycles of the combination treatment will be randomized 1:1 into Arm 1 or Arm 2. Eligible patients should begin continuous treatment in 3 days after randomization. In Arm 1, durvalumab 1500 mg monotherapy will be continued every 4 weeks. Anlotinib will be orally administered 12 mg once a day, 14 days‐on and 7 days‐off. Anlotinib is available at three dose levels, 12, 10 and 8 mg. Patients in Arm 2 will be treated with durvalumab monotherapy. Dose reduction may take place whenever toxicity is not controlled with optimal supportive care during the study. If a subject subsequently tolerates treatment well at that level in the judgement of the investigator, the dose may be increased to the next dose level. If a subject cannot tolerate treatment after dose reduction to 8 mg, treatment will be discontinued. Efficacy assessment will be performed every 6–8 weeks. After discontinuation of study treatment, patients will continue to be followed for survival via phone calls or email every 3 months to study end. The survival status (including cause of death) and the date of death or last follow‐up date will be collected.