This is a single-arm phase 2 study with fixed does of combined Sintilimab and Chidamide regimen. This regimen is repeated every 21 days. Sintilimab (200mg) is administered intravenously on day 1 of every cycle. Chidamide is used 20mg twice per week continuously. From the beginning of the trial, sindilimab will be used for 96 weeks, until disease progress, intolerable toxicity or patient/investigator discretion. Patients will continue to receive Chidamide treatment until disease progression, unacceptable toxicity, or patient/investigator discretion.
The response will be evaluated every 2 cycles in the first 36 weeks and every 4 cycles from week 36 till the end of treatment. The patients who achieve complete remission (CR), partial remission (PR), and stable disease (SD) will receive further treatment. The patients with progressed disease (PD) will be continue on the treatment and reassess after 4-8 weeks to rule out false progression. On confirmation of PD , patients will be withdrawn from the trial and receive salvage regimens.
