Phase 2 Multi-center Study of Anti-PD-1 During Lymphopenic State After HDT/ASCT for Multiple Myeloma

Multiple myeloma (MM) is a common incurable blood cancer causing debilitating symptoms-bone pain, kidney failure, low blood counts and infection. Chemotherapy outcomes are disappointing due to short-term response and long-term toxicities. 1. Studies showed these patients have weak immune against MM due to the immune checkpoint mediated by the PD1/PD-L1 interaction between immune cells and MM. Anti-PD-1 antibody (anti-PD1) disrupts this interaction, thus unleashing immune cell function and leading to killing of MM cells. 2. Studies further showed enhancement of this "unleash" after autologous transplant and better MM control by anti-PD1 when used after transplant. 3. Anti-PD1 has been extensively studied in patients with other cancers. It is very safe and effective and has been FDA-approved. Complications are of mild degree and easy to manage successfully in out-patient setting. Severe complications are rare. Thus, investigators proposed an efficacy study of anti-PD1 treatment after transplant to improve MM treatment outcomes. This was a collaborative study with Medical College of Wisconsin (headquarter of Center for International blood and Marrow Transplant Research). Investigators hypothesized that anti-PD1 treatment would increase the MM response and the MM control duration when added to the standard MM treatment after transplant. Anti-PD1 was given at the dose and interval, which had been studied previously (200 mg intravenous injection every 3 weeks) between 2 weeks until 6 months after transplant. Subjects were monitored closely during and after anti-PD1 therapy until at least 1 year post transplant. Late complications were followed for 3 years.