Durvalumab in DLBCL After Autologous Transplant

Background and Rationale: Autologous stem cell transplantation (ASCT) is standard of care in the treatment concept of adult patients with multiple myeloma (MM), malignant lymphomas (including diffuse large B-cell lymphomas (DLBCL), mantle cell lymphomas, follicular lymphomas or T-cell lymphomas), acute myeloid leukemia (AML) and relapsing germ cell tumors. The number of patients treated with ASCT is steadily increasing, e.g. by +17% alone in Switzerland in the year 2015, to a total of 464 ASCT per year in Switzerland. The Inselspital (University Hospital) in Berne is the leading hospital in Switzerland for ASCT, with 145 ASCT in the year 2015. Among these 145 transplants, 31 patients had DLBCL. The goal of treatment in DLBCL is definite cure. In DLBCL, the addition of anti-CD20 treatment to standard CHOP (Cyclophosphamid, Doxorubicin, Vincristine, Prednisone) chemotherapy has improved the cure rate after R-CHOP (Rituximab-CHOP) first-line treatment. Nevertheless, the disease is relapsing in roughly 20% of these patients. At relapse, patients are treated with salvage chemotherapy such as the R-DHAP (Rituximab, Dexamethasone, Cisplatin,Cytarabine), or R-ICE (Rituximab,Ifosfamide, Carboplatin, Etoposide) regimens, followed by BEAM (BCNU, Etoposide, Cytarabine, Melphalan) or BeEAM (Bendamustin, Etoposide, Cyclophosphamide, Melphalan) high-dose chemotherapy supported with ASCT. The overall survival rate at the Inselspital Bern and elsewhere at two years for DLBCL patients after ASCT is 60%, and, therefore, improving outcome of such patients remains an unmet clinical need. This is particularly true in high-risk DLBCL patients, such as in DLBCL patients relapsing within 12 months after first-line treatment as well as in DLBCL patients not achieving a (first or second) complete remission (CR) after induction treatment before ASCT. PFS at two years for such high-risk lymphoma patients is 50% at the investigators' institution. Immunotherapy (such as with PD-L1 inhibition) after ASCT is a promising approach to potentially improve results after ASCT. A first study applying PD-1 inhibition with three applications (every 42 days) of Pidilizumab started between days 30 and 90 after ASCT showed a promising progression-free survival rate of 72% in relapsing DLBCL patients at 16 months after the first Pidilizumab application. These data suggest that immunotherapy after ASCT has the potential to a meaningful improvement of survival rates in DLBCL patients after ASCT. Objective: The primary objective of this Trial is to show a progression-free survival of 70% two years after autologous stem cell transplantation (ASCT) in high-risk DLBCL patients receiving PD-L1 inhibition with durvalumab. Study Duration: The 46 patients needed in this study will be included within 24 months. Additional 24 months will be needed until the last study patient reaches PFS at 2 years. Accordingly, the total study duration is expected to be 48 months.