TP034/#1534 Randomized phase III trial on niraparib-TSR-042 (Dostarlimab) versus physician’s choice chemotherapy in recurrent ovarian, fallopian tube, primary peritoneal cancer platinum resistant patients: nitche trial(MITO 33)

Abstract

Objectives Platinum resistant ovarian cancer (OC) patients have a poor prognosis, and few treatment options are available. Preclinical and clinical data demonstrated that the combination PARP inhibitors with immune checkpoint inhibitors could have a synergistic antitumor activity in this setting of patients. MITO 33 trial will assess the hypothesis that the combination niraparib/dostarlimab therapy is effective in increasing overall survival (OS), progression free survival (PFS) and time to first subsequent therapy with respect to chemotherapy alone. Methods Recurrent platinum resistant OC will be randomized 1:1 to receive: ‐Arm A: pegylated liposomal doxorubicin 40 mg/mq d1q28, weekly paclitaxel 80 mg/mq d1,8,15q28, gemcitabine 1000 mg/mq d1,8,15q28 or topotecan 1.25 mg/mq d1‐5q21; ‐Arm B: dostarlimab 500 mg every 3 weeks for 4 cycles, then 1000 mg every 6 weeks + niraparib 300 mg or 200 mg daily. Patients will be stratified according to homologous recombination deficiency status (positive vs negative) evaluated with Foundation One CDx LOH test, PD‐L1 status, previous immunotherapy, previous PARPi treatment and Bevacizumab therapy. Endpoints Primary Endpoint: OS Secondary Endpoints: PFS; Time to First Subsequent Therapy and Objective Response Rate; Safety and Tolerability of Dostarlimab plus Niraparib Exploratory Objective: relationship between PD‐L1 expression and the efficacy of niraparib/dostarlimab treatment; relationship between lymphoid or myeloid‐derived suppression cells or T‐regulatory cells (T‐regs) and response to niraparib/dostarlimab treatmen Results Trial in progress: there are no available results at the time of submission Conclusions Trial in progress: there are no available conclusions at the time of submission.