Multicentre randomized phase II trial of olaparib as maintenance therapy in platinum-sensitive advanced endometrial carcinoma: The GINECO-UTOLA study.

Abstract

TPS6109 Background: Advanced endometrial cancer (EC) patients relapse despite treatment with combination chemotherapy and have a short progression-free survival (PFS). Data from the TGCA suggest opportunities to targeting DNA repair in women with EC. Particularly type 4 (High copy number or serous like, with frequent TP53 mutations) and type 2 (microsatellite instability hypermutated) EC can be associated with defects in double strand break DNA repair by homologous recombination (HR) and could potentially be targeted by olaparib. We propose a placebo-controlled, multicenter, two-arm, phase II trial comparing olaparib versus placebo in maintenance therapy after chemotherapy in patients with advanced/metastatic EC. Methods: The primary objective of this trial is to evaluate the efficacy of maintenance olaparib in comparison to placebo after platinum based chemotherapy, defined by PFS according to Recist. Key eligibility criteria include: advanced/metastatic histologically confirmed EC (excepted carcino-sarcoma, small cells& neuroendocrine); prior surgery, adjuvant chemotherapy, radiation and hormonal therapy are permitted; objective or stable response after first-line chemotherapy is mandatory. 147 patients are randomized (2:1) after chemotherapy to receive Olaparib 300mg twice daily or placebo in maintenance after at least 4 cycles of platinum based chemotherapy. Olaparib/placebo is continued until disease progression, unacceptable toxicity, or withdrawal. Stratification is on IHC P53 and MMR status. Primary hypothesis is a 66.7% relative increase in the median PFS rate in the olaparib arm (from 4.5 to 7.5 months), corresponding to a 0.60 Hazard Ratio. Secondary endpoints include PFS according to P53, MMR and NGS HRD status, PFS2, disease specific survival, time to subsequent therapy, overall survival, objective response, disease control rate, patient reported outcomes (assessed via EORTC QLQ-C30 and EORTC QLQ-EN24, EORTC-FA, EQ5D) and safety. Trial is recruiting in France (in February n= 40 randomization). Conclusion: this will be the first study that evaluate the efficacy of olaparib in maintenace after chemotherapy in advanced/metastastic EC, stratified on molecular profil. Clinical trial information: NCT03745950.