A Phase II Trial to Evaluate the Efficacy of Bortezomib and Liposomal Doxorubicin in Patients With BRCA Wild-type Platinum-resistant Recurrent Ovarian Cancer (KGOG 3044/EBLIN)

Background/Aim: The majority of targeted therapies are focused on BRCA mutations, homologous recombination repair deficiency, and BRCA wild-type platinum-sensitive recurrent ovarian cancer. There is a growing need for platinum-resistant patients without BRCA mutations. Herein, we conducted a phase II multicenter study evaluated the efficacy and safety of bortezomib plus pegylated liposomal doxorubicin (PLD) in patients with BRCA wild-type platinum-resistant recurrent ovarian cancer (NCT03509246). Patients and Methods: Ovarian cancer patients with wild-type BRCA who experienced platinum-resistant recurrence after three or less prior treatment cycles from three Institutions were included. All patients received bortezomib, 1.3 mg/m(2) subcutaneously (days 1, 4, 8, and 11), and PLD, 40 mg/m(2) intravenously (day 4), every 4 weeks. The primary endpoint was best objective response rate (ORR), and secondary endpoints included disease control rate, progression-free survival (PFS), overall survival, and safety. Targeted sequencing was performed to evaluate biomarkers and their potential association with response to treatment. Results: The trial was terminated after 23 patients were recruited because of slow accrual. The median follow-up was 29.5 months. The overall ORR was 8.7% (2/23); partial response was observed in two patients. The median duration of response was 10.5 months, and median PFS was 2.9 months. Treatment-related adverse events (TRAEs) of grade 3/4 were reported in 43.5% of patients. One patient who exhibited TRAEs discontinued treatment. However, grade 4/5 TRAEs were not observed. Mutations in TP53 and CDK12 were detected in 67% (14/21) and 24% (12/21) of patients, respectively. Two patients with partial response harbored mutations in genes related to homologous recombination repair deficiency, including BRCA2, ATM, and CDK12. Conclusion: The combination of bortezomib and PLD was well tolerated; however, antitumor activity was not sufficient to warrant further investigation in ovarian cancer.