Fuzuloparib Maintenance Therapy in Patients With Platinum-Sensitive, Recurrent Ovarian Carcinoma (FZOCUS-2): A Multicenter, Randomized, Double-Blind, Placebo-Controlled, Phase III Trial.

PURPOSE

This phase III trial aimed to explore the efficacy and safety of fuzuloparib (formerly fluzoparib) versus placebo as a maintenance treatment after response to second- or later-line platinum-based chemotherapy in patients with high-grade, platinum-sensitive, recurrent ovarian cancer.

PATIENTS AND METHODS

Patients with platinum-sensitive, recurrent ovarian cancer previously treated with at least two platinum-based regimens were assigned (2:1) to receive fuzuloparib (150 mg, twice daily) or matching placebo for 28-day cycles. The primary end points were progression-free survival (PFS) assessed by blinded independent review committee (BIRC) in the overall population and PFS by BIRC in the subpopulation with germline mutation.

RESULTS

Between April 30, 2019, and January 10, 2020, 252 patients were randomly assigned to the fuzuloparib (n = 167) or placebo (n = 85). As of July 1, 2020, the median PFS per BIRC assessment in the overall population was significantly improved with fuzuloparib treatment (hazard ratio [HR], 0.25; 95% CI, 0.17 to 0.36; one-sided < .0001) compared with that with placebo. The HR derived from a prespecified subgroup analysis showed a consistent trend of benefit in patients with germline mutations (HR, 0.14; 95% CI, 0.07 to 0.28) or in those without mutations (HR, 0.46; 95% CI, 0.29 to 0.74). The most common grade ≥ 3 treatment-emergent adverse events reported in the fuzuloparib group were anemia (25.1%), decreased platelet count (16.8%), and decreased neutrophil count (12.6%). Only one patient (0.6%) discontinued fuzuloparib because of treatment-related toxicity (concurrent decreased white blood cell count and neutrophil count).

CONCLUSION

Fuzuloparib as maintenance therapy achieved a statistically significant and clinically meaningful improvement in PFS for patients with platinum-sensitive, recurrent ovarian cancer versus placebo, regardless of germline mutation, and showed a manageable safety profile.