Zai Lab announces JAMA Oncology published data from Phase 3 study on ZEJULA

Zai Lab announced that JAMA Oncology published data from the pivotal Phase 3 PRIME study evaluating ZEJULA as a first-line maintenance therapy in Chinese patients with newly diagnosed advanced ovarian cancer. These data demonstrate that maintenance treatment with ZEJULA significantly prolongs progression-free survival versus placebo and reduces the risk of disease progression or death by 55%. The PRIME study is a Phase 3, randomized, double-blind, placebo-controlled clinical trial conducted at 29 hospitals in mainland China. The primary endpoint was blinded independent central review (BICR)-assessed PFS in the intention-to-treat population. The JAMA Oncology PRIME publication includes the following key efficacy and safety findings: ZEJULA significantly extended PFS versus placebo and reduced the risk of disease progression or death by 55%, regardless of postoperative residual disease or biomarker status. Median PFS with ZEJULA versus placebo in the ITT population was 24.8 versus 8.3 months. At the time of data cut-off, overall survival data were not yet mature in the ITT population. Utilization of an ISD demonstrated a tolerable safety profile in the maintenance setting. Grade greater than or equal to3 treatment-emergent adverse events and serious adverse events were reported in 54.5% versus 17.8% and 18.8% vs 8.5% in ZEJULA-treated and placebo-treated patient respectively. Similar proportions of ZEJULA-treated and placebo-treated patients discontinued therapy due to TEAEs. Additional sub-analyses consistently demonstrated that ZEJULA improved PFS versus placebo in a broad range of patients: PFS not reached versus 10.8 months in patients with the gBRCA mutation; 19.3 versus 8.3 months in patients without the gBRCA mutation; 24.8 versus 8.3 months in patients with optimal debulking; 16.5 versus 8.3 months in patients with suboptimal debulking