Does Niraparib Treatment Increase Survival for Those with Newly Diagnosed Ovarian Cancer?

BACKGROUND AND PURPOSE:

• Up to 85% of women with advanced ovarian cancer will have a recurrence
• Niraparib is a PARP inhibitor used for maintenance therapy after platinum-based chemotherapy
• Efficacy of niraparib for newly diagnosed advanced ovarian cancer is unknown
• González-Martín et al. (NEJM, 2019) studied the efficacy and safety of niraparib therapy after platinum-based chemotherapy for patients with newly diagnosed advanced ovarian cancer at high risk for relapse

METHODS:

• Randomized, double-blind, phase 3 trial (RCT)
• Participants
  • Newly diagnosed advanced ovarian cancer
• Patients random assigned (2:1) into either
  • Intervention: Niraparib once daily after a response to platinum-based chemotherapy
  • Control: Placebo once daily after a response to platinum-based chemotherapy
• Primary outcome: Progression-free survival among
  • Patients who had tumors with homologous-recombination deficiency (pathogenic variants in BRCA genes or structural chromosomal alterations or other genomic changes that would indicate abnormal repair mechanisms)
  • Overall population
• Secondary outcome: Overall survival

RESULTS:

• 733 patients randomized | 50.9% had tumors with homologous-recombination deficiency
• Patients that had tumors with homologous-recombination deficiency: Median progression-free survival was significantly longer in the niraparib group (P<0.001)
  • Niraparib: 21.9 months
  • Placebo: 10.4 months
  • Hazard ratio (HR) for disease progression or death: 0.43 (95% CI, 0.31 to 0.59)
• Overall population: Progression-free survival was also significantly longer in the niraparib group (P<0.001)
  • Niraparib:13.8 months
  • Placebo: 8.2 months
  • HR for disease progression or death: 0.62 (95% CI, 0.50 to 0.76)
• Overall survival at 24-month interim analysis
  • Niraparib: 84% 
  • Placebo: 77%
  • HR 0.70 (95% CI, 0.44 to 1.11)
• The most common significant adverse events (≥ grade 3)
  • Anemia: 31%
  • Thrombocytopenia: 28.7%
  • Neutropenia: 12.8%
  • No deaths reported

CONCLUSION:

• Following response to platinum-based chemotherapy, niraparib treatment resulted in significantly longer progression-free survival vs placebo in patients with newly diagnosed ovarian cancer
• The presence or absence of homologous-recombination deficiency did no impact these results
• The authors also state that

…overall survival may also be improved, but the data are not sufficiently mature to assess this end point with precision

Learn More – Primary Sources:

Niraparib in Patients with Newly Diagnosed Advanced Ovarian Cancer