Last year at the European Society for Medical Oncology (ESMO) annual meeting, AstraZeneca and Merck showed Lynparza could beat two top rivals at fending off prostate cancer progression. This year, they’re showing it can help patients live longer, too.
In results unveiled Sunday at the ESMO virtual congress, Lynparza cut the risk of death by 31% over Johnson & Johnson’s Zytiga or Pfizer and Astellas’ Xtandi in patients with metastatic, castration-resistant prostate cancer and one of three genetic mutations.
Men with BRCA1, BRCA2 or ATM-mutated cancers lived 19.1 months versus 14.7 months for those on Zytiga or Xtandi—and that was despite two-thirds of patients in the control arm crossing over to receive Lynparza after their disease worsened.
“I think this really underscores that we’ve got an important new treatment paradigm in prostate cancer,” said Dave Fredrickson, executive vice president and global head of AstraZeneca’s oncology business unit.
The data follow just a year after Lynparza showed it could cut the risk of disease progression or death in the same population by 66%. Execs from both companies hailed the results as game-changing, noting the performance marked the advent of precision medicine in prostate cancer.
And this past May, U.S. regulators used those data to greenlight Lynparza in men with homologous recombination repair mutations, a group that includes BRCA1, BRCA2, ATM and 12 other genes.
But while progression-free survival “is a meaningful endpoint to patients … the gold standard, of course, is always being able to deliver improvements in overall survival,” Fredrickson said.
And it’s not just the gold standard for doctors and patients; it’s also the gold standard for payers. “We now have some really critical components for compelling value propositions for payers,” Fredrickson noted, pointing to biomarker data and overall survival data. “Those two things together mean we can define the patient population who benefits, and equally define those patients we shouldn’t be treating.”
The new data also give the AZ-Merck team a leg up on rival drugmaker Clovis Oncology, which nabbed an OK for its PARP inhibitor, Rubraca, in BRCA-mutated metastatic, castration-resistant prostate cancer just days before Lynparza did.
Lynparza’s “overall survival advantage was not anticipated, and we believe should prove to be a significant commercial advantage,” SVB Leerink analyst Andrew Berens wrote in an April note to clients.
Elsewhere at ESMO, AstraZeneca and Merck trotted out five-year Lynparza data in BRCA-mutated ovarian cancer, showing the drug could keep cancer at bay for more than 4.5 years in women who responded partially or completely to chemo.