AstraZeneca and Merck's Lynparza pressures Clovis' Rubraca with prostate cancer OK

Prostate cancer is the fourth disease area for AstraZeneca and Merck's Lynparza. (AstraZeneca)

AstraZeneca and Merck & Co.’s Lynparza has officially entered its fourth tumor type. And while it may not be the first drug in its class to break into its latest field, analysts still expect it to rise to the top.

Tuesday, the FDA green-lighted the drug in prostate cancer, clearing the PARP inhibitor for use in patients with previously treated metastatic, castration-resistant patients with mutations in their homologous recombination repair (HRR) genes.

RELATED: ESMO: AZ, Merck's Lynparza brings precision medicine to prostate cancer with 'game-changer' results

Regulators based their decision on data from the Phase 3 Profound study, which showed the drug could slash the risk of disease progression or death by 51% over next-gen therapies such as Johnson & Johnson’s Zytiga or Pfizer and Astellas’ Xtandi. Among patients with BRCA1, BRCA2 or ATM mutations specifically, that number was even higher, reaching 66%.

After unveiling those results at last September’s European Society for Medical Oncology (ESMO) annual meeting, AZ and Merck followed up last month with news that Lynparza had topped Zytiga and Xtandi at extending the lives of patients with BRCA1, BRCA2 or ATM mutations, too.

Those overall survival results made Lynparza a lock for an FDA OK, Leerink Partners analyst Andrew Berens wrote in a note to clients at the time. And it also gave the drug an advantage over rival drug Rubraca from Clovis Oncology, which nabbed a go-ahead in the previously treated metastatic, castration-resistant prostate cancer population late last week.

RELATED: Clovis' Rubraca nabs prostate cancer OK, but Big Pharma competition looms

“While approval was widely expected, this overall survival advantage was not anticipated, and we believe should prove to be a significant commercial advantage,” Berens wrote.

Study design may help boost Lynparza, as well, the way Berens sees it. “We also believe that Lynparza’s strong randomized data versus standard of care Xtandi or Zytiga may better facilitate reimbursement and uptake versus Rubraca’s single-arm study, especially with an overall survival advantage,” he noted.

The prostate cancer OK follows prior first-in-class nods for Lynparza in ovarian cancerbreast cancer and pancreatic cancer