AstraZeneca’s Lynparza honed its edge in ovarian cancer on Tuesday, and just in time to help preserve its lead in the marketplace.
In detailed results from a test of the drug in patients who’d relapsed after platinum chemo, the first-in-class PARP inhibitor held off cancer recurrence by more than two years, compared with placebo, and delivered a statistically significant improvement in the risk of tumor progression or death.
Those numbers compare favorably with Tesaro’s much-ballyhooed competitor niraparib, which delivered a 15.5-month survival advantage in its own maintenance-therapy trial presented last fall. Tesaro's shares were down Tuesday afternoon by more than 11% on the news.
AstraZeneca’s Solo-2 trial tested Lynparza (olaparib) against placebo in 295 patients who tested positive for the BRCA gene. In a Blinded Independent Central Review (BICR) evaluation, it showed the drug delivering a median 30 months before patients’ tumors grew again, compared with just 5.5 months for patients in the placebo arm—a progression-free survival advantage of 24.5 months. The investigator-assisted analysis put median PFS at 19.9 months, compared with 5.5 months for placebo.
With Clovis Oncology’s rival drug Rubraca now approved, and niraparib due for an FDA decision in June, the strong showing is good news for AstraZeneca, competitively speaking. And beyond the niraparib-beating numbers that could help Lynparza keep a leg up on its future rival, the new study might persuade regulators to broaden the drug’s approval.
A new maintenance-therapy indication in the U.S. would not only give a new group of women access to Lynparza, but would also allow patients to stay on treatment for longer periods of time, leading to higher sales. Lynparza already has a maintenance approval in Europe, and its capsule formulation has put up positive data in the same setting, but right now it’s approved for stateside ovarian cancer patients only after treatment with three or more other agents.
AstraZeneca Chief Medical Officer Sean Bohen, M.D., Ph.D., said in a statement that the company is “extremely pleased with the results” from Solo-2, which were unveiled Tuesday at the Society of Gynecologic Oncology meeting in Maryland.
The data “support the potential benefit of Lynparza tablets as a maintenance therapy for patients with relapsed ovarian cancer,” Bohen said, adding that the tablets used in the study—as opposed to the currently approved capsule formulation—may cut the number of pills patients need to take daily.
“We will work with regulatory authorities to make Lynparza tablets available to patients as quickly as possible,” he said.
AstraZeneca is also testing Lynparza in other cancers, including breast cancer, where it put up solid data last month. Phase 3 results showed that Lynparza could top standard-of-care chemo at increasing progression-free survival in patients with HER2-negative breast cancer and BRCA1 or BRCA2 mutations. Bohen pointed out at the time that the numbers were the first positive phase 3 data for any PARP med outside the ovarian cancer arena.