- The Food and Drug Administration will convene an expert panel in April to review use Merck & Co. and AstraZeneca’s Lynparza in patients newly diagnosed with advanced prostate cancer, the companies said Thursday.
- A positive vote could help make Lynparza the first among a group of medicines known as PARP inhibitors to be used in the U.S. as a first-line treatment for metastatic prostate cancer patients. But the FDA has already delayed a decision, and the companies recently revealed that the drug, when used alongside other therapies, didn’t significantly extend survival in late-stage testing.
- Lynparza is an important growth driver for AstraZeneca, earning it nearly $3 billion in sales and partnership revenue in 2022 from its use in ovarian, breast, pancreatic and advanced prostate cancer. Merck received more than $1 billion in revenue from Lynparza last year via a partnership the two struck in 2017.
Already approved in Europe as a frontline treatment for prostate cancer, Lynparza has faced a tougher test in the U.S. AstraZeneca and Merck expected an FDA decision by the end of 2022, but have since seen the regulator defer a ruling and must now present their case to an advisory committee on April 28.
The outcome of that meeting, as well as the FDA’s decision, could be worth billions of dollars to both companies.
While Lynparza is already approved in the U.S. for later-line use in prostate cancer, an approval in earlier settings could significantly broaden its reach. To obtain that outcome, Merck and AstraZeneca are relying on a study known as PROpel, in which a Lynparza-based regimen held tumors in check, regardless of patients’ underlying genetics, longer than a combination of hormone therapy and steroids.
But a final analysis presented at a medical meeting last month showed the drug combination didn’t lead to a statistically significant benefit in survival, and that the results for certain subgroups were worse than for all comers. In a research note Thursday, SVB Securities analyst Andrew Berens suggested the FDA meeting might have been called because of those findings.
Already, the FDA has recently upped its scrutiny of PARP inhibitors. AstraZeneca and Merck, GSK and Clovis Oncology have each withdrawn their drugs in certain ovarian cancer indications in the U.S. following results showing the drugs don’t help certain heavily pretreated patients live longer and, in some cases, may put some at a higher risk of death.
Berens wrote that the agency might now be reluctant to approve Lynparza for all patients with prostate cancer, too. If Lynparza’s label is limited, Berens estimates that its peak annual sales in prostate cancer could be cut in half, from more than $4 billion to about $2 billion.
The advisory committee’s discussion also could also have implications for Pfizer, whose rival PARP blocker Talzenna produced positive Phase 3 data last month.