Europe is broadening the use of Lynparza as the FDA examines the PARP drugs | Popgen Tech
European drug regulators have accused AstraZeneca and Merck & Co. approved Lynparza for patients newly diagnosed with advanced prostate cancer, days after the Food and Drug Administration delayed a decision on the same use.
The European Commission on Wednesday approved a regimen of Lynparza, hormone therapy and steroids for adults with metastatic castration-resistant prostate cancer and who are not eligible for chemotherapy. Lynparza is already marketed in Europe, as well as the US, for later use. The new approval allows it to be used earlier, broadening its market.
In clearing Lynparza, Europe is moving ahead of the US. The FDA last week delayed a decision on approval by three months to “allow further time for a full review” of the data underlying the application, AstraZeneca said in a statement at the time. In November, the main medicines review office of the European Medicines Agency recommended approval based on the same data.
The departure comes as the FDA appears to be investigating drugs such as Lynparza, known as PARP inhibitors, that target an enzyme used to repair DNA.
Multiple PARP blockers have reached the market for ovarian, breast, pancreatic and prostate tumors. They are often used as “maintenance therapy” — meant to slow the return of cancer when a tumor is surgically removed or eradicated by other drugs — but have begun to work in earlier lines of care. Lynparza was the group’s top seller, earning $2.3 billion for AstraZeneca last year and nearly $1 billion for Merck.
But in recent months, studies have shown that PARP inhibitors do not help certain heavily pretreated ovarian cancer patients live longer and in some cases may put some at greater risk of death.
Since June, AstraZeneca and Merck, GSK and Clovis Oncology have each withdrawn their drugs in certain ovarian cancer indications in the US. For example, Lynparza is no longer used in patients with so-called BRCA mutations and whose cancers after three rounds of chemotherapy. Clovis’s Rubraca was withdrawn from the market in similar patients receiving two lines of chemo, and GSK’s Zejula was also withdrawn from certain second-line use.
The regulatory concerns could have a sales impact. Last quarter, Lynparza missed consensus analyst estimates, which SVB Securities analyst Andrew Berens attributed to doctors possibly limiting the use of PARPs in ovarian cancer.
Against this background, the FDA’s review extension for AstraZeneca and Merck’s latest application in prostate cancer has attracted more attention. The companies’ submission is based on a Phase 3 study in which a Lynparza-based regimen kept tumors in check longer, regardless of patients’ underlying genetics, than a combination of hormone therapy and steroids.
The results, published last year in The New England Journal of Medicine, also showed a 34% reduction in the risk of disease progression or death. But AstraZeneca and Merck have yet to prove that the drug regimen has extended patients’ lives.
“Given some of the emerging concerns about the PARP inhibitor class, we think it is possible that the FDA has asked [AstraZeneca] for more information” on survival data and trends, Berens wrote in a client note last week, adding that the FDA may be concerned about the risk/benefit profile of PARPs in certain patient subgroups.
AstraZenenca and Merck said they would “continue to work with the FDA to facilitate the completion of the review”.