GSK will stop selling the drug Zejula for some ovarian cancer patients whose disease is stable after a second line of chemotherapy, the company said Friday, following pressure from the Food and Drug Administration to pull the medicine from the market in that setting.
The decision is the latest setback for a group of drugs known as PARP inhibitors that have been approved in recent years for ovarian cancer and other tumors. Recent studies have shown that those drugs don’t help late-line ovarian patients with a certain cancer-associated gene mutation live longer, and in Zejula’s case, might put a particular group of second-line patients at a numerically higher risk of death.
Those findings have led to a recent string of withdrawals of PARP inhibitors in certain indications.
AstraZeneca and Merck & Co.’s Lynparza, for instance, is no longer used in patients with BRCA mutations and whose cancers have progressed after three lines of chemotherapy. Clovis Oncology’s Rubraca has been pulled off the market for a similar group of patients who’ve received two lines of chemo. Both drugs got to market via accelerated approvals in those indications, raising more questions about a program that has already drawn significant scrutiny from lawmakers.
In Zejula’s case, the drug will only remain on the market in second-line “maintenance” use — a setting aimed at keeping the disease from returning after a successful round of chemotherapy — in patients with a suspected or confirmed BRCA mutation.
GSK based its decision on the findings of a Phase 3 trial which found that Zejula didn’t help patients without BRCA mutations live longer when compared to a placebo after two rounds of chemo. The FDA originally scheduled an advisory committee meeting to discuss the data, but canceled the hearing as a result of GSK’s announcement.
In September, GSK also withdrew Zejula in a different subset of patients. It remains available as a maintenance treatment for ovarian and related cancers in all patients who have responded to one round of chemotherapy, however.
GSK acquired Zejula when it bought Tesaro for $5.1 billion in 2018. It recorded sales of 395 million pounds, or about $543 million, in 2021, and through nine months of 2022 sales were 338 million pounds, or roughly $418 million. Sales of Lynparza, the top-selling PARP inhibitor, have also recently trended downward, missing consensus estimates in the third quarter.
The increased FDA scrutiny may be causing some physicians curtail use of PARP inhibitors, SVB Securities analyst Andrew Berens wrote in a Nov. 10 note.
Berens believes the lower-than-expected sales “may reflect some regulatory concerns regarding the PARP class impact on overall survival outside of BRCA [positive] patients in later lines of therapy in ovarian cancer.”
“While the PARP agents have largely moved to earlier lines of therapy in ovarian cancer, it is possible that these concerns are weighing on broad usage of the drugs,” he wrote.