AstraZeneca and Merck & Co have been awarded FDA approval for Lynparza in BRCA-positive advanced breast cancer – the first drug in the PARP inhibitor class to be approved outside ovarian cancer.
The US regulator has given the go-ahead for Lynparza (olaparib) for patients with HER2-negative tumours with BRCA mutations who have been previously treated with chemotherapy. The drug can also be used in hormone receptor-positive breast cancer if the patient has previously been treated with, or is not a candidate for, hormonal therapies. Patients are selected for treatment based on a diagnostic test made by Myriad Genetics.
In the OLYMPIAD trial, Lynparza achieved a statistically-significant and clinically-meaningful improvement in progression-free survival (PFS) compared to standard chemotherapy (with capecitabine, vinorelbine or eribulin). At a median follow-up of 14 months, PFS was 2.8 months longer and the risk for disease progression or death was 42% lower with olaparib monotherapy than with chemotherapy.
“This approval demonstrates the current paradigm of developing drugs that target the underlying genetic causes of a cancer, often across cancer types,” commented Richard Pazdur, who heads the FDA’s Office of Haematology and Oncology Products. Approximately 5-10% of patients with breast cancer have a BRCA mutation.
Approval beyond ovarian cancer is a big hurdle cleared for Lynparza as it tries to keep pace in the market with newer PARP inhibitor entrants Rubraca (rucaparib) from Clovis Oncology and Johnson & Johnson/Tesaro’s Zejula (niraparib).
Its first-mover position has also been helped by approval for maintenance therapy in ovarian cancer, as well as a change in formulation to a tablet version which requires fewer doses, as it faces a strong challenge from Zejula, which has seen rapid take-up after approval in part because its label did not require ovarian cancer patients to be tested for their BRCA status.
Merck (known as MSD outside the US and Canada) got involved in the Lynparza programme last year when it formed an $8.5bn strategic oncology collaboration with AZ that involves the co-development and co-commercialisation of Lynparza, and will also see its PD-1 blocker Keytruda (pembrolizumab) tested alongside Lynparza in a wide range of tumour types.