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AZ, Merck’s latest Lynparza combo win could widen its ovarian cancer reach

Lynparza bottle
The PARP inhibitor Lynparza is in a three-way market battle with GSK’s Zejula and Clovis’ Rubraca. (AstraZeneca)

In the red-hot market for PARP inhibitors, AstraZeneca and Merck’s contender Lynparza is ahead of rival products from GlaxoSmithKline and Clovis Oncology—but not comfortably ahead. That may change, though, thanks to news from a key clinical trial in ovarian cancer that the partners released today.

In a phase 3 trial, a combination of Lynparza and Roche’s Avastin (bevacizumab) topped Avastin alone at staving off cancer progression in women receiving maintenance therapy after an initial round of chemo. And it did so in women with or without BRCA mutations. Avastin is the current standard of care for first-line maintenance in ovarian cancer, so AZ and Merck have a lot to gain if Lynparza’s label is expanded so the drug can be added to that treatment.

The company will release the data from the trial at an upcoming medical meeting and will be “discussing the results with global health authorities as soon as possible,” José Baselga, executive vice president of oncology R&D at AZ, said in a statement.

The news came just a month after PARP rival GSK released data from its own phase 3 trial showing that its drug, Zejula, bested placebo in the first-line ovarian cancer maintenance setting—also regardless of BRCA status. GSK paid $5.1 billion to acquire Zejula’s maker, Tesaro, earlier this year, so the fresh data was considered a major win for the company.

Lynparza already has one FDA approval in the first-line ovarian cancer maintenance setting, for women with germline or somatic BRCA mutations. AZ and Merck won that approval with data showing the drug reduced the risk of disease progression or death by a remarkable 70%.

An additional maintenance approval in ovarian cancer patients with or without BRCA mutations could fuel what has already been a strong run for Lynparza. The drug hauled in $283 million in sales in the second quarter, beating analysts’ expectations and helping drive revenues from AZ’s oncology unit up 51% to $2.17 billion. The ovarian cancer maintenance market could be worth as much as $2.5 billion, Evercore ISI estimated last year.

Late last month, AZ got a leg up in the overseas ovarian cancer market when England’s cost watchdog, the National Institute for Health and Care Excellence (NICE), recommended the drug for maintenance use in BRCA mutation-positive ovarian cancer. There were some limitations imposed—the agency said it needs more survival data to make a full recommendation—but the nod was still seen as a positive for AZ as it seeks to maintain its PARP lead.

All of the PARP contenders are looking to boost their potential markets by investigating the potential of the drugs in other cancers, too. Just last week, AZ and Merck made a strong case that they should pioneer the market for PARP inhibitors in prostate cancer. The companies announced positive results from a phase 3 trial of Lynparza in men with metastatic castration-resistant prostate cancer and a mutation in BRCA1, BRCA2 or one of 13 other related genes.

But even if AZ and Merck become the first to enter the prostate cancer market, they’ll always be looking over their shoulders at their PARP rivals. Clovis earned breakthrough designation for its PARP drug Rubraca in prostate cancer last year, and Zejula is also making strides towards that market.