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Tesaro’s ovarian cancer drug wins early approval

The Food and Drug Administration approved a new drug to treat ovarian cancer developed by Tesaro Inc. of Waltham.Associated Press

Early approval of an innovative new drug to treat ovarian cancer Monday provided new hope to tens of thousands of American women suffering from recurrent forms of the disease — and gave a huge boost to Tesaro Inc., the Waltham biotech that developed the medicine.

The drug, which will be launched in the United States next month under the brand name Zejula, significantly increased patient survival rates in a late-stage clinical trial whose findings were reported last year. Food and Drug Administration regulators, who gave Zejula a priority review, were scheduled to rule on Tesaro’s new drug application by late June, but issued their decision three months early — an unusually quick turnaround.


Their action underscores the urgent need to find new ways to treat ovarian cancer, a disease for which there are few medical options. Each year, about 22,000 women are diagnosed with ovarian cancer in the United States and more than 65,000 women in Europe. It’s the fifth most frequent cause of cancer death in women, and the cancer recurs in 85 percent of patients within two years of chemotherapy.

Tesaro president Mary Lynne Hedley said in an interview that between 20,000 and 25,000 patients on both sides of the Atlantic will initially be eligible to take Zejula. That number will eventually expand as the company seeks approval in Asia, the Middle East, and elsewhere, she said.

“The speed with which [the FDA] moved speaks to the fact that patients really need something,” Hedley said. “They worked hard to expedite their review, and we worked with them.”

Analysts have projected Zejula could quickly become a so-called blockbuster treatment, generating annual sales topping $1 billion. Some project Tesaro, which has been the subject of takeover rumors in recent weeks, eventually could ring up sales of more than $5 billion a year from the drug.


Hedley told stock analysts that the drug had been approved for a “broad population” of women with recurrent ovarian cancer, but Tesaro plans to test the drug compound in other cancer patients starting later this year. If successful, more drug approvals could follow in the next three to four years, she said.

She declined to comment on takeover rumors that have been circulating around Tesaro — sending its stock price soaring — saying, “We’re here to develop drugs and make the lives of patients with cancer better. From our perspective, this is the beginning.”

“This is wonderful news for the ovarian cancer community,” Hedley said in a conference call with stock analysts. “We are gratified to be in a position to introduce this product to a broad population of patients.”

Zejula, a once-a-day pill, is part of a new class of medicines, called PARP inhibitors, that work by preventing cancer cells from replenishing their DNA.

It was approved by the FDA to treat women with recurrent epithelial ovarian, fallopian tube, or primary peritoneal cancer after they’ve had chemotherapy.

It’s seven-year-old Tesaro’s second approved drug. Regulators in 2015 approved Varubi, a treatment for nausea and vomiting induced by chemotherapy in lung, breast, and ovarian cancer patients, helping them tolerate treatments.

Tesaro executives said Monday that they plan to expand their development program for niraparib, the scientific name of Zejula, to test the compound in patients with lung cancer and metastatic forms of ovarian and breast cancers.


Shares of Tesaro were up nearly 6 percent in after-market trading. Trading in the stock was temporarily halted late Monday afternoon after the FDA approval was announced. Its market cap now stands at $9.4 billion.

The company won’t have the market to itself. British drug makers AstraZeneca Inc. recently reported positive clinical results for a rival PARP inhibitor that also treats ovarian cancer, but targets a narrower set of patients. Tesaro chief executive Lonnie Moulder told analysts that his company would disclose the list price of Zejula when it formally launches the drug next month.

Tesaro, which has about 400 employees, was founded in 2010 by Moulder and Hedley, with financial backing from Menlo Park, Calif., venture capital firm New Enterprise Associates. The company raised $81 million in a 2012 initial public offering and has raised more than $1 billion in public and private capital for its drug development.

Robert Weisman can be reached at Follow him on Twitter @GlobeRobW.