Marlborough biotech Sunovion Pharmaceuticals Inc. is preparing to start selling a new antiseizure pill early next year, following Food and Drug Administration approval of the medication.
FDA regulators signed off on Sunovion’s first epilepsy drug, called Aptiom, on Friday, giving the Japanese-owned company its ninth approved medicine. Those already on the market treat conditions ranging from asthma and insomnia to schizophrenia and bipolar depression.
“This is one of our growth drivers,” Sunovion’s chief commercial officer, Rick Russell, said of the new drug to treat partial seizures. “It will be a significant part of our future.”
It was the second drug approval in the past five months for Sunovion, a company formerly known as Sepracor Inc. that was purchased for $2.6 billion in 2009 by Japan’s Dainippon Sumitomo Pharma Co. In June, the Marlborough company won FDA approval to use its already approved schizophrenia drug Latuda to treat bipolar depression.
Sunovion’s success — it was followed by an FDA decision Monday to fast-track review of a drug developed by Alnylam Pharmaceuticals Inc., of Cambridge, to treat the neurological disorder polyneuropathy — came as a welcome respite from a string of setbacks for Massachusetts biotechs in recent weeks. On Friday, an FDA staff report suggested a multiple sclerosis drug developed by Cambridge-based Genzyme might be too dangerous to approve.
Earlier last week, Ariad Pharmaceuticals Inc. laid off 160 people — 40 percent of its US workforce — after the Cambridge company was forced to stop marketing its leukemia drug because some patients taking the treatment in a clinical trial suffered blood clots and heart problems.
Also last week, the Waltham biotech ImmunoGen Inc. halted a mid-stage study of a small-cell lung cancer drug candidate after it was linked to infections and infection-related deaths.
Aptiom was approved by the Food and Drug Administration as an add-on drug to treat partial-onset epilepsy in patients who already are taking other antiseizure medications.
And the FDA placed a partial clinical hold on an early-stage trial of an experimental cancer drug developed by Curis Inc., following a patient’s death from liver failure. That stopped the Lexington biotech from enrolling new patients in the trial.
Late last month, Vertex Pharmaceuticals Inc., which will move from Cambridge to Boston starting in December, said it will cut about 370 jobs globally, including 175 in Massachusetts, because sales of its hepatitis C drug are declining faster than initially anticipated.
While keeping a lower profile than other Massachusetts biotechnology companies, Sunovion has been building up a portfolio of medicines to treat respiratory diseases and central nervous system disorders.
It has about 1,400 employees, including 600 at its Marlborough headquarters, 100 at a clinical development site in Fort Lee, N.J., and a sales force scattered across the United States and Canada.
A sister company, the cancer drug maker Boston Biomedical Inc., also owned by Dainippon, employs about 100 people in Cambridge.
But the best-selling Sunovion drug, Lunesta, a treatment for insomnia, faces the loss of its patent next spring, creating the need for new medicines to maintain the company’s annual sales of about $1.4 billion. With the growing market for Latuda, and the new approval for Aptiom, Russell said Sunovion is well positioned to continue its expansion.
Aptiom was approved by the FDA as an add-on drug to treat partial-onset epilepsy in patients who already are taking other antiseizure medications.
“Some patients with epilepsy do not achieve satisfactory seizure control from existing treatments,” said Dr. Eric Bastings, acting director of the FDA Center for Drug Evaluation’s neurology products division.
Russell said Sunovion is studying the use of the once-daily pill to treat newly diagnosed patients who have partial seizures. It plans to file a supplemental application with the FDA in the first half of next year to win Aptiom’s approval as a so-called first-line therapy.
“It’s an important option for patients,” Russell said. “This is a significant, serious disease. The partial onset seizures are the most common, and it’s important to help patients bring these seizures under control.”
Epilepsy is a brain disorder caused by abnormal activity in the brain’s nerve cells. About 200,000 new cases occur in the United States every year, according to the FDA.
The market for drugs that treat epilepsy has been estimated at about $2.5 billion annually. Drugs treating partial seizures represent roughly 60 percent of that market.Robert Weisman can be reached at email@example.com. Follow him on Twitter @GlobeRobW.