Marlborough biotech Sunovion Pharmaceuticals Inc. said Thursday that it will pay $624 million to acquire Toronto-based Cynapsus Therapeutics Inc., in a deal that gives Sunovion a promising experimental drug to treat a common complication from Parkinson's disease.
The buyout, approved by the boards of both companies, will be funded by cash on hand at Sunovion, which is owned by Japan's giant Sumitomo Dainippon Pharma Group.
Sunovion already markets nine approved therapies treating respiratory conditions and central nervous system disorders. Last year, the Food and Drug Administration approved its Aptiom epilepsy tablet to treat hundreds of thousands of Americans suffering from a type of seizure. Last month, Sunovion applied for FDA approval of a drug-device combination to treat airflow obstruction in patients with chronic obstructive pulmonary disease, or COPD.
The purchase of Cynapsus will expand Sunovion's portfolio into the field of neurology. Cynapsus' leading drug candidate, called APL-130277, is being tested in a late-stage clinical trial of Parkinson's patients suffering so-called OFF episodes, debilitating periods lasting 30 minutes or longer when they experience loss of motor functions, leaving them unable to stand, sit, or walk.
"Sunovion will be well positioned to treat this condition, which affects millions of people around the world," Dr. Antony Loebel, the Sunovion executive vice president and chief medical officer, said in an interview.
The treatment, which is administered through a strip placed under patients' tongues, does not treat the underlying disease. Parkinson's, the second most prevalent neurodegenerative disorder after Alzheimer's, affects at least 1 million patients in the United States and at least 4 million globally. More than half eventually experience disabling OFF episodes.
An injectable drug called Apokyn has been approved by the FDA to treat Parkinson-related OFF episodes, but the Cynapsus experimental drug would be the first oral treatment.
Sunovion has more than 1,500 employees worldwide, about a third of them in Marlborough. It is expected to complete its acquisition of Cynapsus in the fourth quarter.
Robert Weisman can be reached at firstname.lastname@example.org. Follow him on Twitter @GlobeRobW.