Supernus Pharmaceuticals will acquire Sage Therapeutics in a deal worth up to $795 million, gaining access to the only postpartum depression pill approved in the United States, the companies said on Monday.

After Biogen failed with a takeover bid in January, Supernus has swooped in to acquire the postpartum depression pill developer.

Neurology specialist Supernus Pharmaceuticals will snap up Sage Therapeutics, which was once valued at more than $9 billion, for $561 million up front, with the hope that it can help transform a newly launched treatment for postpartum depression (PPD) into the indication's standard of care.