San Francisco, Calif.-based pharmaceutical company Actelion will acquire Ceptaris Therapeutics, contingent upon certain closing conditions, including FDA approval of Ceptaris' product, VALCHLOR.

If approved, VALCHLOR would be the first topical formulation of mechlorethamine for the treatment of early-stage mycosis fungoides-type cutaneous T-cell lymphoma.

Actelion paid $25 million upon signing and will pay $225 million upon closing. Ceptaris' shareholders also are eligible to receive additional payments based on net sales of VALCHLOR and the achievement of certain commercial milestones.

"Should the FDA approve VALCHLOR and Actelion acquire Ceptaris, we would be able to offer this medicine to patients who are dependent on formulations prepared locally by compounding pharmacies in a non-standardized environment,” said Jean-Paul Clozel, M.D., and chief executive of Actelion. “At the same time, we would leverage our existing knowhow and infrastructure in the fields of orphan and ultra-orphan indications when appropriately commercializing VALCHLOR to specialists in the field of dermatology and oncology."