Cephalon has signed an agreement with Ception Therapeutics giving it an option to buy the privately held biopharmaceutical company and get access to its late-stage monoclonal antibody reslizumab.

Under the terms of the deal, Cephalon will pay Ception a $100 million upfront option payment and if it exercises the option, $250 million for all of the Malvern, Pennsylvania-based firm's outstanding shares. Whether Cephalon goes through with the deal will depend on how reslizumab, a mAb against interleukin-5 progresses in the clinic.

The compound is currently in a Phase IIb/III trial for the treatment of paediatric eosinophilic oesophagitis, an allergic inflammation of the gullet. Symptoms of the disorder include vomiting, chest pain, difficulty eating, and characteristics that mimic severe gastro-oesophageal reflux disease. Reslizumab is also in Phase II for the treatment of eosinophilic asthma in adults.

Cephalon chief executive Frank Baldino said that the deal creates the opportunity for the company to introduce its first biologic into the market. He added that the addition of biologics, “which have a longer commercial life, will add higher value products to our portfolio...which are first-in-class”.