Paratek Pharmaceuticals, Inc. will receive a $4 million milestone payment from Actavis under the companies’ sarecycline (WC3035) development collaboration. Actavis has initiated Phase III trials of sarecycline in moderate to severe acne. Paratek is eligible for additional regulatory and commercialization milestones, including NDA acceptance, approval, and royalties on sales.   The companies entered the exclusive collaboration for sarecycline in July 2007. Paratek designed and developed sarecycli...