Last month Allergan announced its plan to acquire Fort Washington, Pennsylvania–based Vitae Pharmaceuticals for $639 million or about $21 per share—a 159% premium over the autoimmune drug developer's close of $8.10 the day before the announcement.Dublin-based Allergan said that adding Vitae's lead product, VTP-43742, will strengthen the company's dermatology product pipeline. A first-in-class, oral retinoic-acid-receptor-related, orphan nuclear receptor gamma (RORγt) inhibitor for treating psoriasis and other autoimmune disorders, VTP-43742 acts by inhibiting interleukin 17 secretion from T-helper 17 cells and blocking the action of IL-23. Vitae recently completed a phase 2 proof-of-concept trial in patients with moderate to severe psoriasis with the small-molecule inhibitor, and is expected to start a larger, longer phase 2 study this year, with results due in the second half of 2017. The acquisition also adds VTP-38543, a topical liver X receptor beta (LXRβ) selective agonist currently in a phase 2a proof-of-concept clinical trial for treating atopic dermatitis, as well as Vitae's Contour structure-based drug design platform for discovering product candidates for challenging therapeutic targets. Allergan's medical dermatology franchise currently includes Tazorac (tazarotene) for acne and psoriasis, Botox (onabotulinumtoxinA) for hyperhidrosis and acne vulgaris gel Aczone (dapsone). Such treatments make up one of the drug industry's biggest markets, worth nearly $49 billion in worldwide sales last year.