Dreier LLP Announces Class Action Lawsuit Against Vertex Pharmaceuticals Incorporated(VRTX) f trusts and estates law. Pitta & Dreier LLP is an affiliate which specializes in labor law, and Pitta, Bishop, Del Giorno & Dreier LLP specializes in government relations. In the 12 years since its founding, Dreier LLP, with its affiliate members, has grown to more than 200 attorneys, with its principal office at 499 Park Avenue in Manhattan, and additional offices in Los Angeles ...