Abbvie Inc. agreed to pay Boehringer Ingelheim GmbH $595 million up front for the opportunity to co-develop and later sell BI 655066, a phase III anti-IL-23 monoclonal antibody for psoriasis that could eventually help the North Chicago-based company replace revenue losses that it will face as its largest product, Humira (adalimumab), begins to lose patent protection and incur competition from biosimilars.