Thousand Oaks-based Amgen Inc. will collaborate with Abilita Bio, a privately held biotech company in San Diego focused on discovery and development of drugs targeting membrane proteins, according to a press release Wednesday. Financial terms were not disclosed in the release. “This exciting new collaboration aims at tackling some of the unique challenges that have limited the success of discovering and developing drugs targeting complex membrane proteins,” said Mauro Mileni, chief executive of Abilita Bio. “Amgen helped define the field of biotechnology and has driven innovation through outstanding science. We look forward to working with their exceptional research teams to drive tough projects forward.”