Novartis AG has entered an agreement to acquire Calypso Biotech BV, a developer of Interleukin15 (IL-15) targeted therapies, for $250 million upfront upon closing and potential development milestones of up to $175 million.   Calypso, a spin-out from Merck, is focused on the research and development of monoclonal antibodies for an array of autoimmune indications, with an expertise in IL-15 biology. IL-15 is a broad, untapped immune axis that controls barrier function and downstream immune casca...