Cytokinetics Inc.'s deal with Astellas Pharma Inc. to develop skeletal muscle activators for weakness-related disorders preserves rights to tirasemtiv for the biotech firm, and focuses on the follow-on compound, CK-212707 (or CK-107, as it's more often known), providing $40 million for Cytokinetics during the first two years, with potential milestone payments up to $450 million.