GlaxoSmithKline has exercised its option to obtain an exclusive, worldwide license to products associated with an undisclosed muscle disease target discovered using Five Prime Therapeutics screening and discovery capabilities. Five Prime will receive a $1.5 million exercise fee and is entitled to receive as much as $122.5 million in preclinical, development and commercial-related milestones and royalties on sales.   The companies entered the collaboration in 2010 for the discovery, development a...