Passed up for acquisition by former partner Retrophin Inc., Censa Pharmaceuticals Inc. has found a new home in rare disease specialist PTC Therapeutics Inc., which has agreed to pay $10 million up front for the opportunity to develop CNSA-001 (sepiapterin), a candidate for orphan metabolic diseases, starting with phenylketonuria (PKU). The proposed transaction also includes up to 850,000 shares of PTC common stock (NASDAQ:PTCT), valued around $40 million, plus additional rewards for achieving development, regulatory and commercial milestones. Shares of PTC closed at $46.91 on May 7, down $1.31.