CAMBRIDGE, Mass.--(BUSINESS WIRE)--MPM Capital announces the appointment of Mitchell H. Finer PhD (Mitch) as Managing Director (MD). Mitch also serves on the Board of Directors of MPM’s portfolio company Semma Therapeutics, Inc.  Mitch's most recent role was as CSO of bluebird bio (NASDAQ: BLUE), a clinical-stage company committed to developing potentially transformative gene therapies for severe genetic and rare diseases. Mitch continues to serve on bluebird's scientific advisory board. In ann