| This Schedule 13G/A is being jointly filed by Partner Fund Management, L.P. (“PFM”), Partner Fund Management GP, LLC (“PFM-GP”), Partner Investment Management, L.P. (“PIM”), Partner Investment Management GP, LLC (“PIM-GP”), Brian D. Grossman (“Grossman”) and Christopher M. James (“James” and, collectively with PFM, PFM-GP, PIM, PIM-GP and Grossman, the “Reporting Persons”) with respect to shares of common stock of the above-named issuer owned by PFM Healthcare Master Fund, L.P., a Cayman Islands limited partnership (“HCM”), PFM Healthcare Opportunities Master Fund, L.P., a Cayman Islands limited partnership (“HCOPP”), PFM Healthcare Principals Fund, L.P., a Delaware limited partnership (“HCP”), PFM Global Long Alpha Master Fund, L.P., a Cayman Islands limited partnership (“GLAF”), PFM Diversified Principals Fund, L.P., a Delaware limited partnership (“DP”), PFM Healthcare Emerging Growth Master Fund, L.P., a Cayman Islands limited partnership (“HEGM”), and PFM Diversified Master Fund, L.P., a Cayman Islands limited partnership (“DM” and, collectively with HCM, HCOPP, HCP, GLAF, DP and HEGM, the “Funds”). |