X0306 4/A 2016-11-18 2016-11-21 0 0001280600 ACCELERON PHARMA INC XLRN 0001117003 MCGUIRE TERRANCE ONE MARINA PARK DRIVE, SUITE 1100 BOSTON MA 02210 1 0 0 0 Common Stock 0 D On November 21, 2016, due to a clerical error, the Reporting Person inadvertently filed a Form 4 reporting the receipt of 1,624 shares pursuant to a pro rata distribution, and not a purchase or sale, without additional consideration by Polaris Venture Management IV, L.L.C. to its members and assignees. As of November 18, 2016, the Reporting Person held 0 shares of the Issuer's common stock. This amendment corrects this clerical error. /s/ Terrance McGuire 2017-03-08