X0306 4 2018-08-06 0 0000730272 REPLIGEN CORP RGEN 0001270264 EDDLEMAN ROY T 1801 CENTURY PARK E. 16TH FLOOR LOS ANGELES CA 90067 0 0 1 0 Common stock 2018-08-06 4 S 0 33142 49.0495 D 796858 I As trustee Common stock 2018-08-07 4 S 0 16015 49.0526 D 413985 D Common stock 2018-08-08 4 S 0 4770 49.0504 D 409215 I As trustee Common stock 2903446 I As trustee Common stock 357518 D The price is a weighted-average price. The shares were sold in multiple transactions at prices ranging from $49.207 to $49.1358, inclusive. The reporting person undertakes to provide to the issuer, any security holder of the issuer, or the staff of the SEC, upon request, full information regarding the number of shares sold at each price with the price ranges set forth in this footnote and in footnote (3), below. The shares shown are held, of record, by a charitable remainder unitrust of which the reporting person is the sole trustee and, as such, has investment and voting control over such shares, and is a lifetime beneficiary. The reporting person disclaims as beneficial ownership of the shares except to the extent of his pecuniary interest therein. The price is a weighted-average price. The shares were sold in multiple transactions at prices ranging from $49.0500 to $49.0908, inclusive. The shares shown are held, of record, by a second charitable remainder unitrust of which the reporting person is the sole trustee and, as such, has investment and voting control over such shares, and is a lifetime beneficiary. The reporting person disclaims as beneficial ownership of the shares except to the extent of his pecuniary interest therein. The shares shown are held of record by the Roy T. Eddleman Living Trust UAD 8-7-2000, of which the reporting person is the sole trustee, and as such, has investment and voting control over such shares. The shares shown are held for the benefit of the reporting person in a 15-month escrow account established in connection with the acquisition of Spectrum, Inc. by the issuer on August 1, 2017 and are subject to potential indemnification claims of the issuer relating to the acquisition. Istvan Benko, as Attorney-in-Fact for Roy T. Eddleman 2018-08-08