X0306 4/A 2018-05-08 2018-05-09 0 0000730272 REPLIGEN CORP RGEN 0001270264 EDDLEMAN ROY T C/O TROYGOULD PC 1801 CENTURY PARK E., 16TH FLOOR LOS ANGELES CA 90067 0 0 1 0 Common Stock 2018-05-08 4 S 0 49227 40.77 D 850773 I As trustee Common Stock 2018-05-08 4 S 0 25000 40.66 D 455000 I As trustee Common Stock 2018-05-09 4 S 0 20773 40.52 D 830000 I As trustee Common Stock 2018-05-09 4 S 0 25000 40.37 D 430000 I As trustee Common Stock 357518 D Common Stock 3044826 I As trustee The price is a weighted-average price. The shares were sold in multiple transactions at prices ranging from $40.5515 to $41.0078, 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 within the price ranges set forth in this footnote (1) and in footnotes (3) - (5) to this Form 4. 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 $40.5607 to $41.0107, inclusive. The shares shown are held, of record, by another 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 $40.2401 to $40.70, inclusive. The price is a weighted-average price. The shares were sold in multiple transactions at prices ranging from $40.2102 to $40.6022, inclusive. 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. 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. /s/ Istvan Benko, Attorney-in-fact for Roy T. Eddleman 2018-05-10