X0306 4 2018-05-16 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 2018-05-16 4 S 0 118850 42.07 D 2925976 I As trustee Common Stock 830000 I As trustee Common Stock 430000 I As trustee Common Stock 357518 D The transaction involved the contribution by the reporting person of shares of the Issuer to an exchange fund in exchange for an interest in the exchange fund. The shares were valued at $42.07 per share for purposes of determining the amount of the exchange fund interest received by the reporting person. 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, 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 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 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. /s/ Istvan Benko, Attorney-in-fact for Roy T. Eddleman 2018-05-18