REPLIGEN CORP — Director's Dealing 2017

May 22, 2017

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: REPLIGEN CORP (RGEN)
CIK: 0000730272
Period of Report: 2017-05-18

Reporting Person: COOPER GLENN L MD (Director)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2017-05-18	Common Stock	A	1206	—	Acquired	38300	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2017-05-18	Stock Option (Right to Buy)	$38.76	A	2434	Acquired	2027-05-18	Common Stock (2434)	Direct

Footnotes

F1: Dr. Cooper was awarded 1,206 Restricted Stock Units. Each Restricted Stock Unit represents a contingent right to receive one share of Repligen Corporation's Common Stock. The Restricted Stock Units vest on May 18, 2018. The Restricted Stock Units may be settled only by delivering shares of Repligen Corporation's Common Stock, and thus, the grant is being reported in Table 1 as allowed per SEC guidance.

F2: Award vests in full one year from grant date on May 18, 2018.