8-K

                       SECURITIES AND EXCHANGE COMMISSION

                                Washington, D.C.

                                    FORM 8-K

                                 CURRENT REPORT

                         Pursuant to Section 13 or 15(d)

                     of the Securities Exchange Act of 1934

       Date of Report (Date of Earliest Event Reported): December 31, 1997

                              Repligen Corporation
             (Exact name of registrant as specified in its charter)

          Delaware                     0-14656                   04-2729386 
(State or other jurisdiction   (Commission file number)      (I.R.S. Employer 
     of incorporation)                                      Identification No.)

117 Fourth Avenue
Needham, Massachusetts                            02194
(Address of principal executive offices)        (Zip Code)

Registrant's telephone number, including area code: (781)449-9560



ITEM 5.  OTHER EVENTS

On December 31, 1997, the Registrant publicly disseminated a press release
announcing a $2.0 million investment in the Company by Biotechnology Value Fund,
L.P. and affiliates ("BVF") of San Francisco and Four Partners, L.P. of New
York. The investment involves the sale of common stock and warrants. The press
release announcing the investment is incorporated herein by reference and filed
as Exhibit 99 hereto.

ITEM 7.  FINANCIAL STATEMENTS AND EXHIBITS

(c)     Exhibits.

        Exhibit 99    The Registrant's Press Release dated December 31, 1997.



                                    SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the
Registrant has duly caused this report to be signed on its behalf by the
undersigned hereunto duly authorized.

                                    Repligen Corporation
                                    (Registrant)


Date:   January 2, 1998             By: /S/ Walter C. Herlihy
                                        --------------------------
                                        Chief Executive Officer

                                    Signing on behalf of the Registrant
                                    and as Principal Financial and
                                    Accounting Officer



EXHIBIT INDEX

Exhibit Number          Description                         Sequential
                                                            Page Number

99                      The Registrant's Press Release      5
                        dated December 31, 1997

EX-99

CONTACT:
Walter C. Herlihy, Ph.D.
President and Chief Executive Officer
(781) 449-9560, ext. 2000

RELEASE: IMMEDIATE

                 Repligen Announces $2 Million Private Placement
                   Biotechnology Value Fund Invests in Company

Needham, MA --December 31, 1997 -- Repligen Corporation (Nasdaq: RGEN) today
announced a $2.0 million investment in the Company by Biotechnology Value Fund,
L.P. and affiliates (BVF) of San Francisco and Four Partners of New York. The
investment involves the sale of 2 million shares of common stock and warrants to
purchase an additional 750,000 shares of common stock at $1.50 per share.

      "This investment will enable the Company to accelerate the development of
our growth factor antagonists and expand our screening to additional targets,"
said Walter C. Herlihy, Ph.D., President and CEO of Repligen. "In addition, we
plan to increase our efforts to synthesize combinatorial chemical libraries
suitable for the discovery of inhibitors of clinically important protein-protein
interactions."

      Mark Lampert, President of BVF, Inc. stated, "Repligen has developed a
unique set of drug discovery technologies which have now been validated by the
identification of active lead compounds. We believe that the Company's
technology combined with strong corporate partners and low burn rate make this
an attractive investment."

        Following this investment the Company's cash position is approximately
$5,000,000. The Company expects to report an operating loss of approximately
$500,000 for the nine month period ended 12/31/97.

        Repligen develops high throughput screens to identify inhibitors of
important protein-protein and protein-carbohydrate interactions. These assays
include its Glyceptor(TM) screens for identification of inhibitors of
protein-heparan sulfate interactions and assays based on interaction of
signaling proteins with their receptors. The Company is also developing a
combinatorial chemical technology for the production of synthetic compounds with
the complexity of natural products which may provide a richer source of leads
for its targets than conventional libraries. Its corporate headquarters are
located at 117 Fourth Avenue, Needham, MA 02194. Additional information may be
obtained from www.repligen.com.

This press release contains forward-looking statements based on current
management expectations. There are certain key factors which could cause future
results to differ materially from those anticipated by management. Such factors
include, but are not limited to: the Company's ability to continue to establish
collaborative arrangements with third parties; the Company's ability to maintain
financial stability; the technical risks associated with development of new
products; the fact that there can be no assurances that patents relating to the
Company's potential products will afford adequate protection to the Company; the
risks of technological change and competition; and the competitive environment
of the biotechnology and pharmaceutical industries. These factors are more fully
discussed in the Company's periodic filings with the Securities and Exchange
Commission.
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