8-K

                       SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549

                                    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 18, 2001

                          TRANSKARYOTIC THERAPIES, INC.
             (Exact Name of Registrant as Specified in its Charter)


                                    Delaware
                 (State or Other Jurisdiction of Incorporation)

           000-21481                                  04-3027191
    (Commission File Number)               (IRS Employer Identification No.)


195 Albany Street, Cambridge, Massachusetts             02139
 (Address of Principal Executive Offices)             (Zip Code)


                                 (617) 349-0200
               Registrant's Telephone Number, Including Area Code


                                 Not Applicable
          (Former Name or Former Address, if Changed Since Last Report)





Item 5. Other Events.

       On December 18, 2001, Transkaryotic Therapies, Inc. issued a press
release announcing the completion of its previously announced follow-on
public offering, raising a total of $125,580,000 before underwriting
discounts and commissions. A total of 3,220,000 shares of common stock were
sold at the public offering price of $39.00 per share, including 420,000
shares to cover overallotments. The joint bookrunning managers for the
offering were SG Cowen Securities Corporation and Deutsche Banc Alex. Brown
Inc. Co-managers of this offering were Pacific Growth Equities, Inc. and
Leerink Swann & Co. A copy of the press release is attached to this Current
Report on Form 8-K as Exhibit 99.1, and is incorporated herein by reference.

Item 7. Financial Statements, Pro Forma Financial Information and Exhibits.

       (c) Exhibits.

           99.1   Press Release, dated December 18, 2001.



                                      -2-




                                    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.

Date: December 18, 2001

                                         REGISTRANT

                                         TRANSKARYOTIC THERAPIES, INC.

                                         By: /s/ DANIEL E.  GEFFKEN
                                            ------------------------------------
                                            Daniel E.  Geffken
                                            Senior Vice President, Finance
                                            and Chief Financial Officer



                                      -3-




                                  EXHIBIT INDEX

EXHIBIT NUMBER          DESCRIPTION
- --------------          -----------

   99.1             Press Release, dated December 18, 2001.


                                      -4-

EX-99.1

                                                                    Exhibit 99.1



CONTACT:
Justine E. Koenigsberg
Director, Corporate Communications
(617) 349-0271

FOR IMMEDIATE RELEASE

           TKT ANNOUNCES EXERCISE OF OVERALLOTMENT OPTION

CAMBRIDGE, MA, DECEMBER 18, 2001-- Transkaryotic Therapies, Inc. (Nasdaq: TKTX)
today announced the completion of its previously announced follow-on public
offering, raising a total of $125,580,000. A total of 3,220,000 shares were sold
at $39.00 per share, including 420,000 shares to cover overallotments. The joint
bookrunning managers for the offering were SG Cowen Securities Corporation and
Deutsche Banc Alex. Brown. Co-managers of this offering were Pacific Growth
Equities, Inc. and Leerink Swann & Company.

Copies of the prospectus relating to this offering of common stock may be
obtained from SG Cowen Securiites Corporation through ADP by calling (631)
254-7106 or by fax at (631) 254-7140; Deutsche Banc Alex. Brown, Prospectus
Department, One South Street, Baltimore, MD 21202, (410) 895-2070, or from the
offices of any of the managing underwriters listed above.

A registration statement relating to these securities has been filed with and
declared effective by the Securities and Exchange Commission. This press release
shall not constitute an offer to sell or the solicitation of an offer to buy nor
shall there be any sale of these securities in any state in which such offer,
solicitation or sale would be unlawful prior to registration or qualification
under the securities laws of any such state.

ABOUT TKT
Transkaryotic Therapies, Inc. (TKT) is a biopharmaceutical company dedicated
to the development and commercialization of products based on its three
proprietary development platforms: Niche Protein(R) products,
Gene-Activated(R) proteins, and gene therapy. The Company's Niche Protein
product platform is based on protein replacement for the treatment of rare
genetic diseases, a group of disorders characterized by the absence of
certain metabolic enzymes. TKT's gene activation technology is a proprietary
approach to the large-scale production of therapeutic proteins, which does
not require the cloning of genes and their subsequent insertion into
non-human cell lines. The Company's gene therapy technology, known as
Transkaryotic Therapy(TM), is focused on the commercialization of non-viral,
EX VIVO gene therapy products for the long-term treatment of chronic protein
deficiency states.

GENE-ACTIVATED(R), NICHE PROTEIN(R), AND TKT(R) ARE REGISTERED TRADEMARKS AND
TRANSKARYOTIC THERAPY(TM) IS A TRADEMARK OF TRANSKARYOTIC THERAPIES, INC.

PLEASE VISIT OUR WEB SITE AT WWW.TKTX.COM FOR ADDITIONAL INFORMATION ABOUT
TRANSKARYOTIC THERAPIES, INC.
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