SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM 10-Q/A
AMENDMENT NO. 1

ý	QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
	For the Quarter Ended September 30, 2002

Commission File Number 0-21481

TRANSKARYOTIC THERAPIES, INC.
(Exact name of registrant as specified in its charter)

Delaware (State or other jurisdiction of incorporation or organization)	04-3027191 (I.R.S. Employer Identification No.)
700 Main Street Cambridge, Massachusetts (Address of principal executive offices)	02139 (Zip Code)
Registrant’s telephone number, including area code: (617) 349-0200

        Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.
                                                                                                Yes ý    No o

        At October 31, 2002, there were 34,842,922 shares of Common Stock, $.01 par value, outstanding.

Explanatory Note

        We are filing this amendment no. 1 to our Quarterly Report on Form 10-Q for the period ended September 30, 2002 on this Form 10-Q/A solely to refile Exhibit 10.32.

SIGNATURES

        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 thereunto duly authorized.

	TRANSKARYOTIC THERAPIES, INC.
Date: April 3, 2003	By:	/s/ Daniel E. Geffken
		Daniel E. Geffken
		Senior Vice President, Finance and
		Chief Financial Officer (Principal
		Financial and Accounting Officer)

CERTIFICATIONS

        I, Michael J. Astrue, certify that:

        (1) I have reviewed this quarterly report on Form 10-Q/A of Transkaryotic Therapies, Inc.; and

        (2) Based on my knowledge, this quarterly report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this quarterly report.

Dated: April 3, 2003
	/s/ Michael J. Astrue
	Michael J. Astrue
	President and Chief Executive
	Officer

        I, Daniel E. Geffken, certify that:

        (1) I have reviewed this quarterly report on Form 10-Q/A of Transkaryotic Therapies, Inc.; and

        (2) Based on my knowledge, this quarterly report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this quarterly report.

Dated: April 3, 2003
	/s/ Daniel E. Geffken
	Daniel E. Geffken
	Senior Vice President, Finance and
	Chief Financial Officer

EXHIBIT INDEX

10.32# Commercial Supply and Process Validation Agreement, entered into as of December 6, 1999, by and between TKT and Chesapeake Biological Laboratories, Inc.

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Confidential treatment requested as to certain portions pursuant to Rule 24-b-2 promulgated under the Exchange Act of 1934, as amended.