FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person * Tessmer James F   2. Issuer Name and Ticker or Trading Symbol LEXICON PHARMACEUTICALS, INC./DE [LXRX] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) VP, Finance & Accounting (Last) (First) (Middle) 8800 TECHNOLOGY FOREST PLACE 3. Date of Earliest Transaction (Month/Day/Year) 02/12/2010 (Street) THE WOODLANDS, TX 77381 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 02/12/2010   F(1)   3,934 D $ 1.91 18,679 D

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Stock Option (Right to Buy)

$ 1.9

02/15/2010

A

100,000

(2)

02/15/2020

Common Stock

100,000

$ 0

100,000

D

Restricted Stock Units (Phantom Stock)

(3)

02/15/2010

A

13,200

(4)

(4)

Common Stock

13,200

$ 0

13,200

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Tessmer James F 8800 TECHNOLOGY FOREST PLACE THE WOODLANDS, TX 77381			VP, Finance & Accounting

Signatures

/s/ James F. Tessmer		02/17/2010
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	Withholding of a portion of vested shares by the Company in satisfaction of shareholder's tax withholding obligations with respect thereto.
(2)	Option vests with respect to 25% of the shares subject to the option on the first anniversary of grant (2/15/2011) and vests 1/48th per month for each month of service thereafter.
(3)	Each restricted stock unit represents a contingent right to receive one share of common stock.
(4)	Restricted stock units vest with respect to 100% of the shares subject to the restricted stock unit upon the dosing of the first patient in a pivotal human clinical trial in any country, the results of which could be used to establish safety and efficacy of a pharmaceutical product discovered or developed by the Company (whether or not licensed by the Company to a third party) as a basis for a New Drug Application with the U.S. Food and Drug Administration or that would otherwise satisfy the requirements of 21 CFR 321.21(c) or its foreign equivalent.

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