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 * Krasnow Lineene Norris   2. Issuer Name and Ticker or Trading Symbol Medidata Solutions, Inc. [MDSO] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) EVP - Product and Marketing (Last) (First) (Middle) C/O MEDIDATA SOLUTIONS, INC., 79 FIFTH AVENUE, 8TH FLOOR 3. Date of Earliest Transaction (Month/Day/Year) 12/09/2009 (Street) NEW YORK, NY 10003 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 12/09/2009   M   75,000 A $ 0.62 88,021 D   Common Stock 12/09/2009   S   75,000 (1) D $ 14.175 (2) 13,021 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)

$ 0.62

12/09/2009

M

75,000

(3)

08/15/2015

Common Stock

75,000

$ 0

70,000

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Krasnow Lineene Norris C/O MEDIDATA SOLUTIONS, INC. 79 FIFTH AVENUE, 8TH FLOOR NEW YORK, NY 10003			EVP - Product and Marketing

Signatures

/s/ Michael I. Otner, Attorney-in-Fact		12/10/2009
**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)	These shares of the issuer's common stock were sold by the reporting person in a registered underwritten secondary offering pursuant to an underwriting agreement entered into on December 8, 2009. The reporting person's sale of the issuer's common stock was matchable under Section 16(b) of the Securities Exchange Act of 1934, to the extent of 700 shares, with the reporting person's purchase pursuant to a directed share program established by the underwriters of the issuer's initial public offering of 700 shares of the issuer's common stock at a price of $14.00 per share on June 24, 2009. The reporting person has agreed to pay to the issuer, upon settlement of the sale, $122.50, representing the full amount of the profit realized in connection with the short-swing transaction, less transaction costs.
(2)	Represents public offering price of $15.00 per common share less the underwriter's discount of $0.825 per common share.
(3)	These options are fully vested and exercisable.

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