Sec Form 4 Filing - INSIGHT VENTURE PARTNERS IV LP @ Medidata Solutions, Inc. - 2009-12-14

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 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

OMB APPROVAL OMB Number: 3235-0287 Expires: November 30, 2011 Estimated average burden hours per response... 0.5

1. Name and Address of Reporting Person INSIGHT VENTURE PARTNERS IV LP 2. Issuer Name and Ticker or Trading Symbol Medidata Solutions, Inc. [ MDSO] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 680 FIFTH AVENUE - 8TH FLOOR 3. Date of Earliest Transaction (MM/DD/YY) 12/14/2009 (Street) NEW YORK, NY10019 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) _____ Form filed by One Reporting Person __ X __ 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 (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 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 12/14/2009 S 2,341,778 D $ 14.175 ( 7 ) 1,456,909 D ( 1 ) Common Stock 12/14/2009 S 313,816 D $ 14.175 ( 7 ) 194,038 D ( 2 ) Common Stock 12/14/2009 S 287,171 D $ 14.175 ( 7 ) 180,974 D ( 3 ) Common Stock 12/14/2009 S 17,763 D $ 14.175 ( 7 ) 12,422 D ( 4 ) Common Stock 12/14/2009 S 2,960,528 D $ 14.175 ( 7 ) 1,844,343 I ( 5 ) ( 6 ) See Footnotes (5) and (6)

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 (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 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 (MM/DD/YY) 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

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other INSIGHT VENTURE PARTNERS IV LP 680 FIFTH AVENUE - 8TH FLOOR NEW YORK, NY10019 X Insight Venture Partners IV (Co-Investors), L.P. 680 FIFTH AVENUE, 8TH FLOOR NEW YORK, NY10019 X Insight Venture Partners IV (Cayman), L.P. 680 FIFTH AVENUE, 8TH FLOOR NEW YORK, NY10019 X Insight Venture Partners IV (Fund B), L.P. 680 FIFTH AVENUE, 8TH FLOOR NEW YORK, NY10019 X Insight Venture Associates IV, LLC 680 FIFTH AVENUE, 8TH FLOOR NEW YORK, NY10019 X Insight Holdings Group, LLC 680 FIFTH AVENUE, 8TH FLOOR NEW YORK, NY10019 X Signatures See Signatures attached as Exhibit 99.1 12/14/2009 Signature of Reporting Person Date

Explanation of Responses:

( 1 )The amount listed reflects the beneficial ownership of the Issuer's securities owned by Insight Venture Partners IV, L.P. ("IVP IV"), all of which may be deemed attributable to Insight Venture Associates IV, L.L.C. (the "Insight GP"), because the Insight GP is the sole general partner of IVP IV. ( 2 )The amount listed reflects the beneficial ownership of the Issuer's securities owned by Insight Venture Parters (Cayman) IV, L.P. ("IVP IV Cayman"), all of which may be deemed attributable to the Insight GP because the Insight GP is the sole general partner of IVP IV Cayman. ( 3 )The amount listed reflects the beneficial ownership of the Issuer's securities owned by Insight Venture Parters IV ("Co-Investors"), L.P. ("IVP IV CO"), all of which may be deemed attributable to the Insight GP because the Insight GP is the sole general partner of IVP IV CO. ( 4 )The amount listed reflects the beneficial ownership of the Issuer's securities owned by Insight Venture Partners IV (Fund B), L.P. ("IVP Fund B" together with IVP IV, IVP IV CO and IVP IV Cayman, the "Insight Funs"), all of which may be deemed attributable to the Insight GP because the Insight GP is the sole general partner of IVP Fund B. ( 5 )The amount listed reflects the beneficial ownership of the Issuer's securities owned by the Insight Funds, all of which may be deemed attributable to the Insight GP because the Insight GP is the sole general partner of each of the Insight Funds. ( 6 )The amount listed reflects the beneficial ownership of the Issuer's securities owned by the Insight Funds and the Insight GP, all of which may be deemed attributable to Insight Holdings Group, L.L.C. ("Holdings") because Holdings is the managing member of the Insight GP. ( 7 )Represents public offering price of $15.00 per share less the underwriter's discount of $0.825 per share.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* 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).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.