Sec Form 4 Filing - Thompson Peter A. @ ProNAi Therapeutics Inc - 2015-07-21

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

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1. Name and Address of Reporting Person Thompson Peter A. 2. Issuer Name and Ticker or Trading Symbol ProNAi Therapeutics Inc [ DNAI] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O PRONAI THERAPEUTICS, INC., 2150 ? 885 WEST GEORGIA ST. 3. Date of Earliest Transaction (MM/DD/YY) 07/21/2015 (Street) VANCOUVER, A1V6C 3E8 4. If Amendment, Date Original Filed (MM/DD/YY) 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 (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 07/21/2015 C 1,725,790 A 1,725,790 I See Footnotes ( 2 ) ( 3 ) Common Stock 07/21/2015 J( 4 ) 89,159 A $ 5.215 1,814,949 I See Footnotes ( 2 ) ( 3 ) Common Stock 07/21/2015 P 175,000 A $ 17 1,989,949 I See Footnotes ( 2 ) ( 3 )

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 Series D Preferred Stock ( 1 ) 07/21/2015 C 1,725,790 ( 1 ) ( 1 ) Common Stock 1,725,790 $ 0 0 I See Footnotes ( 2 ) ( 3 )

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Thompson Peter A. C/O PRONAI THERAPEUTICS, INC. 2150 ? 885 WEST GEORGIA ST. VANCOUVER, A1V6C 3E8 X Signatures /s/ Sukhi Jagpal as attorney-in-fact for Peter Thompson, M.D. 07/21/2015 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Each share of the issuer's Series D Preferred Stock automatically converted into 1 share of the issuer's Common Stock on July 21, 2015 in connection with the closing of the issuer's sale of its Common Stock in its firm commitment initial public offering pursuant to a registration statement on Form S-1 (File No. 333-204921) under the Securities Act of 1933, as amended, and had no expiration date. ( 2 )These securities are held of record by OrbiMed Private Investments V, LP ("OPI V"). OrbiMed Capital GP V LLC ("GP V") is the sole general partner of OPI V, and OrbiMed Advisors LLC ("Advisors") is the managing member of GP V. Samuel D. Isaly ("Isaly"), a natural person, is the managing member of and owner of a controlling interest in Advisors. By virtue of such relationships, GP V, Advisors and Isaly may be deemed to have voting and investment power over the securities held by OPI V and as a result may be deemed to have beneficial ownership over such securities. The Reporting Person is an employee of Advisors. ( 3 )Each of GP V, Advisors, Isaly and the Reporting Person disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of its or his pecuniary interest therein, if any. This report on Form 4 shall not be deemed an admission that any such entity or person, including the Reporting Person, is a beneficial owner of such securities for the purpose of Section 16 of the Exchange Act, or for any other purpose. ( 4 )Represents shares of Common Stock issued by the issuer in payment of cumulative accrued dividends.

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).

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