Sec Form 3 Filing - David Nathaniel E @ Unity Biotechnology, Inc. - 2018-05-02

FORM 3 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 David Nathaniel E 2. Issuer Name and Ticker or Trading Symbol Unity Biotechnology, Inc. [ UBX] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) President (Last) (First) (Middle) C/O UNITY BIOTECHNOLOGY, INC., 3280 BAYSHORE BOULEVARD 3. Date of Earliest Transaction (MM/DD/YY) 05/02/2018 (Street) BRISBANE, CA94005 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 980,846 D

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 A-2 Preferred Stock ( 1 ) ( 1 ) ( 2 ) Common Stock 1,074,032 D Series B Preferred Stock ( 1 ) ( 1 ) ( 2 ) Common Stock 222,148 D Series C Preferred Stock ( 1 ) ( 1 ) ( 2 ) Common Stock 1,630 D Stock Option (Right to Buy) $ 3.43 ( 3 ) 09/26/2027 Common Stock 27,118 D Stock Option (Right to Buy) $ 3.43 ( 4 )( 5 ) 09/26/2027 Common Stock 83,474 D Series A-1 Warrant $ 0.65 ( 1 ) 12/31/2018 Common Stock 192,823 D Series A-2 Warrant $ 0.66 ( 1 ) 12/31/2018 Common Stock 190,226 D Series A-2 Warrant $ 0.66 ( 1 ) 12/31/2018 Common Stock 380,452 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other David Nathaniel E C/O UNITY BIOTECHNOLOGY, INC. 3280 BAYSHORE BOULEVARD BRISBANE, CA94005 X President Signatures /s/ Tamara L. Tompkins, Attorney-in-Fact for Nathaniel E. David 05/02/2018 Signature of Reporting Person Date

Explanation of Responses:

( 1 )The shares of the Issuer's Preferred Stock automatically convert into shares of the Issuer's Common Stock, for no additional consideration, on a 1:1 basis immediately prior to the consummation of the Issuer's initial public offering. ( 2 )The expiration date is not relevant to the conversion of these securities. ( 3 )The shares subject to the option will vest in full on December 31, 2018. ( 4 )1/3 of the shares underlying the option will be scheduled to vest upon i) the closing of a financing where the Issuer sells shares of its equity securities to institutional investors at a price per share of at least $36.88, ii) a change in control with aggregate proceeds payable to holders of the Issuer's common stock at a price per share of at least $36.88, or iii) the Issuer attains an average trading price after IPO of at least $36.88 as measured by a trailing 30 day volume-weighted average price (VWAP) (continued) ( 5 )2/3 of the shares underlying the option will vest upon i) the closing of a financing where the Company sells shares of its equity securities to institutional investors with a pre-money valuation of at least $2.5B, ii) a change in control with aggregate proceeds payable to holders of the Company's common stock at a valuation of the Company of at least $2.5B, or iii) the Company attains a market capitalization after IPO of at least $2.5B as measured by a trailing 30 day VWAP, in each case subject to the reporting person's continuing services to the Issuer through each applicable vesting date.

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).

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