SEC FORM 3

SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person^*

ENRIGHT PATRICK G

(Last)

(First)

(Middle)

C/O LONGITUDE CAPITAL PARTNERS II, LLC

2740 SAND HILL RD 2ND FLOOR

(Street)

MENLO PARK

94025

(City)

(State)

(Zip)

2. Date of Event Requiring Statement (Month/Day/Year)
06/20/2018

3. Issuer Name and Ticker or Trading Symbol
Aptinyx Inc. [ APTX ]

4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

5. If Amendment, Date of 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

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
1. Title of Derivative Security (Instr. 4)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
Series A-1 Convertible Preferred Stock	⁽¹⁾	⁽¹⁾	Common Stock	1,047,450	⁽¹⁾	I	See footnote⁽²⁾
Series A-2 Convertible Preferred Stock	⁽¹⁾	⁽¹⁾	Common Stock	1,197,076	⁽¹⁾	I	See footnote⁽²⁾
Series B Convertible Preferred Stock	⁽¹⁾	⁽¹⁾	Common Stock	795,553	⁽¹⁾	I	See footnote⁽²⁾

Explanation of Responses:

1. All series of convertible preferred stock will automatically convert into the number of shares of the Issuer's common stock on a 27.58621-for-1 basis immediately prior to the closing of the Issuer's initial public offering and have no expiration date.

2. The shares are held by Longitude Venture Partners II, L.P. ("Longitude Venture II"). Longitude Capital Partners II, LLC ("Longitude Capital II") is the general partner of Longitude Venture II and may be deemed to have shared voting, investment and dispositive power over the shares held by Longitude Venture II. Patrick G. Enright is a managing member of Longitude Capital II and in his capacity as such may be deemed to exercise shared voting and investment power over the shares held by Longitude Venture II. Mr. Enright disclaims beneficial ownership of such shares except to the extent of his pecuniary interest therein.

	/s/ Patrick G. Enright	06/20/2018
	** Signature of Reporting Person	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 5 (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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