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^*

Reardon Tighe

(Last)

(First)

(Middle)

C/O SYNTHORX, INC.

11099 N. TORREY PINES ROAD, SUITE 190

(Street)

LA JOLLA

92037

(City)

(State)

(Zip)

2. Date of Event Requiring Statement (Month/Day/Year)
12/06/2018

3. Issuer Name and Ticker or Trading Symbol
Synthorx, Inc. [ THOR ]

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

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

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)
Common Stock	43,688	D

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)
Employee Stock Option (right to buy)	⁽¹⁾	08/29/2028	Common Stock	18,723	$4.64	D
Series C Preferred Stock	⁽²⁾	⁽²⁾	Common Stock	1,136,631⁽³⁾	⁽²⁾	I	By Avalon X SPV, L.P.⁽⁴⁾

Explanation of Responses:

1. Immediately exercisable.

2. The shares of Series C Preferred Stock have no expiration date and are convertible at any time at the election of the holder into shares of Common Stock without payment of further consideration. Each share of Series C Preferred Stock will automatically convert on a 1.60224-to-1 basis into shares of Common Stock upon the closing of the Issuer's initial public offering.

3. Share numbers give effect to the 1.60224-to-1 reverse stock split of the Issuer's Common Stock effected on November 26, 2018, which will be effective for the Preferred Stock upon its conversion to Common Stock upon the closing of the Issuer's initial public offering.

4. The Reporting Person is Chief Financial Officer and Partner of Avalon X SPV GP, general partner of Avalon X SPV, L.P., and shares voting and investment power with respect to the shares held by Avalon X SPV, L.P. The Reporting Person disclaims beneficial ownership of the shares held by Avalon X SPV, L.P., except to the extent of his actual pecuniary interest therein if any.

Remarks:

	/s/ Christian V. Kuhlen, Attorney-in-Fact	12/06/2018
	** 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).
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.