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* Longitude Capital Partners IV, LLC (Last) (First) (Middle) 2740 SAND HILL ROAD 2ND FLOOR (Street) MENLO PARK CA 94025 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 11/02/2023	3. Issuer Name and Ticker or Trading Symbol Lexeo Therapeutics, Inc. [ LXEO ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) 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) Form filed by One Reporting Person X 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)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Series A convertible preferred stock	(1)	(1)	Common Stock	1,793,429	(1)	I	By Longitude Venture Partners IV, L.P.(2)
Series B convertible preferred stock	(3)	(3)	Common Stock	274,314(3)	(3)	I	By Longitude Venture Partners IV, L.P.(2)

1. Name and Address of Reporting Person* Longitude Capital Partners IV, LLC (Last) (First) (Middle) 2740 SAND HILL ROAD 2ND FLOOR (Street) MENLO PARK CA 94025 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Longitude Venture Partners IV, L.P. (Last) (First) (Middle) 2740 SAND HILL ROAD 2ND FLOOR (Street) MENLO PARK CA (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Tammenoms Bakker Juliet (Last) (First) (Middle) C/O LONGITUDE CAPITAL 2740 SAND HILL ROAD, 2ND FLOOR (Street) MENLO PARK CA 94025 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* ENRIGHT PATRICK G (Last) (First) (Middle) C/O LONGITUDE CAPITAL 2740 SAND HILL ROAD, 2ND FLOOR (Street) MENLO PARK CA 94025 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

Explanation of Responses:

1. Each share of Series A convertible preferred stock is convertible into Common Stock on a 1-for-10.594230 basis at any time at the Reporting Person's election, and automatically upon the closing of the Issuer's initial public offering without payment or further consideration. The shares have no expiration date.

2. These shares are held by Longitude Venture Partners IV, L.P ("LVP IV"). Longitude Capital Partners IV, LLC ("LCP IV") is the general partner of LVP IV and may be deemed to have voting and dispositive power over the shares held by LVP IV. Mr. Enright and Ms. Tammenoms Bakker are managing members of LCP IV and may be deemed to share voting and dispositive power with respect to the shares held by LVP IV. Each of LCP IV, Mr. Enright and Ms. Tammenoms Bakker disclaims beneficial ownership of such shares and this report shall not be deemed an admission that any of them is the beneficial owner of such securities for purposes of Section 16 or for any other purpose, except to the extent of their respective pecuniary interests therein.

3. Each share of Series B convertible preferred stock is convertible into Common Stock on a 1-for-10.594230 basis at any time at the Reporting Person's election, and automatically upon the closing of the Issuer's initial public offering without payment or further consideration. Excludes shares of Common Stock issuable upon the closing of the Issuer's initial public offering pursuant to anti-dilution adjustment provisions of the Series B convertible preferred stock. The shares have no expiration date.

Remarks:

	Longitude Capital Partners IV, LLC By: /s/ Cristiana Blauth Oliveira , Authorized Signatory	11/02/2023
	Longitude Venture Partners IV, L.P. By: /s/ Cristiana Blauth Oliveira , Authorized Signatory of the General Partner	11/02/2023
	/s/ Cristiana Blauth Oliveira , Attorney-in-Fact for Juliet Tammenoms Bakker	11/02/2023
	/s/ Cristiana Blauth Oliveira, Attorney-in-Fact for Patrick Enright	11/02/2023
	** Signature of Reporting Person	Date
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