Lexeo Therapeutics Inc

As filed with the Securities and Exchange Commission on April 9, 2024

Registration

No. 333-

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORMS-1

REGISTRATION STATEMENT

Under

The Securities Act of 1933

LEXEO THERAPEUTICS, INC.

(Exact name of Registrant as specified in its charter)

345 Park Avenue South, Floor 6

New York, New York,10010

Tel: (212)

547-9879

(Address, including zip code, and telephone number, including area code, of Registrant’s principal executive offices)

Chief Executive Officer

345 Park Avenue South, Floor 6

New York, New York,10010

(212)

547-9879

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies to:

Approximate date of commencement of proposed sale to the public:

As soon as practicable after the effective date of this Registration Statement.

If any of the securities being registered on this form are to be offered on a delayed or continuous basis pursuant to Rule 415 under

the

Securities Act of 1933, check the following box.

If this form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.

If this form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.

If this form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a

non-accelerated

filer, smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in

Rule 12b-2

of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act.

The Registrant hereby amends this Registration Statement on such date or dates as may be necessary to delay its effective date until the Registrant shall file a further amendment which specifically states that this Registration Statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933, as amended or until the Registration Statement shall become effective on such date as the Securities and Exchange Commission acting pursuant to said Section 8(a), may determine.

The information in this preliminary prospectus is not complete and may be changed. These securities may not be sold until the registration statement filed with the Securities and Exchange Commission is effective. This prospectus is not an offer to sell these securities, nor does it seek an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

6,974,248 Shares of Common Stock

This prospectus relates to the offer and resale from time to time of up to 6,974,248 shares (the “Shares”) of common stock, par value $0.0001 per share (“Common Stock”), of Lexeo Therapeutics, Inc., a Delaware corporation (the “Company”), by the selling stockholders identified in this prospectus, including their transferees, pledgees or donees or their respective successors (the “Selling Stockholders”). The Shares consist of (i) 6,278,905 shares which were issued and sold to the Selling Stockholders on March 13, 2024 (the “Closing Date”) in a private placement (the “Private Placement”) pursuant to a common stock purchase agreement among us and such Selling Stockholders dated March 11, 2024 (the “Purchase Agreement”) and (ii) 695,343 shares of Common Stock held by the Selling Stockholders as of March 11, 2024. Concurrently with the Purchase Agreement, we entered into a registration rights agreement (the “Registration Rights Agreement”) with the Selling Stockholders, and we are registering the Shares being offered hereunder pursuant to such registration rights agreement on behalf of the Selling Stockholders, to be offered and sold by them from time to time.

The Selling Stockholders may sell any, all or none of the securities and we do not know when or in what amount the Selling Stockholders may sell their securities hereunder following the date of this prospectus. The Selling Stockholders may sell the securities described in this prospectus in a number of different ways and at varying prices. We provide more information about how the Selling Stockholders may sell their securities in the section titled “Plan of Distribution” appearing elsewhere in this prospectus.

We will not receive any of the proceeds from the sale of the securities by the Selling Stockholders. We will pay the expenses associated with registering the sales by the Selling Stockholders other than any underwriting discounts and commissions, as described in more detail in the section titled “Use of Proceeds” appearing elsewhere in this prospectus.

Of the 6,974,248 shares of Common Stock that may be offered or sold by Selling Stockholders identified in this prospectus, 695,343 of those shares (the“Lock-Up Shares”) are subject to certain lock-up restrictions pursuant to contractual agreements further described in the section titled “Certain Relationships and Related Person Transactions” appearing elsewhere in this prospectus.

Our Common Stock is listed on The Nasdaq Global Market (“Nasdaq”) under the symbol “LXEO”. On April 8, 2024, the last quoted sale price for our Common Stock as reported on Nasdaq was $13.16 per share.

We are an “emerging growth company” and a “smaller reporting company” as defined under the federal securities laws, and, as such, may elect to comply with certain reduced public company reporting requirements for this prospectus and for future filings. See “Prospectus Summary—Implications of Being an Emerging Growth Company and a Smaller Reporting Company.”

Investing in our securities involves a high degree of risk. Before buying any securities, you should carefully read the discussion of the risks of investing in our securities in “Risk Factors” beginning on page 13 of this prospectus.

You should rely only on the information contained in this prospectus or any prospectus supplement or amendment hereto. We have not authorized anyone to provide you with different information.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

Prospectus dated , 2024