| Item 1. | |
| (a) | Name of issuer:
Odyssey Therapeutics, Inc. |
| (b) | Address of issuer's principal executive offices:
51 Sleeper Street, Suite 800, Boston, MA, 02210 . |
| Item 2. | |
| (a) | Name of person filing:
The names of the persons filing this report (collectively, the "Reporting Persons") are:
Lightspeed Venture Partners XV-B (Ignite), L.P. ("Lightspeed XV-B")
Lightspeed General Partner XV-B (Ignite), L.P. ("LGP XV-B")
Lightspeed Ultimate General Partner XV-B (Ignite), L.L.C. ("LUGP XV-B")
The Reporting Persons expressly disclaim status as a "group" for purposes of this Schedule 13G. |
| (b) | Address or principal business office or, if none, residence:
c/o Lightspeed Venture Partners
2200 Sand Hill Road
Menlo Park, CA 94025 |
| (c) | Citizenship:
Lightspeed XV-B Delaware
LGP XV-B Delaware
LUGP XV-B Delaware
|
| (d) | Title of class of securities:
Common Stock, $0.0001 par value per share |
| (e) | CUSIP No.:
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| Item 3. | If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a: |
| (a) |  Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
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| (b) | Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
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| (c) | Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
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| (d) | Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
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| (e) | An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
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| (f) | An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
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| (g) | A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
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| (h) | A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
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| (i) | A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
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| (j) | A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J),
please specify the type of institution:
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| (k) | Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
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| | |
| Item 4. | Ownership |
| (a) | Amount beneficially owned:
Row 9 of each Reporting Person's cover page to this Schedule 13G sets forth the aggregate number of shares of common stock of the Issuer beneficially owned by such Reporting Person and is incorporated by reference.
The Reporting Persons' ownership of the Issuer's securities consists of 3,608,443 shares of common stock directly held by Lightspeed XV-B.
LUGP XV-B serves as the sole general partner of LGP XV-B, which serves as the sole general partner of Lightspeed XV-B.
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| (b) | Percent of class:
Row 11 of each Reporting Person's cover page to this Schedule 13G sets forth the percentages of the shares of common stock of the Issuer beneficially owned by such Reporting Person and is incorporated by reference. The percentage set forth in each row 11 is based upon 47,174,156 shares of common stock outstanding as of May 11, 2026, as reported in the Issuer's prospectus dated May 7, 2026 filed with the Securities and Exchange Commission (the "SEC") on May 8, 2026. |
| (c) | Number of shares as to which the person has:
|
| | (i) Sole power to vote or to direct the vote:
Row 5 of each Reporting Person's cover page to this Schedule 13G sets forth the sole power to vote or to direct the vote of securities of the Issuer beneficially owned by such Reporting Person and is incorporated by reference.
|
| | (ii) Shared power to vote or to direct the vote:
Row 6 of each Reporting Person's cover page to this Schedule 13G sets forth the shared power to vote or to direct the vote of securities of the Issuer beneficially owned by such Reporting Person and is incorporated by reference.
|
| | (iii) Sole power to dispose or to direct the disposition of:
Row 7 of each Reporting Person's cover page to this Schedule 13G sets forth the sole power to dispose or to direct the disposition of securities of the Issuer beneficially owned by such Reporting Person and is incorporated by reference.
|
| | (iv) Shared power to dispose or to direct the disposition of:
Row 8 of each Reporting Person's cover page to this Schedule 13G sets forth the shared power to dispose or to direct the disposition of securities of the Issuer beneficially owned by such Reporting Person and is incorporated by reference.
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| Item 5. | Ownership of 5 Percent or Less of a Class. |
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Not Applicable
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| Item 6. | Ownership of more than 5 Percent on Behalf of Another Person. |
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Not Applicable
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| Item 7. | Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person. |
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Not Applicable
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| Item 8. | Identification and Classification of Members of the Group. |
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Not Applicable
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| Item 9. | Notice of Dissolution of Group. |
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Not Applicable
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Rule 13d-1(c)