Newpath Partners SC 13G Prime Medicine / Newpath Partners ownership change

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

SCHEDULE 13G

Under the Securities Exchange Act of 1934

(Amendment No.    )*

Prime Medicine, Inc.

(Name of Issuer)

Common Stock, par value $0.00001 per share

(Title of Class of Securities)

74168J101

(CUSIP Number)

December 31, 2022

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

☐ Rule 13d-1(b)

☐ Rule 13d-1(c)

☒ Rule 13d-1(d)

* The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

CUSIP No. 74168J101

1	NAMES OF REPORTING PERSONS   I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)   Newpath Partners, L.P.
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)   (a)  ☐        (b)  ☐
3	SEC USE ONLY
4	CITIZENSHIP OR PLACE OF ORGANIZATION   Delaware

NUMBER OF SHARES  BENEFICIALLY  OWNED BY EACH REPORTING PERSON WITH:	5	SOLE VOTING POWER   0
	6	SHARED VOTING POWER   5,305,679
	7	SOLE DISPOSITIVE POWER   0
	8	SHARED DISPOSITIVE POWER   5,305,679

9	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON   5,305,679
10	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS)   ☐
11	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9   5.5%
12	TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)   PN

CUSIP No. 74168J101

1	NAMES OF REPORTING PERSONS   I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)   Newpath Partners GP, L.P.
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)   (a)  ☐        (b)  ☐
3	SEC USE ONLY
4	CITIZENSHIP OR PLACE OF ORGANIZATION   Delaware

NUMBER OF SHARES  BENEFICIALLY  OWNED BY EACH REPORTING PERSON WITH:	5	SOLE VOTING POWER   0
	6	SHARED VOTING POWER   5,305,679
	7	SOLE DISPOSITIVE POWER   0
	8	SHARED DISPOSITIVE POWER   5,305,679

9	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON   5,305,679
10	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS)   ☐
11	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9   5.5%
12	TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)   PN

CUSIP No. 74168J101

1	NAMES OF REPORTING PERSONS   I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)   Newpath Partners GP, LLC
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)   (a)  ☐        (b)  ☐
3	SEC USE ONLY
4	CITIZENSHIP OR PLACE OF ORGANIZATION   Delaware

NUMBER OF SHARES  BENEFICIALLY  OWNED BY EACH REPORTING PERSON WITH:	5	SOLE VOTING POWER   0
	6	SHARED VOTING POWER   5,305,679
	7	SOLE DISPOSITIVE POWER   0
	8	SHARED DISPOSITIVE POWER   5,305,679

9	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON   5,305,679
10	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS)   ☐
11	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9   5.5%
12	TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)   OO

CUSIP No. 74168J101

1	NAMES OF REPORTING PERSONS   I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)   Thomas Cahill
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS)   (a)  ☐        (b)  ☐
3	SEC USE ONLY
4	CITIZENSHIP OR PLACE OF ORGANIZATION   United States of America

NUMBER OF SHARES  BENEFICIALLY  OWNED BY EACH REPORTING PERSON WITH:	5	SOLE VOTING POWER   0
	6	SHARED VOTING POWER   5,305,679
	7	SOLE DISPOSITIVE POWER   0
	8	SHARED DISPOSITIVE POWER   5,305,679

9	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON   5,305,679
10	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS)   ☐
11	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9   5.5%
12	TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)   IN

Item 1(a). Name of Issuer:

Prime Medicine, Inc. (the “Issuer”)

Item 1(b). Address of Issuer’s Principal Executive Offices:

21 Erie Street

Cambridge, MA 02139

Item 2(a). Names of Persons Filing:

The names of the persons filing this report (collectively, the “Reporting Persons”) are:

Newpath Partners, L.P. (“Newpath LP”);

Newpath GP, L.P. (“Newpath GP LP”);

Newpath GP, LLC (“Newpath GP LLC”); and

Thomas Cahill (“Mr. Cahill”)

Item 2(b). Address of Principal Business Office or, if None, Residence:

The address of the principal business office of each of the Reporting Persons is:

800 Boylston Street, Suite 2222

Boston, MA 02199

Item 2(c). Citizenship:

Newpath LP is a Delaware limited partnership;

Newpath GP LP is a Delaware limited partnership;

Newpath GP LLC is a Delaware limited liability company; and

Mr. Cahill is a United States citizen

Item 2(d). Title of Class of Securities:

Common Stock, par value $0.00001 per share (“Common Stock”)

Item 2(e). CUSIP Number:

74168J101

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:

Not applicable.

Item 4. Ownership.

The information required by this item with respect to each Reporting Person is set forth in Rows 5 through 9 and 11 of the cover pages to this Schedule 13G. The ownership

percentages reported are based on 97,208,342 shares of Common Stock outstanding as of November 8, 2022, as reported in the Issuer’s quarterly report on Form 10-Q filed with the Securities and Exchange Commission on November 14, 2022.

Newpath LP directly holds 5,305,679 shares of the Issuer’s Common Stock. Newpath GP LP is the general partner of Newpath LP and Newpath GP LLC is the general partner of Newpath GP LP. Thomas Cahill, a member of the Issuer’s board of directors, is the managing member of Newpath GP LLC.

Item 5. Ownership of Five Percent or Less of a Class.

If this statement is being filed to report the fact that as of the date hereof the Reporting Persons have ceased to be the beneficial owner of more than five percent of the class of securities, check the following ☐.

Item 6. Ownership of More than Five Percent on Behalf of Another Person.

Not applicable.

Item 7. Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.

Not applicable.

Item 8. Identification and Classification of Members of the Group.

Not applicable.

Item 9. Notice of Dissolution of Group.

Not applicable.

Item 10. Certification.

Not applicable.

SIGNATURE

After reasonable inquiry and to the best of its knowledge and belief, each of the undersigned certifies that the information set forth in this statement is true, complete and correct.

Date:	February 7, 2023
NEWPATH PARTNERS, L.P.
By:	/s/ Newpath Partners GP, L.P.
By:	/s/ Thomas Cahill
	By: Thomas Cahill
	Title: Managing Member
NEWPATH PARTNERS GP, L.P.
By:	/s/ Newpath Partners GP, LLC
By:	/s/ Thomas Cahill
	By: Thomas Cahill
	Title: Managing Member
NEWPATH PARTNERS GP, LLC
By:	/s/ Thomas Cahill
	By: Thomas Cahill
	Title: Managing Member

By:	/s/ Thomas Cahill
THOMAS CAHILL