SEC Filing - Parabilis Medicines

SCHEDULE 13G

CUSIP No.

Names of Reporting Persons

ARCH Venture Fund XII, L.P.

Check the appropriate box if a member of a Group (see instructions)

(a)

(b)

Sec Use Only

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 6,412,780.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 6,412,780.00

Aggregate Amount Beneficially Owned by Each Reporting Person

6,412,780.00

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

Checkbox not checked

Percent of class represented by amount in row (9)

5.3 %

Type of Reporting Person (See Instructions)

SCHEDULE 13G

CUSIP No.

Names of Reporting Persons

ARCH Venture Partners XII, L.P.

Check the appropriate box if a member of a Group (see instructions)

(a)

(b)

Sec Use Only

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 6,412,780.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 6,412,780.00

Aggregate Amount Beneficially Owned by Each Reporting Person

6,412,780.00

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

Checkbox not checked

Percent of class represented by amount in row (9)

5.3 %

Type of Reporting Person (See Instructions)

SCHEDULE 13G

CUSIP No.

Names of Reporting Persons

ARCH Venture Partners XII, LLC

Check the appropriate box if a member of a Group (see instructions)

(a)

(b)

Sec Use Only

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 6,412,780.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 6,412,780.00

Aggregate Amount Beneficially Owned by Each Reporting Person

6,412,780.00

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

Checkbox not checked

Percent of class represented by amount in row (9)

5.3 %

Type of Reporting Person (See Instructions)

SCHEDULE 13G

CUSIP No.

Names of Reporting Persons

Robert Nelsen

Check the appropriate box if a member of a Group (see instructions)

(a)

(b)

Sec Use Only

Citizenship or Place of Organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 6,412,780.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 6,412,780.00

Aggregate Amount Beneficially Owned by Each Reporting Person

6,412,780.00

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

Checkbox not checked

Percent of class represented by amount in row (9)

5.3 %

Type of Reporting Person (See Instructions)

SCHEDULE 13G

CUSIP No.

Names of Reporting Persons

Keith Crandell

Check the appropriate box if a member of a Group (see instructions)

(a)

(b)

Sec Use Only

Citizenship or Place of Organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 6,412,780.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 6,412,780.00

Aggregate Amount Beneficially Owned by Each Reporting Person

6,412,780.00

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

Checkbox not checked

Percent of class represented by amount in row (9)

5.3 %

Type of Reporting Person (See Instructions)

SCHEDULE 13G

CUSIP No.

Names of Reporting Persons

Kristina Burow

Check the appropriate box if a member of a Group (see instructions)

(a)

(b)

Sec Use Only

Citizenship or Place of Organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 6,412,780.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 6,412,780.00

Aggregate Amount Beneficially Owned by Each Reporting Person

6,412,780.00

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

Checkbox not checked

Percent of class represented by amount in row (9)

5.3 %

Type of Reporting Person (See Instructions)

SCHEDULE 13G

CUSIP No.

Names of Reporting Persons

Steven Gillis

Check the appropriate box if a member of a Group (see instructions)

(a)

(b)

Sec Use Only

Citizenship or Place of Organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 6,412,780.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 6,412,780.00

Aggregate Amount Beneficially Owned by Each Reporting Person

6,412,780.00

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

Checkbox not checked

Percent of class represented by amount in row (9)

5.3 %

Type of Reporting Person (See Instructions)

SCHEDULE 13G

Item 1.

(a)

Name of issuer:

Parabilis Medicines, Inc.

(b)

Address of issuer's principal executive offices:

30 Acorn Park Drive, Cambridge, MA 02140

Item 2.

(a)

Name of person filing:

ARCH Venture Fund XII, L.P. ("AVF XII"); ARCH Venture Partners XII, L.P. ("AVP XII LP"); ARCH Venture Partners XII, LLC ("AVP XII LLC") (collectively, the "Reporting Entities" and individually, each a "Reporting Entity"); and Keith Crandell ("Crandell"), Robert Nelsen ("Nelsen"), Kristina Burow ("Burow") and Steven Gillis ("Gillis") (collectively, the "Investment Committee" and individually, each a "Committee Member"). The Reporting Entities and the Committee Members collectively are referred to as the "Reporting Persons." The Reporting Persons are filing this report with respect to shares of Common Stock, par value $0.0001 per share (the "Common Stock") of Parabilis Medicines, Inc. (the "Issuer").

(b)

Address or principal business office or, if none, residence:

The business address of each of the Reporting Persons is 8755 West Higgins Road, Suite 1025, Chicago, IL, 60631.

(c)

Citizenship:

AVF XII and AVP XII LP are limited partnerships organized under the laws of the State of Delaware. AVP XII LLC is a limited liability company organized under the laws of the State of Delaware. Each Committee Member is a US citizen.

(d)

Title of class of securities:

Common Stock, $0.0001 par value

(e)

CUSIP No.:

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);

(b)

Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);

(c)

Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);

(d)

Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);

(e)

An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);

(f)

An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);

(g)

A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);

(h)

A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);

(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);

(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:

(k)

Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).

Item 4.

Ownership

(a)

Amount beneficially owned:

AVF XII is the record owner of 6,412,780 shares of Common Stock (the "Record Shares") as of June 30, 2026. AVP XII LP, as the sole general partner of AVF XII, may be deemed to beneficially own the Record Shares. AVP XII LLC, as the sole general partner of AVP XII, may be deemed to beneficially own the Record Shares. As Committee Members of AVP XII LLC, each Committee Member may also be deemed to share the power to direct the disposition and vote of the Record Shares. Each Reporting Person disclaims beneficial ownership of such shares of Common Stock except for the shares, if any, such Reporting Person holds of record.

(b)

Percent of class:

The information required by Item 4(b) is incorporated by reference to Row 11 of the cover pages hereto. The percentages set forth on the cover sheet for each Reporting Person are based upon 121,952,030 shares of Common Stock outstanding as of August 10, 2026, as reported by the Issuer in its Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on August 13, 2026. %

(c)

Number of shares as to which the person has:

(i) Sole power to vote or to direct the vote:

See row 5 of the cover pages.

(ii) Shared power to vote or to direct the vote:

See row 6 of the cover pages.

(iii) Sole power to dispose or to direct the disposition of:

See row 7 of the cover pages.

(iv) Shared power to dispose or to direct the disposition of:

See row 8 of the cover pages.

Item 5.

Ownership of 5 Percent or Less of a Class.

Item 6.

Ownership of more than 5 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.

Certifications:

Not Applicable

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

ARCH Venture Fund XII, L.P.

Signature:	ARCH Venture Partners XII, L.P.
Name/Title:	its General Partner
Date:	08/14/2026

Signature:	ARCH Venture Partners XII, LLC
Name/Title:	its General Partner
Date:	08/14/2026

Signature:	/s/ Mark McDonnell*
Name/Title:	Mark McDonnell, as Attorney-in-Fact for Keith Crandell, Managing Director
Date:	08/14/2026

ARCH Venture Partners XII, L.P.

Signature:	ARCH Venture Partners XII, LLC
Name/Title:	its General Partner
Date:	08/14/2026

Signature:	/s/ Mark McDonnell*
Name/Title:	Mark McDonnell, as Attorney-in-Fact for Keith Crandell, Managing Director
Date:	08/14/2026

ARCH Venture Partners XII, LLC

Signature:	/s/ Mark McDonnell*
Name/Title:	Mark McDonnell, as Attorney-in-Fact for Keith Crandell, Managing Director
Date:	08/14/2026

Robert Nelsen

Signature:	/s/ Mark McDonnell*
Name/Title:	Mark McDonnell, as Attorney-in-Fact for Robert Nelsen
Date:	08/14/2026

Keith Crandell

Signature:	/s/ Mark McDonnell*
Name/Title:	Mark McDonnell, as Attorney-in-Fact for Keith Crandell
Date:	08/14/2026

Kristina Burow

Signature:	/s/ Mark McDonnell*
Name/Title:	Mark McDonnell, as Attorney-in-Fact for Kristina Burow
Date:	08/14/2026

Steven Gillis

Signature:	/s/ Mark McDonnell*
Name/Title:	Mark McDonnell, as Attorney-in-Fact for Steven Gillis
Date:	08/14/2026

Comments accompanying signature: This Schedule 13G was executed by Mark McDonnell pursuant to a Power of Attorney filed as Exhibit 24 to the Form 3 relating to the beneficial ownership of shares of Neumora Therapeutics, Inc. by the Reporting Persons filed with the Securities and Exchange Commission on September 14, 2023 and incorporated herein in its entirety by reference.

Exhibit Information

Exhibit 1 - Joint Filing Agreement