Parabilis Medicines (PBLS): ARCH Venture group discloses 6.4M-share, 5.3% ownership

Rhea-AI Filing Summary

Parabilis Medicines, Inc. has disclosed that ARCH Venture Fund XII, L.P. is the record holder of 6,412,780 shares of its Common Stock. Through a chain of general partners and an investment committee, ARCH Venture Partners XII, L.P., ARCH Venture Partners XII, LLC, and four committee members may be deemed to share voting and dispositive power over these shares.

The position represents 5.3% of the Common Stock class, based on 121,952,030 shares outstanding as of August 10, 2026. All reporting parties disclaim beneficial ownership beyond any shares they hold directly.

Key Figures

Shares beneficially owned: 6,412,780 shares Percent of class: 5.3% Shares outstanding: 121,952,030 shares +2 more

5 metrics

Shares beneficially owned 6,412,780 shares Record Shares of Common Stock held by ARCH Venture Fund XII as of June 30, 2026

Percent of class 5.3% Ownership percentage based on shares outstanding reported by the issuer

Shares outstanding 121,952,030 shares Common Stock outstanding as of August 10, 2026, per the issuer’s Form 10-Q

Shared voting power 6,412,780 shares Number of shares over which each reporting person has shared voting power

Shared dispositive power 6,412,780 shares Number of shares over which each reporting person has shared dispositive power

Key Terms

beneficially own, shared voting power, dispositive power, Schedule 13G, +1 more

5 terms

beneficially own financial

"may be deemed to beneficially own the Record Shares"

Beneficially own means having the economic rights and risks of a security—such as the right to receive dividends, sell the shares, or profit from price changes—whether or not your name appears on the official share register. Think of it like renting a car: you use it and reap the benefits even if the title lists someone else. Investors care because beneficial ownership determines who truly controls value, must be disclosed under securities rules, and can signal potential influence or trading activity that affects a stock’s price.

shared voting power financial

"Shared Voting Power 6,412,780.00"

Shared voting power occurs when two or more parties jointly have the right to vote or decide how a block of company shares is cast, like co-owners who must agree before moving a piece of furniture. Investors care because who controls voting rights affects board elections, major corporate decisions and takeover outcomes, and shared control can alter regulatory disclosures and the practical influence any holder has over a company’s direction and value.

dispositive power financial

"Shared Dispositive Power 6,412,780.00"

Dispositive power is the authority to decide the final outcome of an asset, legal claim, contract, or corporate action — in effect the power to dispose of or resolve something. For investors it matters because whoever holds that authority can determine who gets paid, who controls an asset or vote, and how risks and returns are allocated; think of it like holding the key that lets you lock in the winner or loser in a deal.

Schedule 13G regulatory

"form_type": "SCHEDULE 13G""

A Schedule 13G is a formal document that investors file with the government when they acquire a large ownership stake in a company, usually for investment purposes rather than control. It helps keep the public informed about who owns significant parts of a company's shares, which can influence how the company is managed and how investors make decisions. Filing this schedule is important for transparency and understanding the ownership landscape of publicly traded companies.

CUSIP Number financial

"CUSIP Number(s): 698955101"

A CUSIP number is a nine-character code that uniquely identifies a specific U.S. or Canadian stock, bond, or other security, similar to a barcode or a social-security number for a financial instrument. It matters to investors because it removes confusion between similar securities, ensures trades and settlements are applied to the correct issue, and helps locate official documents and transaction records quickly.

FAQ

What percentage of Parabilis Medicines (PBLS) does ARCH Venture Fund XII report owning?

ARCH Venture Fund XII and related entities report beneficial ownership of 5.3% of Parabilis Medicines’ Common Stock, based on 121,952,030 shares outstanding as of August 10, 2026, as stated in the company’s Form 10-Q.

How many Parabilis Medicines (PBLS) shares are held by ARCH Venture Fund XII?

ARCH Venture Fund XII is the record owner of 6,412,780 shares of Parabilis Medicines’ Common Stock as of June 30, 2026. Related ARCH entities and committee members may be deemed to share voting and dispositive power over these shares.

Who are the reporting persons in the Parabilis Medicines (PBLS) Schedule 13G?

The reporting persons are ARCH Venture Fund XII, L.P., ARCH Venture Partners XII, L.P., ARCH Venture Partners XII, LLC, and committee members Keith Crandell, Robert Nelsen, Kristina Burow, and Steven Gillis, who together report beneficial ownership of the same 6,412,780 shares.

What voting power do the ARCH entities have over Parabilis Medicines (PBLS) shares?

Each reporting person reports 0 shares with sole voting power and 6,412,780 shares with shared voting power. They also report the same 6,412,780 shares with shared dispositive power, reflecting coordinated control over this block.

On what share count is ARCH’s 5.3% stake in Parabilis Medicines (PBLS) based?

The reported 5.3% ownership is calculated using 121,952,030 shares of Common Stock outstanding as of August 10, 2026, a figure attributed to Parabilis Medicines’ Quarterly Report on Form 10-Q filed on August 13, 2026.

Do the ARCH reporting persons fully admit beneficial ownership of Parabilis Medicines (PBLS) shares?

Each reporting person disclaims beneficial ownership of the 6,412,780 shares except for any shares held of record in that person’s own name, limiting their acknowledgment to the extent of direct holdings.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Available on EDGAR 08/14/2026 - 04:08 PM Accepted by SEC EDGAR 08/14/2026 - 04:05 PM Learn about SEC filing dates

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

Parabilis Medicines, Inc.

(Name of Issuer)

Common Stock, $0.0001 par value

(Title of Class of Securities)

698955101

(CUSIP Number)

06/30/2026

(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)

schemaVersion:

SCHEDULE 13G

CUSIP Number(s): 698955101

1

Names of Reporting Persons

ARCH Venture Fund XII, 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 0.00
6	Shared Voting Power 6,412,780.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 6,412,780.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

6,412,780.00

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)

5.3 %

12

Type of Reporting Person (See Instructions)

PN

SCHEDULE 13G

CUSIP Number(s): 698955101

1

Names of Reporting Persons

ARCH Venture Partners XII, 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 0.00
6	Shared Voting Power 6,412,780.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 6,412,780.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

6,412,780.00

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)

5.3 %

12

Type of Reporting Person (See Instructions)

PN

SCHEDULE 13G

CUSIP Number(s): 698955101

1

Names of Reporting Persons

ARCH Venture Partners XII, 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 0.00
6	Shared Voting Power 6,412,780.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 6,412,780.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

6,412,780.00

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)

5.3 %

12

Type of Reporting Person (See Instructions)

OO

SCHEDULE 13G

CUSIP Number(s): 698955101

1

Names of Reporting Persons

Robert Nelsen

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

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

9

Aggregate Amount Beneficially Owned by Each Reporting Person

6,412,780.00

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)

5.3 %

12

Type of Reporting Person (See Instructions)

IN

SCHEDULE 13G

CUSIP Number(s): 698955101

1

Names of Reporting Persons

Keith Crandell

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

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

9

Aggregate Amount Beneficially Owned by Each Reporting Person

6,412,780.00

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)

5.3 %

12

Type of Reporting Person (See Instructions)

IN

SCHEDULE 13G

CUSIP Number(s): 698955101

1

Names of Reporting Persons

Kristina Burow

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

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

9

Aggregate Amount Beneficially Owned by Each Reporting Person

6,412,780.00

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)

5.3 %

12

Type of Reporting Person (See Instructions)

IN

SCHEDULE 13G

CUSIP Number(s): 698955101

1

Names of Reporting Persons

Steven Gillis

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

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

9

Aggregate Amount Beneficially Owned by Each Reporting Person

6,412,780.00

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)

5.3 %

12

Type of Reporting Person (See Instructions)

IN

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 Number(s): 698955101
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.
	Not Applicable
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