SCHEDULE 13G

CUSIP No.

98422T100

Names of Reporting Persons

Frazier Life Sciences Public Fund, 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 3,508,661.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 3,508,661.00

Aggregate Amount Beneficially Owned by Each Reporting Person

3,508,661.00

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)

6.3 %

Type of Reporting Person (See Instructions)

Comment for Type of Reporting Person: The shares listed in rows 6, 8 and 9 consist of 3,508,661 shares of Common Stock issuable to Frazier Life Sciences Public Fund, L.P. pursuant to pre-funded warrants exercisable within 60 days of June 5, 2025. FHMLSP, L.P. is the general partner of Frazier Life Sciences Public Fund, L.P. and FHMLSP, L.L.C. is the general partner of FHMLSP, L.P. Patrick J. Heron, James N. Topper, Albert Cha and James Brush are the members of FHMLSP, L.L.C. and therefore share voting and investment power over the shares held by Frazier Life Sciences Public Fund, L.P. The percentage listed in row 11 is calculated based the sum of (i) 51,782,273 shares of the Issuer's Common Stock outstanding as of May 5, 2025, as reported in the Issuer's Quarterly Report on Form 10-Q filed with the SEC on May 8, 2025, and (ii) 3,508,661 shares of Common Stock issuable to Frazier Life Sciences Public Fund, L.P. pursuant to pre-funded warrants exercisable within 60 days of June 5, 2025.

SCHEDULE 13G

CUSIP No.

98422T100

Names of Reporting Persons

FHMLSP, 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 3,508,661.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 3,508,661.00

Aggregate Amount Beneficially Owned by Each Reporting Person

3,508,661.00

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)

6.3 %

Type of Reporting Person (See Instructions)

SCHEDULE 13G

CUSIP No.

98422T100

Names of Reporting Persons

FHMLSP, L.L.C.

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 3,508,661.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 3,508,661.00

Aggregate Amount Beneficially Owned by Each Reporting Person

3,508,661.00

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)

6.3 %

Type of Reporting Person (See Instructions)

SCHEDULE 13G

CUSIP No.

98422T100

Names of Reporting Persons

Frazier Life Sciences Public Overage Fund, 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 1,035,069.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 1,035,069.00

Aggregate Amount Beneficially Owned by Each Reporting Person

1,035,069.00

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)

2.0 %

Type of Reporting Person (See Instructions)

Comment for Type of Reporting Person: The shares listed in rows 6, 8 and 9 consist of 1,035,069 shares of Common Stock issuable to Frazier Life Sciences Public Overage Fund, L.P. pursuant to pre-funded warrants exercisable within 60 days of June 5, 2025. FHMLSP Overage, L.P. is the general partner of Frazier Life Sciences Public Overage Fund, L.P. and FHMLSP Overage, L.L.C. is the general partner of FHMLSP Overage, L.P. Patrick J. Heron, James N. Topper, Albert Cha and James Brush are the members of FHMLSP Overage, L.L.C. and therefore share voting and investment power over the shares held by Frazier Life Sciences Public Overage Fund, L.P. The percentage listed in row 11 is calculated based the sum of (i) 51,782,273 shares of the Issuer's Common Stock outstanding as of May 5, 2025, as reported in the Issuer's Quarterly Report on Form 10-Q filed with the SEC on May 8, 2025 and (ii) 1,035,069 shares of Common Stock issuable to Frazier Life Sciences Public Overage Fund, L.P. pursuant to pre-funded warrants exercisable within 60 days of June 5, 2025.

SCHEDULE 13G

CUSIP No.

98422T100

Names of Reporting Persons

FHMLSP Overage, 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 1,035,069.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 1,035,069.00

Aggregate Amount Beneficially Owned by Each Reporting Person

1,035,069.00

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)

2.0 %

Type of Reporting Person (See Instructions)

SCHEDULE 13G

CUSIP No.

98422T100

Names of Reporting Persons

FHMLSP Overage, L.L.C.

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 1,035,069.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 1,035,069.00

Aggregate Amount Beneficially Owned by Each Reporting Person

1,035,069.00

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)

2.0 %

Type of Reporting Person (See Instructions)

SCHEDULE 13G

CUSIP No.

98422T100

Names of Reporting Persons

Frazier Life Sciences X, 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 144,829.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 144,829.00

Aggregate Amount Beneficially Owned by Each Reporting Person

144,829.00

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)

0.3 %

Type of Reporting Person (See Instructions)

Comment for Type of Reporting Person: The shares listed in rows 6, 8 and 9 consist of 144,829 shares of Common Stock issuable to Frazier Life Sciences X, L.P. pursuant to pre-funded warrants exercisable within 60 days of June 5, 2025. FHMLS X, L.P. is the general partner of Frazier Life Sciences X, L.P. and FHMLS X, L.L.C. is the general partner of FHMLS X, L.P. Patrick J. Heron and James N. Topper are the members of FHMLS X, L.L.C. and therefore share voting and investment power over the shares held by Frazier Life Sciences X, L.P. The percentage listed in row 11 is calculated based the sum of (i) 51,782,273 shares of the Issuer's Common Stock outstanding as of May 5, 2025, as reported in the Issuer's Quarterly Report on Form 10-Q filed with the SEC on May 8, 2025, and (ii) 144,829 shares of Common Stock issuable to Frazier Life Sciences X, L.P. pursuant to pre-funded warrants exercisable within 60 days of June 5, 2025.

SCHEDULE 13G

CUSIP No.

98422T100

Names of Reporting Persons

FHMLS X, 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 144,829.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 144,829.00

Aggregate Amount Beneficially Owned by Each Reporting Person

144,829.00

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)

0.3 %

Type of Reporting Person (See Instructions)

SCHEDULE 13G

CUSIP No.

98422T100

Names of Reporting Persons

FHMLS X, L.L.C.

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 144,829.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 144,829.00

Aggregate Amount Beneficially Owned by Each Reporting Person

144,829.00

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)

0.3 %

Type of Reporting Person (See Instructions)

SCHEDULE 13G

CUSIP No.

98422T100

Names of Reporting Persons

Frazier Life Sciences XI, 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 385,637.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 385,637.00

Aggregate Amount Beneficially Owned by Each Reporting Person

385,637.00

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)

0.7 %

Type of Reporting Person (See Instructions)

Comment for Type of Reporting Person: The shares listed in rows 6, 8 and 9 consist of 385,637 shares of Common Stock issuable to Frazier Life Sciences XI, L.P. pursuant to pre-funded warrants exercisable within 60 days of June 5, 2025. FHMLS XI, L.P. is the general partner of Frazier Life Sciences XI, L.P. and FHMLS XI, L.L.C. is the general partner of FHMLS XI, L.P. Patrick J. Heron, James N. Topper and Daniel Estes are the members of FHMLS XI, L.L.C. and therefore share voting and investment power over the shares held by Frazier Life Sciences XI, L.P. The percentage listed in row 11 is calculated based the sum of (i) 51,782,273 shares of the Issuer's Common Stock outstanding as of May 5, 2025, as reported in the Issuer's Quarterly Report on Form 10-Q filed with the SEC on May 8, 2025, and (ii) 385,637 shares of Common Stock issuable to Frazier Life Sciences XI, L.P. pursuant to pre-funded warrants exercisable within 60 days of June 5, 2025.

SCHEDULE 13G

CUSIP No.

98422T100

Names of Reporting Persons

FHMLS XI, 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 385,637.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 385,637.00

Aggregate Amount Beneficially Owned by Each Reporting Person

385,637.00

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)

0.7 %

Type of Reporting Person (See Instructions)

SCHEDULE 13G

CUSIP No.

98422T100

Names of Reporting Persons

FHMLS XI, L.L.C.

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 385,637.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 385,637.00

Aggregate Amount Beneficially Owned by Each Reporting Person

385,637.00

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)

0.7 %

Type of Reporting Person (See Instructions)

SCHEDULE 13G

CUSIP No.

98422T100

Names of Reporting Persons

Frazier Life Sciences 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 672,997.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 672,997.00

Aggregate Amount Beneficially Owned by Each Reporting Person

672,997.00

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)

1.3 %

Type of Reporting Person (See Instructions)

Comment for Type of Reporting Person: The shares listed in rows 6, 8 and 9 consist of 672,997 shares of Common Stock issuable to Frazier Life Sciences XII, L.P. pursuant to pre-funded warrants exercisable within 60 days of June 5, 2025. FHMLS XII, L.P. is the general partner of Frazier Life Sciences XII, L.P. and FHMLS XII, L.L.C. is the general partner of FHMLS XII, L.P. Patrick J. Heron, James N. Topper and Daniel Estes are the members of FHMLS XII, L.L.C. and therefore share voting and investment power over the shares held by Frazier Life Sciences XII, L.P. The percentage listed in row 11 is calculated based the sum of (i) 51,782,273 shares of the Issuer's Common Stock outstanding as of May 5, 2025, as reported in the Issuer's Quarterly Report on Form 10-Q filed with the SEC on May 8, 2025, and (ii) 672,997 shares of Common Stock issuable to Frazier Life Sciences XII, L.P. pursuant to pre-funded warrants exercisable within 60 days of June 5, 2025.

SCHEDULE 13G

CUSIP No.

98422T100

Names of Reporting Persons

FHMLS 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 672,997.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 672,997.00

Aggregate Amount Beneficially Owned by Each Reporting Person

672,997.00

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)

1.3 %

Type of Reporting Person (See Instructions)

SCHEDULE 13G

CUSIP No.

98422T100

Names of Reporting Persons

FHMLS XII, L.L.C.

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 672,997.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 672,997.00

Aggregate Amount Beneficially Owned by Each Reporting Person

672,997.00

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)

1.3 %

Type of Reporting Person (See Instructions)

SCHEDULE 13G

CUSIP No.

98422T100

Names of Reporting Persons

James N. Topper

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 5,747,193.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 5,747,193.00

Aggregate Amount Beneficially Owned by Each Reporting Person

5,747,193.00

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)

9.9 %

Type of Reporting Person (See Instructions)

Comment for Type of Reporting Person: The shares listed in rows 6, 8 and 9 consist of (i) 3,508,661 shares of Common Stock issuable to Frazier Life Sciences Public Fund, L.P. pursuant to pre-funded warrants exercisable within 60 days of June 5, 2025, (ii) 1,035,069 shares of Common Stock issuable to Frazier Life Sciences Public Overage Fund, L.P. pursuant to pre-funded warrants exercisable within 60 days of June 5, 2025, (iii) 144,829 shares of Common Stock issuable to Frazier Life Sciences X, L.P. pursuant to pre-funded warrants exercisable within 60 days of June 5, 2025, (iv) 385,637 shares of Common Stock issuable to Frazier Life Sciences XI, L.P. pursuant to pre-funded warrants exercisable within 60 days of June 5, 2025, and (v) 672,997 shares of Common Stock issuable to Frazier Life Sciences XII, L.P. pursuant pre-funded warrants exercisable within 60 days of June 5, 2025. FHMLSP, L.P. is the general partner of Frazier Life Sciences Public Fund, L.P. and FHMLSP, L.L.C. is the general partner of FHMLSP, L.P. Patrick J. Heron, James N. Topper, Albert Cha and James Brush are the members of FHMLSP, L.L.C. and therefore share voting and investment power over the shares held by Frazier Life Sciences Public Fund, L.P. FHMLSP Overage, L.P. is the general partner of Frazier Life Sciences Public Overage Fund, L.P. and FHMLSP Overage, L.L.C. is the general partner of FHMLSP Overage, L.P. Patrick J. Heron, James N. Topper, Albert Cha and James Brush are the members of FHMLSP Overage, L.L.C. and therefore share voting and investment power over the shares held by Frazier Life Sciences Public Overage Fund, L.P. FHMLS X, L.P. is the general partner of Frazier Life Sciences X, L.P. and FHMLS X, L.L.C. is the general partner of FHMLS X, L.P. Patrick J. Heron and James N. Topper are the members of FHMLS X, L.L.C. and therefore share voting and investment power over the shares held by Frazier Life Sciences X, L.P. FHMLS XI, L.P. is the general partner of Frazier Life Sciences XI, L.P. and FHMLS XI, L.L.C. is the general partner of FHMLS XI, L.P. Patrick J. Heron, James N. Topper and Daniel Estes are the members of FHMLS XI, L.L.C. and therefore share voting and investment power over the shares held by Frazier Life Sciences XI, L.P. FHMLS XII, L.P. is the general partner of Frazier Life Sciences XII, L.P. and FHMLS XII, L.L.C. is the general partner of FHMLS XII, L.P. Patrick J. Heron, James N. Topper and Daniel Estes are the members of FHMLS XII, L.L.C. and therefore share voting and investment power over the shares held by Frazier Life Sciences XII, L.P. The percentage listed in row 11 is calculated based the sum of (i) 51,782,273 shares of the Issuer's Common Stock outstanding as of May 5, 2025, as reported in the Issuer's Quarterly Report on Form 10-Q filed with the SEC on May 8, 2025, (ii) 3,508,661 shares of Common Stock issuable to Frazier Life Sciences Public Fund, L.P. pursuant to pre-funded warrants exercisable within 60 days of June 5, 2025, (iii) 1,035,069 shares of Common Stock issuable to Frazier Life Sciences Public Overage Fund, L.P. pursuant to pre-funded warrants exercisable within 60 days of June 5, 2025, (iv) 144,829 shares of Common Stock issuable to Frazier Life Sciences X, L.P. pursuant to pre-funded warrants exercisable within 60 days of June 5, 2025, (v) 385,637 shares of Common Stock issuable to Frazier Life Sciences XI, L.P. pursuant to pre-funded warrants exercisable within 60 days of June 5, 2025, (vi) 672,997 shares of Common Stock issuable to Frazier Life Sciences XII, L.P. pursuant pre-funded warrants exercisable within 60 days of June 5, 2025.

SCHEDULE 13G

CUSIP No.

98422T100

Names of Reporting Persons

Patrick J. Heron

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 5,747,193.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 5,747,193.00

Aggregate Amount Beneficially Owned by Each Reporting Person

5,747,193.00

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)

9.9 %

Type of Reporting Person (See Instructions)

SCHEDULE 13G

CUSIP No.

98422T100

Names of Reporting Persons

Albert Cha

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 4,543,730.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 4,543,730.00

Aggregate Amount Beneficially Owned by Each Reporting Person

4,543,730.00

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)

8.1 %

Type of Reporting Person (See Instructions)

SCHEDULE 13G

CUSIP No.

98422T100

Names of Reporting Persons

James Brush

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 4,543,730.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 4,543,730.00

Aggregate Amount Beneficially Owned by Each Reporting Person

4,543,730.00

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)

8.1 %

Type of Reporting Person (See Instructions)

SCHEDULE 13G

CUSIP No.

98422T100

Names of Reporting Persons

Daniel Estes

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 1,058,634.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 1,058,634.00

Aggregate Amount Beneficially Owned by Each Reporting Person

1,058,634.00

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)

2.0 %

Type of Reporting Person (See Instructions)

Comment for Type of Reporting Person: The shares listed in rows 6, 8 and 9 consist of (i) 385,637 shares of Common Stock issuable to Frazier Life Sciences XI, L.P. pursuant to pre-funded warrants exercisable within 60 days of June 5, 2025, and (ii) 672,997 shares of Common Stock issuable to Frazier Life Sciences XII, L.P. pursuant pre-funded warrants exercisable within 60 days of June 5, 2025. FHMLS XI, L.P. is the general partner of Frazier Life Sciences XI, L.P. and FHMLS XI, L.L.C. is the general partner of FHMLS XI, L.P. Patrick J. Heron, James N. Topper and Daniel Estes are the members of FHMLS XI, L.L.C. and therefore share voting and investment power over the shares held by Frazier Life Sciences XI, L.P. FHMLS XII, L.P. is the general partner of Frazier Life Sciences XII, L.P. and FHMLS XII, L.L.C. is the general partner of FHMLS XII, L.P. Patrick J. Heron, James N. Topper and Daniel Estes are the members of FHMLS XII, L.L.C. and therefore share voting and investment power over the shares held by Frazier Life Sciences XII, L.P. The percentage listed in row 11 is calculated based the sum of (i) 51,782,273 shares of the Issuer's Common Stock outstanding as of May 5, 2025, as reported in the Issuer's Quarterly Report on Form 10-Q filed with the SEC on May 8, 2025, (ii) 385,637 shares of Common Stock issuable to Frazier Life Sciences XI, L.P. pursuant to pre-funded warrants exercisable within 60 days of June 5, 2025, and (iii) 672,997 shares of Common Stock issuable to Frazier Life Sciences XII, L.P. pursuant pre-funded warrants exercisable within 60 days of June 5, 2025.

SCHEDULE 13G

Item 1.

(a)

Name of issuer:

Xilio Therapeutics, Inc.

(b)

Address of issuer's principal executive offices:

828 Winter Street, Suite 300, Waltham, MA, 02451.

Item 2.

(a)

Name of person filing:

The entities and persons filing this statement (collectively, the "Reporting Persons") are: Frazier Life Sciences Public Fund, L.P. ("FLSPF") FHMLSP, L.P. FHMLSP, L.L.C. Frazier Life Sciences Public Overage Fund, L.P. ("FLSPOF") FHMLSP Overage, L.P. FHMLSP Overage, L.L.C. Frazier Life Sciences X, L.P. ("FLS X") FHMLS X, L.P. FHMLS X, L.L.C. Frazier Life Sciences XI, L.P. ("FLS XI") FHMLS XI, L.P. FHMLS XI, L.L.C. Frazier Life Sciences XII, L.P. ("FLS XII") FHMLS XII, L.P. FHMLS XII, L.L.C. James N. Topper ("Topper") Patrick J. Heron ("Heron") Albert Cha ("Cha") James Brush ("Brush") Daniel Estes ("Estes" and together with Topper, Heron, Cha and Brush, the "Members")

(b)

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

The address of the principal place of business for each of the Reporting Persons is: c/o Frazier Life Sciences Management, L.P. 1001 Page Mill Rd, Building 4, Suite B Palo Alto, CA 94304

(c)

Citizenship:

Entities: FLSPF - Delaware, U.S.A. FHMLSP, L.P. - Delaware, U.S.A. FHMLSP, L.L.C. - Delaware, U.S.A. FLSPOF - Delaware, U.S.A. FHMLSP Overage, L.P. - Delaware, U.S.A. FHMLSP Overage, L.L.C. - Delaware, U.S.A. FLS X - Delaware, U.S.A. FHMLS X, L.P. - Delaware, U.S.A. FHMLS X, L.L.C. - Delaware, U.S.A. FLS XI - Delaware, U.S.A. FHMLS XI, L.P. - Delaware, U.S.A. FHMLS XI, L.L.C. - Delaware, U.S.A. FLS XII - Delaware, U.S.A. FHMLS XII, L.P. - Delaware, U.S.A. FHMLS XII, L.L.C. - Delaware, U.S.A. Individuals: Topper - United States Citizen Heron - United States Citizen Cha - United States Citizen Brush - United States Citizen Estes - United States Citizen

(d)

Title of class of securities:

Common Stock, par value $0.0001 per share

(e)

CUSIP No.:

98422T100

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:

The information contained in row 9 of each Reporting Person's cover page to this Schedule 13G (including the footnotes thereto) is incorporated by reference.

(b)

Percent of class:

The information contained in row 11 of each Reporting Person's cover page to this Schedule 13G (including the footnotes thereto) is incorporated by reference. Due to field limitations of the EDGAR filing system, the percentages listed in Row 11 of Topper's and Heron's cover pages have been rounded down from 9.99% to 9.9%.

(c)

Number of shares as to which the person has:

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

The information contained in row 5 of each Reporting Person's cover page to this Schedule 13G is incorporated by reference.

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

The information contained in row 6 of each Reporting Person's cover page to this Schedule 13G (including the footnotes thereto) is incorporated by reference.

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

The information contained in row 7 of each Reporting Person's cover page to this Schedule 13G is incorporated by reference.

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

The information contained in row 8 of each Reporting Person's cover page to this Schedule 13G (including the footnotes thereto) is incorporated by reference.

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:

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11.

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.

Frazier Life Sciences Public Fund, L.P.

Signature:	/s/ Steve R. Bailey
Name/Title:	By Steve R. Bailey, CFO of FHMLSP, L.L.C., GP of FHMLSP, L.P., GP of Frazier Life Sciences Public Fund, L.P.
Date:	06/12/2025

FHMLSP, L.P.

Signature:	/s/ Steve R. Bailey
Name/Title:	By Steve R. Bailey, CFO of FHMLSP, L.L.C., GP of FHMLSP, L.P.
Date:	06/12/2025

FHMLSP, L.L.C.

Signature:	/s/ Steve R. Bailey
Name/Title:	By Steve R. Bailey, CFO of FHMLSP, L.L.C.
Date:	06/12/2025

Frazier Life Sciences Public Overage Fund, L.P.

Signature:	/s/ Steve R. Bailey
Name/Title:	By Steve R. Bailey, CFO of FHMLSP Overage, L.L.C., GP of FHMLSP Overage, L.P., GP of Frazier Life Sciences Public Overage Fund, L.P.
Date:	06/12/2025

FHMLSP Overage, L.P.

Signature:	/s/ Steve R. Bailey
Name/Title:	By Steve R. Bailey, CFO of FHMLSP Overage, L.L.C., GP of FHMLSP Overage, L.P.
Date:	06/12/2025

FHMLSP Overage, L.L.C.

Signature:	/s/ Steve R. Bailey
Name/Title:	By Steve R. Bailey, CFO of FHMLSP Overage, L.L.C.
Date:	06/12/2025

Frazier Life Sciences X, L.P.

Signature:	/s/ Steve R. Bailey
Name/Title:	By Steve R. Bailey, CFO of FHMLS X, L.L.C., GP of FHMLS X, L.P., GP of Frazier Life Sciences X, L.P.
Date:	06/12/2025

FHMLS X, L.P.

Signature:	/s/ Steve R. Bailey
Name/Title:	By Steve R. Bailey, CFO of FHMLS X, L.L.C., GP of FHMLS X, L.P.
Date:	06/12/2025

FHMLS X, L.L.C.

Signature:	/s/ Steve R. Bailey
Name/Title:	By Steve R. Bailey, CFO of FHMLS X, L.L.C.
Date:	06/12/2025

Frazier Life Sciences XI, L.P.

Signature:	/s/ Steve R. Bailey
Name/Title:	By Steve R. Bailey, CFO of FHMLS XI, L.L.C., GP of FHMLS XI, L.P., GP of Frazier Life Sciences XI, L.P.
Date:	06/12/2025

FHMLS XI, L.P.

Signature:	/s/ Steve R. Bailey
Name/Title:	By Steve R. Bailey, CFO of FHMLS XI, L.L.C., GP of FHMLS XI, L.P.
Date:	06/12/2025

FHMLS XI, L.L.C.

Signature:	/s/ Steve R. Bailey
Name/Title:	By Steve R. Bailey, CFO of FHMLS XI, L.L.C.
Date:	06/12/2025

Frazier Life Sciences XII, L.P.

Signature:	/s/ Gordon Empey
Name/Title:	By Gordon Empey, General Counsel of FHMLS XII, L.L.C., GP of FHMLS XII, L.P., GP of Frazier Life Sciences XII, L.P.
Date:	06/12/2025

FHMLS XII, L.P.

Signature:	/s/ Gordon Empey
Name/Title:	By Gordon Empey, General Counsel of FHMLS XII, L.L.C., GP of FHMLS XII, L.P.
Date:	06/12/2025

FHMLS XII, L.L.C.

Signature:	/s/ Gordon Empey
Name/Title:	By Gordon Empey, General Counsel of FHMLS XII, L.L.C.
Date:	06/12/2025

James N. Topper

Signature:	/s/ Steve R. Bailey
Name/Title:	By Steve R. Bailey, Attorney-in-Fact for James N. Topper, pursuant to a Power of Attorney, a copy of which was filed with the SEC on July 31, 2017
Date:	06/12/2025

Patrick J. Heron

Signature:	/s/ Steve R. Bailey
Name/Title:	By Steve R. Bailey, Attorney-in-Fact for Patrick J. Heron, pursuant to a Power of Attorney, a copy of which was filed with the SEC on July 31, 2017
Date:	06/12/2025

Albert Cha

Signature:	/s/ Steve R. Bailey
Name/Title:	By Steve R. Bailey, Attorney-in-Fact for Albert Cha, pursuant to a Power of Attorney, a copy of which was filed with the SEC on August 16, 2021
Date:	06/12/2025

James Brush

Signature:	/s/ Steve R. Bailey
Name/Title:	By Steve R. Bailey, Attorney-in-Fact for James Brush, pursuant to a Power of Attorney, a copy of which was filed with the SEC on August 16, 2021
Date:	06/12/2025

Daniel Estes

Signature:	/s/ Steve R. Bailey
Name/Title:	By Steve R. Bailey, Attorney-in-Fact for Daniel Estes, pursuant to a Power of Attorney, a copy of which was filed with the SEC on April 18, 2022
Date:	06/12/2025

Exhibit Information

Exhibit 99.1 Joint Filing Agreement.