Filing Details

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

Name of Reporting Persons.

Frazier Life Sciences VIII, L.P.

Check the Appropriate Box if a Member of a Group (See Instructions)

(a)  ☐        (b)  ☒

SEC USE ONLY

Source of Funds (See Instructions)

WC

Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e)

☐

Citizenship or Place of Organization

Delaware

Number of

Shares

Beneficially

Owned by

Each

Reporting

Person

With:

Sole Voting Power

0 shares

Shared Voting Power

10,542,790 shares (1)

Sole Dispositive Power

0 shares

Shared Dispositive Power

10,542,790 shares (1)

Aggregate Amount Beneficially Owned by Each Reporting Person

10,542,790 shares (1)

Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions)

☐

Percent of Class Represented by Amount in Row (11)

27.7% (2)

Type of Reporting Person (See Instructions)

PN

Consists of 10,542,790 shares of Common Stock held directly by Frazier Life Sciences VIII, L.P. FHM Life Sciences VIII, L.P. is the general partner of Frazier Life Sciences VIII, L.P. and FHM Life Sciences VIII, L.L.C. is the general partner of FHM Life Sciences VIII, L.P. James N. Topper and Patrick J. Heron are the sole members of FHM Life Sciences VIII, L.L.C. and therefore share voting and investment power over the shares held by Frazier Life Sciences VIII, L.P.

Based on 38,033,156 shares of Common Stock that were anticipated to be outstanding following the Issuers initial public offering as set forth in the Issuers final prospectus filed with the SEC pursuant to Rule 424(b)(4) on January 31, 2020.

Name of Reporting Persons.

FHM Life Sciences VIII, L.P.

Check the Appropriate Box if a Member of a Group (See Instructions)

(a)  ☐        (b)  ☒

SEC USE ONLY

Source of Funds (See Instructions)

AF

Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e)

☐

Citizenship or Place of Organization

Delaware

Number of

Shares

Beneficially

Owned by

Each

Reporting

Person

With:

Sole Voting Power

0 shares

Shared Voting Power

10,542,790 shares (1)

Sole Dispositive Power

0 shares

Shared Dispositive Power

10,542,790 shares (1)

Aggregate Amount Beneficially Owned by Each Reporting Person

10,542,790 shares (1)

Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions)

☐

Percent of Class Represented by Amount in Row (11)

27.7% (2)

Type of Reporting Person (See Instructions)

PN

Consists of 10,542,790 shares of Common Stock held directly by Frazier Life Sciences VIII, L.P. FHM Life Sciences VIII, L.P. is the general partner of Frazier Life Sciences VIII, L.P. and FHM Life Sciences VIII, L.L.C. is the general partner of FHM Life Sciences VIII, L.P. James N. Topper and Patrick J. Heron are the sole members of FHM Life Sciences VIII, L.L.C. and therefore share voting and investment power over the shares held by Frazier Life Sciences VIII, L.P.

Based on 38,033,156 shares of Common Stock that were anticipated to be outstanding following the Issuers initial public offering as set forth in the Issuers final prospectus filed with the SEC pursuant to Rule 424(b)(4) on January 31, 2020.

Name of Reporting Persons.

FHM Life Sciences VIII, L.L.C.

Check the Appropriate Box if a Member of a Group (See Instructions)

(a)  ☐        (b)  ☒

SEC USE ONLY

Source of Funds (See Instructions)

AF

Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e)

☐

Citizenship or Place of Organization

Delaware

Number of

Shares

Beneficially

Owned by

Each

Reporting

Person

With:

Sole Voting Power

0 shares

Shared Voting Power

10,542,790 shares (1)

Sole Dispositive Power

0

Shared Dispositive Power

10,542,790 shares (1)

Aggregate Amount Beneficially Owned by Each Reporting Person

10,542,790 shares (1)

Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions)

☐

Percent of Class Represented by Amount in Row (11)

27.7% (2)

Type of Reporting Person (See Instructions)

OO

Consists of 10,542,790 shares of Common Stock held directly by Frazier Life Sciences VIII, L.P. FHM Life Sciences VIII, L.P. is the general partner of Frazier Life Sciences VIII, L.P. and FHM Life Sciences VIII, L.L.C. is the general partner of FHM Life Sciences VIII, L.P. James N. Topper and Patrick J. Heron are the sole members of FHM Life Sciences VIII, L.L.C. and therefore share voting and investment power over the shares held by Frazier Life Sciences VIII, L.P.

Based on 38,033,156 shares of Common Stock that were anticipated to be outstanding following the Issuers initial public offering as set forth in the Issuers final prospectus filed with the SEC pursuant to Rule 424(b)(4) on January 31, 2020.

Name of Reporting Persons.

James N. Topper

Check the Appropriate Box if a Member of a Group (See Instructions)

(a)  ☐        (b)  ☒

SEC USE ONLY

Source of Funds (See Instructions)

AF

Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e)

☐

Citizenship or Place of Organization

United States Citizen

Number of

Shares

Beneficially

Owned by

Each

Reporting

Person

With:

Sole Voting Power

0 shares

Shared Voting Power

10,542,790 shares (1)

Sole Dispositive Power

0 shares

Shared Dispositive Power

10,542,790 shares (1)

Aggregate Amount Beneficially Owned by Each Reporting Person

10,542,790 shares (1)

Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions)

☐

Percent of Class Represented by Amount in Row (11)

27.7% (2)

Type of Reporting Person (See Instructions)

IN

Consists of 10,542,790 shares of Common Stock held directly by Frazier Life Sciences VIII, L.P. FHM Life Sciences VIII, L.P. is the general partner of Frazier Life Sciences VIII, L.P. and FHM Life Sciences VIII, L.L.C. is the general partner of FHM Life Sciences VIII, L.P. James N. Topper and Patrick J. Heron are the sole members of FHM Life Sciences VIII, L.L.C. and therefore share voting and investment power over the shares held by Frazier Life Sciences VIII, L.P.

Based on 38,033,156 shares of Common Stock that were anticipated to be outstanding following the Issuers initial public offering as set forth in the Issuers final prospectus filed with the SEC pursuant to Rule 424(b)(4) on January 31, 2020.

Name of Reporting Persons.

Patrick J. Heron

Check the Appropriate Box if a Member of a Group (See Instructions)

(a)  ☐        (b)  ☒

SEC USE ONLY

Source of Funds (See Instructions)

AF

Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e)

☐

Citizenship or Place of Organization

United States Citizen

Number of

Shares

Beneficially

Owned by

Each

Reporting

Person

With:

Sole Voting Power

0 shares

Shared Voting Power

10,542,790 shares (1)

Sole Dispositive Power

0 shares

Shared Dispositive Power

10,542,790 shares (1)

Aggregate Amount Beneficially Owned by Each Reporting Person

10,542,790 shares (1)

Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions)

☐

Percent of Class Represented by Amount in Row (11)

27.7% (2)

Type of Reporting Person (See Instructions)

IN

Consists of 10,542,790 shares of Common Stock held directly by Frazier Life Sciences VIII, L.P. FHM Life Sciences VIII, L.P. is the general partner of Frazier Life Sciences VIII, L.P. and FHM Life Sciences VIII, L.L.C. is the general partner of FHM Life Sciences VIII, L.P. James N. Topper and Patrick J. Heron are the sole members of FHM Life Sciences VIII, L.L.C. and therefore share voting and investment power over the shares held by Frazier Life Sciences VIII, L.P.

Based on 38,033,156 shares of Common Stock that were anticipated to be outstanding following the Issuers initial public offering as set forth in the Issuers final prospectus filed with the SEC pursuant to Rule 424(b)(4) on January 31, 2020.

Security and Issuer.

Identity and Background

Name:

Residence or Business Address:

Present principal occupation or employment and the name, principal business and address of any corporation or other organization in which such employment is conducted:

Whether or not, during the last five years, such person has been convicted in a criminal proceeding (excluding traffic violations or similar misdemeanors) and, if so, give the dates, nature of conviction, name and location of court, and penalty imposed, or other disposition of the case:

Whether or not, during the last five years, such person was a party to a civil proceeding of a judicial or administrative body of competent jurisdiction and as a result of such proceeding was or is subject to a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violation with respect to such laws; and, if so, identify and describe such proceedings and summarize the terms of such judgment, decree or final order:

Citizenship:

Source and Amount of Funds or Other Consideration

Purpose of Transaction

The acquisition by any person of additional securities of the Issuer, or the disposition of securities of the Issuer;

An extraordinary corporate transaction, such as a merger, reorganization or liquidation, involving the Issuer or any of its subsidiaries;

A sale or transfer of a material amount of assets of the Issuer or any of its subsidiaries;

Any change in the present board of directors or management of the Issuer, including any plans or proposals to change the number or term of directors or to fill any existing vacancies on the board;

Any material change in the present capitalization or dividend policy of the Issuer;

Any other material change in the Issuers business or corporate structure;

Changes in the Issuers charter, bylaws or instruments corresponding thereto or other actions which may impede the acquisition of control of the Issuer by any person;

Causing a class of securities of the Issuer to be delisted from a national securities exchange or to cease to be authorized to be quoted in an inter-dealer quotation system of a registered national securities association;

A class of equity securities of the Issuer becoming eligible for termination of registration pursuant to Section 12(g)(4) of the Securities Exchange Act of 1934, as amended; or

Any action similar to any of those enumerated above.

Interest in Securities of the Issuer

State the aggregate number and percentage of the class of securities identified pursuant to Item 1 (which may be based on the number of securities outstanding as contained in the most recently available filing with the Commission by the issuer unless the filing person has reason to believe such information is not current) beneficially owned (identifying those shares which there is a right to acquire) by each person named in Item 2. The information should also be furnished with respect to persons who, together with any of the persons named in Item 2, comprise a group within the meaning of Section 13(d)(3) of the Act:

For each person named in response to paragraph (a), indicate the number of shares as to which there is sole power to vote or to direct the vote, shared power to vote or to direct the vote, sole power to dispose or to direct the disposition, or shared power to dispose or to direct the disposition. Provide the applicable information required by Item 2 with respect to each person with whom the power to vote or to direct the vote or to dispose or direct the disposition is shared:

Sole power to vote or to direct the vote: See line 7 of cover sheets.

Shared power to vote or to direct the vote: See line 8 of cover sheets.

Sole power to dispose or to direct the disposition: See line 9 of cover sheets.

Shared power to dispose or to direct the disposition: See line 10 of cover sheets.

Describe any transactions in the class of securities reported on that were effected during the past sixty days or since the most recent filing of Schedule 13D (§240.13d-191), whichever is less, by the persons named in response to paragraph (a):

Date of

Transaction

Type of

Transaction

Quantity

Class of Stock

Price Per Share

(excluding

commissions)

Date of

Transaction

Type of

Transaction

Quantity

Class of Stock

Price Per Share

(excluding

commissions)

Date of

Transaction

Type of

Transaction

Quantity

Class of Stock

Price Per Share

(excluding

commissions)

Date of

Transaction

Type of

Transaction

Quantity

Class of Stock

Price Per Share

(excluding

commissions)

Date of Transaction

Type of Transaction

Quantity

Class of Stock

Price Per Share

(excluding

commissions)

If any other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities, a statement to that effect should be included in response to this item and, if such interest relates to more than five percent of the class, such person should be identified. A listing of the shareholders of an investment company registered under the

If applicable, state the date on which the reporting person ceased to be the beneficial owner of more than five percent of the class of securities:

Contracts, Arrangements, Understandings or Relationships with Respect to Securities of the Issuer

Material to Be Filed as Exhibits

Agreement regarding filing of joint Schedule 13D.

Form of Lock-up Agreement.

Amended and Restated Investors Rights Agreement.

Agreement regarding filing of joint Schedule 13D.

Form of Lock-up Agreement (incorporated by reference to Annex I to that certain Underwriting Agreement between the Issuer and the Underwriters (as defined therein) filed as Exhibit 1.1 to the Issuers Registration Statement on Form S-1/A filed with the Commission on January 21, 2020).

Amended and Restated Investors Rights Agreement (incorporated by reference to Exhibit 4.2 to the Issuers Registration Statement on Form S-1 filed with the Commission on January 6, 2020).