# EDGAR Filing Document

**Accession Number:** 0001785173
**File Stem:** 0001104659-23-039248
**Filing Date:** 2023-3
**Character Count:** 25169
**Document Hash:** 31b79cd2e64f11994df109cd82924f9e
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001104659-23-039248.hdr.sgml**: 20230330

**ACCESSION NUMBER**: 0001104659-23-039248

**CONFORMED SUBMISSION TYPE**: SC 13D/A

**PUBLIC DOCUMENT COUNT**: 1

**FILED AS OF DATE**: 20230330

**DATE AS OF CHANGE**: 20230330

**GROUP MEMBERS**: PETER KOLCHINSKY

**GROUP MEMBERS**: RA CAPITAL HEALTHCARE FUND, L.P.

**GROUP MEMBERS**: RAJEEV SHAH

**SUBJECT COMPANY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** 89bio, Inc.
- **CENTRAL INDEX KEY:** 0001785173
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **IRS NUMBER:** 831114349
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** SC 13D/A
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 005-91200
- **FILM NUMBER:** 23781567

**BUSINESS ADDRESS:**
- **STREET 1:** 142 SANSOME STREET
- **STREET 2:** SECOND FLOOR
- **CITY:** SAN FRANCISCO
- **STATE:** CA
- **ZIP:** 94104
- **BUSINESS PHONE:** (415) 432-9270

**MAIL ADDRESS:**
- **STREET 1:** 142 SANSOME STREET
- **STREET 2:** SECOND FLOOR
- **CITY:** SAN FRANCISCO
- **STATE:** CA
- **ZIP:** 94104
**FILED BY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** RA CAPITAL MANAGEMENT, L.P.
- **CENTRAL INDEX KEY:** 0001346824
- **IRS NUMBER:** 830406777
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** SC 13D/A

**BUSINESS ADDRESS:**
- **STREET 1:** 200 BERKELEY STREET, 18TH FLOOR
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02116
- **BUSINESS PHONE:** 617-778-2500

**MAIL ADDRESS:**
- **STREET 1:** 200 BERKELEY STREET, 18TH FLOOR
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02116

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** RA CAPITAL MANAGEMENT, LLC
- **DATE OF NAME CHANGE:** 20051213

**UNITED STATES**

**SECURITIES AND EXCHANGE COMMISSION**

**Washington, D.C. 20549**

**SCHEDULE 13D/A**

**Under the Securities Exchange Act of 1934**

**(Amendment No. 6)\***

<u>89BIO, INC.</u> 

(Name of Issuer)

Common Stock, par value $0.001 per share

(Title of Class of Securities)

282559103

(CUSIP Number)

RA Capital Management, L.P.

200 Berkeley Street, 18<sup>th</sup> Floor

Boston, MA 02116

Telephone: 617.778.2500

Attn: Peter Kolchinsky

(Name, Address and Telephone Number of Person Authorized to<br> Receive Notices and Communications)

March 28, 2023

(Date of Event Which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box. ◻

**Note:** Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See Rule 13d-7 for other parties to whom copies are to be sent.

\* 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 disclosures provided in a prior cover page.

The information required on 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. 282559103

---

| | |
|:---|:---|
| &nbsp;&nbsp;1 | &nbsp;&nbsp; Names of Reporting Persons.<br>**RA Capital Management, L.P.** |
| &nbsp;&nbsp;2 | &nbsp;&nbsp;Check the Appropriate Box if a Member of a Group (See Instructions) |
|  | &nbsp;&nbsp;(a) ◻ |
|  | &nbsp;&nbsp;(b) ◻ |
| &nbsp;&nbsp;3 | &nbsp;&nbsp;SEC Use Only |
| &nbsp;&nbsp;4 | &nbsp;&nbsp; Source of Funds (See Instructions):<br> AF  |
| &nbsp;&nbsp;5 | &nbsp;&nbsp; Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e):<br> ◻  |
| &nbsp;&nbsp;6 | &nbsp;&nbsp; Citizenship or Place of Organization. **Delaware**  |
| &nbsp;&nbsp; Number<br> of Shares<br> Beneficially<br> Owned by<br> Each<br> Reporting<br> Person With | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 7 Sole Voting Power **0 shares**<br>|
| &nbsp;&nbsp; Number<br> of Shares<br> Beneficially<br> Owned by<br> Each<br> Reporting<br> Person With | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 8 Shared Voting Power **12,876,898 shares** |
| &nbsp;&nbsp; Number<br> of Shares<br> Beneficially<br> Owned by<br> Each<br> Reporting<br> Person With | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 9 Sole Dispositive Power **0 shares** |
| &nbsp;&nbsp; Number<br> of Shares<br> Beneficially<br> Owned by<br> Each<br> Reporting<br> Person With | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 10 Shared Dispositive Power **12,876,898 shares** |
| &nbsp;&nbsp;11 | &nbsp;&nbsp; Aggregate Amount Beneficially Owned by Each Reporting Person<br> **12,876,898 shares** |
| &nbsp;&nbsp;12 | &nbsp;&nbsp;Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions) ◻ |
| &nbsp;&nbsp;13 | &nbsp;&nbsp; Percent of Class Represented by Amount in Row (11)<br> **18%<u><sup>1</sup></u>** |
| &nbsp;&nbsp;14 | &nbsp;&nbsp;&nbsp;&nbsp; Type of Reporting Person (See Instructions)<br> **IA, PN** |

---

<u><sup>1</sup></u> The Reporting Person is the beneficial owner of 11,416,948 shares of the Issuer's Common Stock as well as conversion shares underlying each of 26,306 vested stock options (right to buy) and 25,194 stock options (right to buy) which will vest within 60 days held by Dr. Derek DiRocco for the benefit of RA Capital, and 2,816,900 warrants through which the Reporting Person has the right to acquire 1,408,450 Common Stock shares. The percentage calculation assumes that there are 71,518,648 outstanding shares of Common Stock of the Issuer, based on 70,058,698 outstanding shares of Common Stock of the Issuer as reported directly by the Issuer to the Reporting Persons as of March 29, 2023, and giving effect to the stock options and warrants referenced herein.

CUSIP No. 282559103

---

| | |
|:---|:---|
| &nbsp;&nbsp;1 | &nbsp;&nbsp; Names of Reporting Persons.<br>**Peter Kolchinsky** |
| &nbsp;&nbsp;2 | &nbsp;&nbsp;Check the Appropriate Box if a Member of a Group (See Instructions) |
|  | &nbsp;&nbsp;(a) ◻ |
|  | &nbsp;&nbsp;(b) ◻ |
| &nbsp;&nbsp;3 | &nbsp;&nbsp;SEC Use Only |
| &nbsp;&nbsp;4 | &nbsp;&nbsp; Source of Funds (See Instructions):<br> AF  |
| &nbsp;&nbsp;5 | &nbsp;&nbsp; Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e):<br> ◻  |
| &nbsp;&nbsp;6 | &nbsp;&nbsp; Citizenship or Place of Organization. **United States** |
| &nbsp;&nbsp; Number<br> of Shares<br> Beneficially<br> Owned by<br> Each<br> Reporting<br> Person With | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 7 Sole Voting Power **0 shares**<br>|
| &nbsp;&nbsp; Number<br> of Shares<br> Beneficially<br> Owned by<br> Each<br> Reporting<br> Person With | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 8 Shared Voting Power **12,876,898 shares** |
| &nbsp;&nbsp; Number<br> of Shares<br> Beneficially<br> Owned by<br> Each<br> Reporting<br> Person With | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 9 Sole Dispositive Power **0 shares** |
| &nbsp;&nbsp; Number<br> of Shares<br> Beneficially<br> Owned by<br> Each<br> Reporting<br> Person With | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 10 Shared Dispositive Power **12,876,898 shares** |
| &nbsp;&nbsp;11 | &nbsp;&nbsp; Aggregate Amount Beneficially Owned by Each Reporting Person<br> **12,876,898 shares** |
| &nbsp;&nbsp;12 | &nbsp;&nbsp;Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions) ◻ |
| &nbsp;&nbsp;13 | &nbsp;&nbsp; Percent of Class Represented by Amount in Row (11)<br> **18%<u><sup>2</sup></u>** |
| &nbsp;&nbsp;14 | &nbsp;&nbsp;&nbsp;&nbsp; Type of Reporting Person (See Instructions)<br> **HC, IN** |

---

<u><sup>2</sup></u> The Reporting Person is the beneficial owner of 11,416,948 shares of the Issuer's Common Stock as well as conversion shares underlying each of 26,306 vested stock options (right to buy) and 25,194 stock options (right to buy) which will vest within 60 days held by Dr. Derek DiRocco for the benefit of RA Capital, and 2,816,900 warrants through which the Reporting Person has the right to acquire 1,408,450 Common Stock shares. The percentage calculation assumes that there are 71,518,648 outstanding shares of Common Stock of the Issuer, based on 70,058,698 outstanding shares of Common Stock of the Issuer as reported directly by the Issuer to the Reporting Persons as of March 29, 2023, and giving effect to the stock options and warrants referenced herein.

CUSIP No. 282559103

---

| | |
|:---|:---|
| &nbsp;&nbsp;1 | &nbsp;&nbsp; Names of Reporting Persons.<br>**Rajeev Shah** |
| &nbsp;&nbsp;2 | &nbsp;&nbsp;Check the Appropriate Box if a Member of a Group (See Instructions) |
|  | &nbsp;&nbsp;(a) ◻ |
|  | &nbsp;&nbsp;(b) ◻ |
| &nbsp;&nbsp;3 | &nbsp;&nbsp;SEC Use Only |
| &nbsp;&nbsp;4 | &nbsp;&nbsp; Source of Funds (See Instructions):<br> AF  |
| &nbsp;&nbsp;5 | &nbsp;&nbsp; Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e):<br> ◻  |
| &nbsp;&nbsp;6 | &nbsp;&nbsp; Citizenship or Place of Organization. **United States** |
| &nbsp;&nbsp; Number<br> of Shares<br> Beneficially<br> Owned by<br> Each<br> Reporting<br> Person With | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 7 Sole Voting Power **0 shares**<br>|
| &nbsp;&nbsp; Number<br> of Shares<br> Beneficially<br> Owned by<br> Each<br> Reporting<br> Person With | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 8 Shared Voting Power **12,876,898 shares** |
| &nbsp;&nbsp; Number<br> of Shares<br> Beneficially<br> Owned by<br> Each<br> Reporting<br> Person With | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 9 Sole Dispositive Power **0 shares** |
| &nbsp;&nbsp; Number<br> of Shares<br> Beneficially<br> Owned by<br> Each<br> Reporting<br> Person With | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 10 Shared Dispositive Power **12,876,898 shares** |
| &nbsp;&nbsp;11 | &nbsp;&nbsp; Aggregate Amount Beneficially Owned by Each Reporting Person<br> **12,876,898 shares** |
| &nbsp;&nbsp;12 | &nbsp;&nbsp;Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions) ◻ |
| &nbsp;&nbsp;13 | &nbsp;&nbsp; Percent of Class Represented by Amount in Row (11)<br> **18%<u><sup>3</sup></u>** |
| &nbsp;&nbsp;14 | &nbsp;&nbsp;&nbsp;&nbsp; Type of Reporting Person (See Instructions)<br> **HC, IN** |

---

<u><sup>3</sup></u> The Reporting Person is the beneficial owner of 11,416,948 shares of the Issuer's Common Stock as well as conversion shares underlying each of 26,306 vested stock options (right to buy) and 25,194 stock options (right to buy) which will vest within 60 days held by Dr. Derek DiRocco for the benefit of RA Capital, and 2,816,900 warrants through which the Reporting Person has the right to acquire 1,408,450 Common Stock shares. The percentage calculation assumes that there are 71,518,648 outstanding shares of Common Stock of the Issuer, based on 70,058,698 outstanding shares of Common Stock of the Issuer as reported directly by the Issuer to the Reporting Persons as of March 29, 2023, and giving effect to the stock options and warrants referenced herein.

CUSIP No. 282559103

---

| | |
|:---|:---|
| &nbsp;&nbsp;1 | &nbsp;&nbsp; Names of Reporting Persons.<br>**RA Capital Healthcare Fund, L.P.** |
| &nbsp;&nbsp;2 | &nbsp;&nbsp;Check the Appropriate Box if a Member of a Group (See Instructions) |
|  | &nbsp;&nbsp;(a) ◻ |
|  | &nbsp;&nbsp;(b) ◻ |
| &nbsp;&nbsp;3 | &nbsp;&nbsp;SEC Use Only |
| &nbsp;&nbsp;4 | &nbsp;&nbsp; Source of Funds (See Instructions):<br> WC |
| &nbsp;&nbsp;5 | &nbsp;&nbsp; Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e):<br> ◻  |
| &nbsp;&nbsp;6 | &nbsp;&nbsp; Citizenship or Place of Organization. **United States** |
| &nbsp;&nbsp; Number<br> of Shares<br> Beneficially<br> Owned by<br> Each<br> Reporting<br> Person With | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 7 Sole Voting Power **0 shares**<br>|
| &nbsp;&nbsp; Number<br> of Shares<br> Beneficially<br> Owned by<br> Each<br> Reporting<br> Person With | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 8 Shared Voting Power **12,490,034 shares** |
| &nbsp;&nbsp; Number<br> of Shares<br> Beneficially<br> Owned by<br> Each<br> Reporting<br> Person With | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 9 Sole Dispositive Power **0 shares** |
| &nbsp;&nbsp; Number<br> of Shares<br> Beneficially<br> Owned by<br> Each<br> Reporting<br> Person With | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 10 Shared Dispositive Power **12,490,034 shares** |
| &nbsp;&nbsp;11 | &nbsp;&nbsp; Aggregate Amount Beneficially Owned by Each Reporting Person<br> **12,490,034 shares** |
| &nbsp;&nbsp;12 | &nbsp;&nbsp;Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions) ◻ |
| &nbsp;&nbsp;13 | &nbsp;&nbsp; Percent of Class Represented by Amount in Row (11)<br> **17.5%<u><sup>4</sup></u>** |
| &nbsp;&nbsp;14 | &nbsp;&nbsp;&nbsp;&nbsp; Type of Reporting Person (See Instructions)<br> **PN** |

---

<u><sup>4</sup></u> The Reporting Person is the beneficial owner of 11,081,584 shares of the Issuer's Common Stock and 2,816,900 warrants through which the Reporting Person has the right to acquire 1,408,450 Common Stock shares. The percentage calculation assumes that there are 71,518,648 outstanding shares of Common Stock of the Issuer, based on 70,058,698 outstanding shares of Common Stock of the Issuer as reported directly by the Issuer to the Reporting Persons as of March 29, 2023, and giving effect to the stock options and warrants referenced herein.

CUSIP No. 282559103

**<u>SCHEDULE 13D</u>**

**Item 1. Security and Issuer**

This Amendment No. 6 amends and supplements the statement on Schedule 13D originally filed with the Securities and Exchange Commission on November 13, 2019 as amended by Amendment No.1 filed on July 10, 2020, Amendment No.2 to filed on September 21, 2020, Amendment No. 3 filed on June 2, 2021, Amendment No. 4 filed on July 6, 2022, and Amendment No. 5 filed on October 21, 2022 (as so amended, the "Statement") by the Reporting Persons with respect to the Common Stock, $0.001 par value (the "Common Stock"), of 89bio, Inc. a Delaware corporation, which has its principal executive offices at 142 Sansome Street, Second Floor, San Francisco, CA 94104 (the "Issuer"). Unless otherwise defined herein, capitalized terms used in this Amendment No. 6 shall have the meanings ascribed to them in the Statement. Unless amended or supplemented below, the information in the Statement remains unchanged.

**Item 2. Identity and Background**

Item 2(a) of the Statement is hereby amended and restated as follows:

(a) This Statement is being filed on behalf of RA Capital Management, L.P. ("RA Capital"), RA Capital Healthcare Fund, L.P. (the "Fund"), Peter Kolchinsky, and Rajeev Shah. RA Capital, Dr. Kolchinsky, Mr. Shah, and the Fund are collectively referred to herein as the "Reporting Persons."

The Reporting Persons ownership of the Issuer's securities includes (1) 11,081,584 Common Stock shares held directly by the Fund, (2) a total of 26,306 vested stock options (right to buy), (3) 25,194 stock options (right to buy) which shall vest within 60 days of this filing, (4) a total of 2,816,900 warrants ("Warrants"), with each Warrant exercisable for one-half a share of Common Stock, through which the Fund has a right to acquire 1,408,450 Common Stock shares subject to a Beneficial Ownership Blocker detailed below, and (5) 335,364 shares held directly by the RA Capital Nexus Fund, L.P. (the "Nexus Fund"). The Warrants contain a provision (the "Beneficial Ownership Blocker") which precludes exercise of the warrants to the extent that, following exercise, the Reporting Persons, together with their affiliates and other attribution parties, would beneficially own more than 19.99% of the Ordinary Shares outstanding.

RA Capital Healthcare Fund GP, LLC is the general partner of the Fund and RA Capital Nexus Fund GP, LLC is the general partner of the Nexus Fund. The general partner of RA Capital is RA Capital Management GP, LLC, of which Dr. Kolchinsky and Mr. Shah are the controlling persons. RA Capital serves as investment adviser for the Fund and the Nexus Fund and may be deemed a beneficial owner, for purposes of Section 13(d) of the Securities Exchange Act of 1934 (the "Act"), of any securities of the Issuer held by the Fund or the Nexus Fund. The Fund and the Nexus Fund have delegated to RA Capital the sole power to vote and the sole power to dispose of all securities held in the Fund's and the Nexus Fund's portfolio, including the shares of the Issuer's Common Stock reported herein. Because the Fund and the Nexus Fund have divested themselves of voting and investment power over the reported securities they hold and may not revoke that delegation on less than 61 days' notice, the Fund and the Nexus Fund disclaim beneficial ownership of the securities they hold for purposes of Section 13(d) of the Act and therefore disclaim any obligation to report ownership of the reported securities under Section 13(d) of the Act. As managers of RA Capital, Dr. Kolchinsky and Mr. Shah may be deemed beneficial owners, for purposes of Section 13(d) of the Act, of any securities of the Issuer beneficially owned by RA Capital. RA Capital, Dr. Kolchinsky, and Mr. Shah disclaim beneficial ownership of the securities reported in this 13D/A other than for the purpose of determining their obligations under Section 13(d) of the Act, and the filing of the Statement shall not be deemed an admission that either RA Capital, Dr. Kolchinsky, or Mr. Shah is the beneficial owner of such securities for any other purpose.

CUSIP No. 282559103

(b) The address of the principal business office of each of the Reporting Persons is 200 Berkeley Street, 18th Floor, Boston, MA 02116.

(c) The Fund is a private investment vehicle. RA Capital provides investment management services to the Fund and the Nexus Fund. The principal occupation of Dr. Kolchinsky and Mr. Shah is investment management.

(d) During the last five years, none of the Reporting Persons has been convicted in a criminal proceeding (excluding traffic violations or similar misdemeanors).

(e) During the last five years, none of the Reporting Persons has been 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 of 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.

(f) See Item 6 of the cover pages.

**Item 3. Source and Amount of Funds or Other Consideration**

Item 3 of the Statement is hereby amended and supplemented as follows:

The Reporting Persons acquired additional securities of the Issuer in the transactions described in Item 5(c) of this Amendment No. 6 pursuant to the Issuer's public offering described in the Issuer's Prospectus filed with the Securities and Exchange Commission filed on March 27, 2023, for an aggregate of $39,999,992.50. The purchase was for cash and was funded by the working capital of the Fund.

**Item 5. Interest in Securities of the Issuer**

Item 5 of the Statement is hereby amended and supplemented as follows:

(a) and (b) See Items 7-11 of the cover pages above and Item 2.

(c) The following table lists the Reporting Persons' transactions in Common Stock that were effected during the sixty day period prior to the filing of this Schedule 13D:

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Transaction** | **Purchaser** | **Date** | **No. Shares** | **Price** |
| Purchase | The Fund | 24-Mar-2023 | 2461538 | $16.25 |
| Vest Stock Option (Right to Buy) | RA Capital | 5-Feb-2023 | 194.5 | (1) |
| Vest Stock Option (Right to Buy) | RA Capital | 5-Mar-2023 | 194.5 | (1) |
| Vest Stock Option (Right to Buy) | RA Capital | 5-April-2023 | 194 | (1) |
| Vest Stock Option (Right to Buy) | RA Capital | 16-May-2023 | 25000 | (2) |

---

&nbsp;&nbsp;&nbsp;&nbsp;(1) This option represents a right to purchase a total of 7,000 shares of the Issuer's Common Stock, one third of which vested on April 5,
2021, with the remaining two thirds vesting in equal monthly installments over the following two years, subject to Dr. DiRocco's
continued service to the Issuer through each vesting date. These options have an exercise price of $21.40.

&nbsp;&nbsp;&nbsp;&nbsp;(2) This option represents a right to purchase a total of 25,000 shares of the Issuer's Common Stock, which will vest in full on May
16, 2023. These options have an exercise price of $2.64.

\* Represents future vesting within 60 days from the filing date of this Form 13D/A.

CUSIP No. 282559103

(d) Not applicable.

(e) Not applicable.

**Item 7. Material to Be Filed as Exhibits**

Item 7 of the Statement is amended and supplemented by the following:

Exhibit 1 Joint Filing Agreement

CUSIP No. 282559103

**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.

Date: March 30, 2023

---

| | | |
|:---|:---|:---|
| RA CAPITAL MANAGEMENT, L.P. | RA CAPITAL MANAGEMENT, L.P. | RA CAPITAL MANAGEMENT, L.P. |
| By: | /s/ Peter Kolchinsky | /s/ Peter Kolchinsky |
|  | Name: | Peter Kolchinsky |
|  | Title: | Authorized Signatory |
| PETER KOLCHINSKY | PETER KOLCHINSKY | PETER KOLCHINSKY |
| /s/ Peter Kolchinsky | /s/ Peter Kolchinsky | /s/ Peter Kolchinsky |
| RAJEEV SHAH | RAJEEV SHAH | RAJEEV SHAH |
| /s/ Rajeev Shah | /s/ Rajeev Shah | /s/ Rajeev Shah |
| RA CAPITAL HEALTHCARE FUND, L.P. | RA CAPITAL HEALTHCARE FUND, L.P. | RA CAPITAL HEALTHCARE FUND, L.P. |
| By: | RA Capital Healthcare Fund GP, LLC | RA Capital Healthcare Fund GP, LLC |
| Its: | General Partner | General Partner |
| By: | /s/ Peter Kolchinsky | /s/ Peter Kolchinsky |
|  | Name: | Peter Kolchinsky |
|  | Title: | Manager |

---

CUSIP No. 282559103

**JOINT FILING AGREEMENT**

This Joint Filing Agreement, dated as of March 30, 2023, is by and among RA Capital Management, L.P., Peter Kolchinsky, Rajeev Shah, and RA Capital Healthcare Fund, L.P. (the foregoing are collectively referred to herein as the "Filers").

Each of the Filers may be required to file with the United States Securities and Exchange Commission a statement on Schedule 13G and/or 13D with respect to Common Stock, par value $0.001 per share of 89bio, Inc. beneficially owned by them from time to time.

Pursuant to and in accordance with Rule 13(d)(1)(k) promulgated under the Securities Exchange Act of 1934, as amended, the Filers hereby agree to file a single statement on Schedule 13G and/or 13D (and any amendments thereto) on behalf of each of such parties, and hereby further agree to file this Joint Filing Agreement as an exhibit to such statement, as required by such rule.

This Joint Filing Agreement may be terminated by any of the Filers upon one week's prior written notice or such lesser period of notice as the Filers may mutually agree.

Executed and delivered as of the date first above written.

---

| | | |
|:---|:---|:---|
| RA CAPITAL MANAGEMENT, L.P. | RA CAPITAL MANAGEMENT, L.P. | RA CAPITAL MANAGEMENT, L.P. |
| By: | /s/ Peter Kolchinsky | /s/ Peter Kolchinsky |
|  | Name: | Peter Kolchinsky |
|  | Title: | Authorized Signatory |
| PETER KOLCHINSKY | PETER KOLCHINSKY | PETER KOLCHINSKY |
| /s/ Peter Kolchinsky | /s/ Peter Kolchinsky | /s/ Peter Kolchinsky |
| RAJEEV SHAH | RAJEEV SHAH | RAJEEV SHAH |
| /s/ Rajeev Shah | /s/ Rajeev Shah | /s/ Rajeev Shah |

---

---

| | | |
|:---|:---|:---|
| RA CAPITAL HEALTHCARE FUND, L.P. | RA CAPITAL HEALTHCARE FUND, L.P. | RA CAPITAL HEALTHCARE FUND, L.P. |
| By: | RA Capital Healthcare Fund GP, LLC | RA Capital Healthcare Fund GP, LLC |
| Its: | General Partner | General Partner |
| By: | /s/ Peter Kolchinsky | /s/ Peter Kolchinsky |
|  | Name: | Peter Kolchinsky |
|  | Title: | Manager |

---