# EDGAR Filing Document

**Accession Number:** 0000918923
**File Stem:** 0000921895-25-002132
**Filing Date:** 2025-8
**Character Count:** 35005
**Document Hash:** f5bbabcbd1885ab5357de3a5c0f7b780
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0000921895-25-002132.hdr.sgml**: 20250807

**ACCESSION NUMBER**: 0000921895-25-002132

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

**PUBLIC DOCUMENT COUNT**: 2

**FILED AS OF DATE**: 20250807

**DATE AS OF CHANGE**: 20250807

**SUBJECT COMPANY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** ESSA Pharma Inc.
- **CENTRAL INDEX KEY:** 0001633932
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 000000000
- **STATE OF INCORPORATION:** A1
- **FISCAL YEAR END:** 0930

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13D/A
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 005-88939
- **FILM NUMBER:** 251194674

**BUSINESS ADDRESS:**
- **STREET 1:** SUITE 720
- **STREET 2:** 999 WEST BROADWAY
- **CITY:** VANCOUVER
- **STATE:** A1
- **ZIP:** V5Z 1K5
- **BUSINESS PHONE:** (778) 331-0962

**MAIL ADDRESS:**
- **STREET 1:** SUITE 720
- **STREET 2:** 999 WEST BROADWAY
- **CITY:** VANCOUVER
- **STATE:** A1
- **ZIP:** V5Z 1K5
**FILED BY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** BIOTECHNOLOGY VALUE FUND L P
- **CENTRAL INDEX KEY:** 0000918923
- **STANDARD INDUSTRIAL CLASSIFICATION:** INVESTMENT ADVICE [6282]
- **ORGANIZATION NAME:** 02 Finance
- **EIN:** 363924731
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

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

**BUSINESS ADDRESS:**
- **STREET 1:** 44 MONTGOMERY STREET
- **STREET 2:** 40TH FL
- **CITY:** SAN FRANCISCO
- **STATE:** CA
- **ZIP:** 94104
- **BUSINESS PHONE:** 3125066500

**MAIL ADDRESS:**
- **STREET 1:** 44 MONTGOMERY STREET
- **STREET 2:** 40TH FL
- **CITY:** SAN FRANCISCO
- **STATE:** CA
- **ZIP:** 94104

## Exhibit 99.1

Exhibit 99.1

**WAIVER AND AGREEMENT TO EXERCISE**

---

| | |
|:---|:---|
| &nbsp;&nbsp;**RE:** | &nbsp;&nbsp;The amended and restated common share purchase warrant of ESSA Pharma Inc. (the "**Company**") dated August 27, 2019, as amended and restated on August 14, 2024 and issued in the name of ("**BVF LP**"), the amended and restated common share purchase warrant of the Company dated August 27, 2019, as amended and restated on August 14, 2024 and issued in the name of Biotechnology Value Fund II, LP ("**BVF II**"), the amended and restated common share purchase warrant of the Company dated August 27, 2019, as amended and restated on August 14, 2024 and issued in the name of Biotechnology Value Trading Fund OS, L.P. ("**BVF OS**") (together with BVF LP, BVF II and BVF OS, "**BVF**") (collectively, the "**Warrants**") |
| &nbsp;&nbsp;**DATE:** | &nbsp;&nbsp;August 5, 2025 |

---

**WHEREAS** section 2(e) of each of the Warrants provides that the Company shall not effect any exercise of the Warrants if BVF would, in the aggregate, beneficially own common shares of the Company in excess of the Beneficial Ownership Limitation (as defined in the Warrants) and that in no event shall the Beneficial Ownership Limitation exceed 19.99%;

**AND WHEREAS** BVF wishes to exercise the Warrants, which exercise would result in BVF exceeding the maximum Beneficial Ownership Limitation of 19.99%; and

**AND WHEREAS** the Company and BVF wish to waive the Beneficial Ownership Limitation in order to permit the complete exercise of the Warrants by BVF.

**NOW THEREFORE** for good and valuable consideration, the receipt and sufficiency of which is hereby acknowledged, BVF and the Company agree as follows:

1. The Company and BVF hereby agree to waive section 2(e) of the Warrants in respect of the Beneficial Ownership
Limitation to permit the full exercise of the Warrants by BVF. For greater certainty, this waiver is given only in respect of section
2(e) as it applies to the Beneficial Ownership Limitation and all other terms of the Warrant shall otherwise continue in full force and
effect.

2. BVF hereby agrees that it will fully exercise all, but not less than all, of the Warrants effective as
of the date hereof by delivering to the Company a duly completed and executed notice of exercise in respect of each of the Warrants in
the form attached as Exhibit "A" to the Warrants together with any required payment therefor (and for greater certainty, if
BVF for any reason fails to do so, then BVF shall, by its signatures below, be deemed to have exercised the Warrants as of the date hereof).

3. This Waiver and Agreement to Exercise shall be governed by and construed in accordance with the laws of
the Province of British Columbia and the laws of Canada applicable therein.

4. This Waiver and Agreement to Exercise may be executed in any number of counterparts and all such counterparts
taken together shall be deemed to constitute one and the same instrument.

---

| | | | |
|:---|:---|:---|:---|
| DATED as of the date first written above. | DATED as of the date first written above. | | |
| **BIOTECHNOLOGY VALUE FUND, L.P.,** | **BIOTECHNOLOGY VALUE FUND, L.P.,** | **BIOTECHNOLOGY VALUE FUND II, L.P.,** | **BIOTECHNOLOGY VALUE FUND II, L.P.,** |
| Per: | /s/ Mark Lampert | Per: | /s/ Mark Lampert |
| Name: | Mark Lampert | Name: | Mark Lampert |
| Title: | Chief Executive Officer BVF I GP LLC, itself General Partner of Biotechnology Value Fund, L.P. | Title: | Chief Executive Officer BVF II GP LLC, itself General Partner of Biotechnology Value Fund II, L.P. |

---

---

| | | | |
|:---|:---|:---|:---|
| **BIOTECHNOLOGY VALUE TRADING**<br> **FUND OS LP,** | **BIOTECHNOLOGY VALUE TRADING**<br> **FUND OS LP,** | **ESSA PHARMA INC.** | **ESSA PHARMA INC.** |
| Per: | /s/ Mark Lampert | Per: | /s/ David Wood |
| Name: | Mark Lampert | Name: | David Wood |
| Title: | President BVF Inc., General Partner of BVF Partners L.P., itself sole member of BVF Partners OS Ltd., itself GP of Biotechnology Value Trading Fund OS LP | Title: | Chief Financial Officer |

---

### UNITED STATES SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## SCHEDULE 13D

### Under the Securities Exchange Act of 1934

**(Amendment No. 1)**

**ESSA Pharma Inc.**

*(Name of Issuer)*

**Common Shares**

*(Title of Class of Securities)*

**29668H708**

*(CUSIP Number)*

**JAMES KRATKY**<br>BVF PARTNERS L.P.<br>44 Montgomery St., 40th Floor<br>San Francisco CA 94104<br>415-525-8800

*(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)*

**08/05/2025**

*(Date of Event Which Requires Filing of this Statement)*

| **CUSIP No.** | **29668H708** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**BIOTECHNOLOGY VALUE FUND L P** | Name of reporting person<br>**BIOTECHNOLOGY VALUE FUND L P** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**WC** | Source of funds (See Instructions)<br>**WC** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**DELAWARE** | Citizenship or place of organization<br>**DELAWARE** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**6194145.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**6194145.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**6194145.00** | Aggregate amount beneficially owned by each reporting person<br>**6194145.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**13.1%** | Percent of class represented by amount in Row (11)<br>**13.1%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**PN** | Type of Reporting Person (See Instructions)<br>**PN** | |

---

| **CUSIP No.** | **29668H708** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**BVF I GP LLC** | Name of reporting person<br>**BVF I GP LLC** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**AF** | Source of funds (See Instructions)<br>**AF** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**DELAWARE** | Citizenship or place of organization<br>**DELAWARE** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**6194145.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**6194145.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**6194145.00** | Aggregate amount beneficially owned by each reporting person<br>**6194145.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**13.1%** | Percent of class represented by amount in Row (11)<br>**13.1%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**OO** | Type of Reporting Person (See Instructions)<br>**OO** | |

---

| **CUSIP No.** | **29668H708** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**BIOTECHNOLOGY VALUE FUND II LP** | Name of reporting person<br>**BIOTECHNOLOGY VALUE FUND II LP** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**WC** | Source of funds (See Instructions)<br>**WC** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**DELAWARE** | Citizenship or place of organization<br>**DELAWARE** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**4726743.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**4726743.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**4726743.00** | Aggregate amount beneficially owned by each reporting person<br>**4726743.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**9.99%** | Percent of class represented by amount in Row (11)<br>**9.99%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**PN** | Type of Reporting Person (See Instructions)<br>**PN** | |

---

| **CUSIP No.** | **29668H708** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**BVF II GP LLC** | Name of reporting person<br>**BVF II GP LLC** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**AF** | Source of funds (See Instructions)<br>**AF** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**DELAWARE** | Citizenship or place of organization<br>**DELAWARE** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**4726743.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**4726743.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**4726743.00** | Aggregate amount beneficially owned by each reporting person<br>**4726743.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**9.99%** | Percent of class represented by amount in Row (11)<br>**9.99%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**OO** | Type of Reporting Person (See Instructions)<br>**OO** | |

---

| **CUSIP No.** | **29668H708** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**Biotechnology Value Trading Fund OS LP** | Name of reporting person<br>**Biotechnology Value Trading Fund OS LP** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**WC** | Source of funds (See Instructions)<br>**WC** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**CAYMAN ISLANDS** | Citizenship or place of organization<br>**CAYMAN ISLANDS** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**560797.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**560797.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**560797.00** | Aggregate amount beneficially owned by each reporting person<br>**560797.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**1.2%** | Percent of class represented by amount in Row (11)<br>**1.2%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**PN** | Type of Reporting Person (See Instructions)<br>**PN** | |

---

| **CUSIP No.** | **29668H708** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**BVF Partners OS Ltd.** | Name of reporting person<br>**BVF Partners OS Ltd.** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**AF** | Source of funds (See Instructions)<br>**AF** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**CAYMAN ISLANDS** | Citizenship or place of organization<br>**CAYMAN ISLANDS** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**560797.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**560797.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**560797.00** | Aggregate amount beneficially owned by each reporting person<br>**560797.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**1.2%** | Percent of class represented by amount in Row (11)<br>**1.2%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**CO** | Type of Reporting Person (See Instructions)<br>**CO** | |

---

| **CUSIP No.** | **29668H708** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**BVF GP HOLDINGS LLC** | Name of reporting person<br>**BVF GP HOLDINGS LLC** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**AF** | Source of funds (See Instructions)<br>**AF** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**DELAWARE** | Citizenship or place of organization<br>**DELAWARE** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**10920888.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**10920888.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**10920888.00** | Aggregate amount beneficially owned by each reporting person<br>**10920888.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**23.1%** | Percent of class represented by amount in Row (11)<br>**23.1%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**OO** | Type of Reporting Person (See Instructions)<br>**OO** | |

---

| **CUSIP No.** | **29668H708** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**BVF PARTNERS L P/IL** | Name of reporting person<br>**BVF PARTNERS L P/IL** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**AF** | Source of funds (See Instructions)<br>**AF** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**DELAWARE** | Citizenship or place of organization<br>**DELAWARE** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**11668473.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**11668473.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**11668473.00** | Aggregate amount beneficially owned by each reporting person<br>**11668473.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**24.7%** | Percent of class represented by amount in Row (11)<br>**24.7%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**IA** | Type of Reporting Person (See Instructions)<br>**IA** | |

---

| **CUSIP No.** | **29668H708** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**BVF INC/IL** | Name of reporting person<br>**BVF INC/IL** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**AF** | Source of funds (See Instructions)<br>**AF** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**DELAWARE** | Citizenship or place of organization<br>**DELAWARE** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**11668473.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**11668473.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**11668473.00** | Aggregate amount beneficially owned by each reporting person<br>**11668473.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**24.7%** | Percent of class represented by amount in Row (11)<br>**24.7%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**CO** | Type of Reporting Person (See Instructions)<br>**CO** | |

---

| **CUSIP No.** | **29668H708** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**LAMPERT MARK N** | Name of reporting person<br>**LAMPERT MARK N** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**AF** | Source of funds (See Instructions)<br>**AF** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**X1** | Citizenship or place of organization<br>**X1** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**11668473.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**11668473.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**11668473.00** | Aggregate amount beneficially owned by each reporting person<br>**11668473.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**24.7%** | Percent of class represented by amount in Row (11)<br>**24.7%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**IN** | Type of Reporting Person (See Instructions)<br>**IN** | |

---

**Item 1. Security and Issuer**

**(a) Title of Class of Securities:**
Common Shares

**(b) Name of Issuer:**
ESSA Pharma Inc.

**(c) Address of Issuer's Principal Executive Offices:**
SUITE 720, 999 WEST BROADWAY, VANCOUVER, A1, V5Z 1K5

**Item 4. Purpose of Transaction**

Item 4 is hereby amended to add the following:

On August 5, 2025, certain of the Reporting Persons including BVF, BVF2 and Trading Fund OS entered into a waiver and agreement to exercise (the "Waiver and Agreement") with the Issuer with respect to the amended and restated common share purchase warrants (the "Pre-Funded Warrants") held by them in connection with the Issuer's proposed upcoming merger. Pursuant to the Waiver and Agreement, (i) BVF, BVF2, Trading Fund OS and the Issuer agreed to waive the 19.99% beneficial ownership limitation set forth in Section 2(e) of the Pre-Funded Warrants to permit the full exercise of the of the Pre-Funded Warrants held by them, and (ii) BVF, BVF2 and Trading Fund OS exercised all of the Pre-Funded Warrants held by them in a cashless exercise to acquire 1,481,555 Shares, 1,234,964 Shares and 203,325 Shares, respectively, effective August 5, 2025 (the "Exercise"). A copy of the Waiver and Agreement is attached hereto as Exhibit 99.1 and is incorporated herein by reference.

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

**(a)**
Item 5(a) is hereby amended and restated to read as follows:

The aggregate percentage of Shares reported owned by each person named herein is based upon a denominator that is the sum of (i) 44,388,550 Shares outstanding, which is the total number of Shares expected to be outstanding as of August 5, 2025 as reported in the Issuer's Preliminary Proxy Statement on Schedule 14A filed with the Securities and Exchange Commission on July 30, 2025, and (ii) 2,919,844 Shares acquired by certain of the Reporting Persons in connection with the cashless exercise of the Pre-Funded Warrants described in further detail in Item 4 above.

As of the date hereof, (i) BVF beneficially owned 6,194,145 Shares, representing percentage ownership of approximately 13.1% of the Shares outstanding, (ii) BVF2 beneficially owned 4,726,743 Shares, representing percentage ownership of approximately 9.99% of the Shares outstanding, (iii) Trading Fund OS beneficially owned 560,797 Shares, representing percentage ownership of approximately 1.2% of the Shares outstanding, and (iv) 186,788 Shares were held in the Partners Managed Account, representing percentage ownership of less than 1% of the Shares outstanding.

BVF GP, as the general partner of BVF, may be deemed to beneficially own the 6,194,145 Shares beneficially owned by BVF, representing percentage ownership of approximately 13.1% of the Shares outstanding.

BVF2 GP, as the general partner of BVF2, may be deemed to beneficially own the 4,726,743 Shares beneficially owned by BVF2, representing percentage ownership of approximately 9.99% of the Shares outstanding.

Partners OS, as the general partner of Trading Fund OS, may be deemed to beneficially own the 560,797 Shares beneficially owned by Trading Fund OS, representing percentage ownership of approximately 1.2% of the Shares outstanding.

BVF GPH, as the sole member of each of BVF GP and BVF2 GP, may be deemed to beneficially own the 10,920,888 Shares beneficially owned in the aggregate by BVF and BVF2, representing percentage ownership of approximately 23.1% of the Shares outstanding.

Partners, as the investment manager of BVF, BVF2, Trading Fund OS and the Partners Managed Account and the sole member of Partners OS, may be deemed to beneficially own the 11,668,473 Shares beneficially owned in the aggregate by BVF, BVF2, Trading Fund OS, and held in the Partners Managed Account, representing percentage ownership of approximately 24.7% of the Shares outstanding.

BVF Inc., as the general partner of Partners, may be deemed to beneficially own the 11,668,473 Shares beneficially owned by Partners, representing percentage ownership of approximately 24.7% of the Shares outstanding.

Mr. Lampert, as the sole director and officer of BVF Inc., may be deemed to beneficially own the 11,668,473 Shares beneficially owned by BVF Inc., representing percentage ownership of approximately 24.7% of the Shares outstanding.

The foregoing should not be construed in and of itself as an admission by any Reporting Person as to beneficial ownership of any Shares owned by another Reporting Person. BVF GP disclaims beneficial ownership of the Shares beneficially owned by BVF. BVF2 GP disclaims beneficial ownership of the Shares beneficially owned by BVF2. Partners OS disclaims beneficial ownership of the Shares beneficially owned by Trading Fund OS. BVF GPH disclaims beneficial ownership of the Shares beneficially owned by BVF and BVF2. Each of Partners, BVF Inc. and Mr. Lampert disclaims beneficial ownership of the Shares beneficially owned by BVF, BVF2 and Trading Fund OS and held in the Partners Managed Account.

**(b)**
—

**(c)**
Item 5(c) is hereby amended and restated to read as follows:

Other than as set forth in Item 4 above and in the immediately following sentence, there were no transactions in the securities of the Issuer by the Reporting Persons during the past sixty days. In connection with the Exercise, BVF, BVF2 and Trading Fund OS disposed of 70, 66, and 11 Shares to the Issuer, respectively, based on a market price of $1.8779 per Share.

**Item 6. Contracts, Arrangements, Understandings or Relationships With Respect to Securities of the Issuer.**

Item 6 is hereby amended to add the following:

On August 5, 2025, BVF, BVF2 and Trading Fund OS entered into the Waiver and Agreement with the Issuer as described in Item 4 above. A copy of the Waiver and Agreement is attached hereto as Exhibit 99.1 and is incorporated herein by reference.

### 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.

**Reporting Person:** BIOTECHNOLOGY VALUE FUND L P

**Signature:** /s/ Mark N. Lampert

**Name/Title:** Mark N. Lampert, Authorized Signatory

**Date:** 08/07/2025

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.

**Reporting Person:** BVF I GP LLC

**Signature:** /s/ Mark N. Lampert

**Name/Title:** Mark N. Lampert, Authorized Signatory

**Date:** 08/07/2025

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.

**Reporting Person:** BIOTECHNOLOGY VALUE FUND II LP

**Signature:** /s/ Mark N. Lampert

**Name/Title:** Mark N. Lampert, Authorized Signatory

**Date:** 08/07/2025

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.

**Reporting Person:** BVF II GP LLC

**Signature:** /s/ Mark N. Lampert

**Name/Title:** Mark N. Lampert, Authorized Signatory

**Date:** 08/07/2025

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.

**Reporting Person:** Biotechnology Value Trading Fund OS LP

**Signature:** /s/ Mark N. Lampert

**Name/Title:** Mark N. Lampert, Authorized Signatory

**Date:** 08/07/2025

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.

**Reporting Person:** BVF Partners OS Ltd.

**Signature:** /s/ Mark N. Lampert

**Name/Title:** Mark N. Lampert, Authorized Signatory

**Date:** 08/07/2025

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.

**Reporting Person:** BVF GP HOLDINGS LLC

**Signature:** /s/ Mark N. Lampert

**Name/Title:** Mark N. Lampert, Authorized Signatory

**Date:** 08/07/2025

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.

**Reporting Person:** BVF PARTNERS L P/IL

**Signature:** /s/ Mark N. Lampert

**Name/Title:** Mark N. Lampert, Authorized Signatory

**Date:** 08/07/2025

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.

**Reporting Person:** BVF INC/IL

**Signature:** /s/ Mark N. Lampert

**Name/Title:** Mark N. Lampert, Authorized Signatory

**Date:** 08/07/2025

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.

**Reporting Person:** LAMPERT MARK N

**Signature:** /s/ Mark N. Lampert

**Name/Title:** Mark N. Lampert

**Date:** 08/07/2025