Common Shares

ESSA Pharma Inc.

SUITE 720, VANCOUVER, A1, V5Z 1K5

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.

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.