[Form 4] ESSA Pharma Inc. Insider Trading Activity

Rhea-AI Filing Summary

ESSA Pharma Inc. (EPIX) insiders affiliated with Biotechnology Value Fund entities reported share dispositions tied to the company’s merger. On 10/09/2025, the transaction was coded “U,” indicating a corporate action. Reported lines show dispositions of 6,194,145 shares, 4,726,743 shares, and 560,797 shares, with 0 shares beneficially owned afterward for each line.

Per the terms, holders received $0.124231 in cash per share and one contingent value right (CVR) per share for potential cash payments of up to approximately $0.14 per share; this excludes approximately $1.69 per share previously distributed. The filing notes the arrangement under British Columbia law and identifies XenoTherapeutics, Inc. as the parent entity in the acquisition structure.

Insights

M&A and Securities Disclosure Analyst

Form 4 confirms merger close and consideration mechanics.

The report records dispositions via code U on 10/09/2025, consistent with a closing under a court-approved plan of arrangement. The consideration includes $0.124231 per share in cash plus one CVR per share with potential payments up to approximately $0.14 per share, excluding about $1.69 previously distributed.

The BVF-affiliated filers show 0 shares beneficially owned after the transactions, indicating their positions were extinguished in the merger. Actual CVR payouts, if any, would depend on defined milestones; the excerpt lists the potential amount but not the triggers.

SEC Form 4

FORM 4

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

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

X

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person^*

BVF PARTNERS L P/IL

(Last) (First) (Middle)

44 MONTGOMERY ST.

40TH FLOOR

(Street)

SAN FRANCISCO CA 94104

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
ESSA Pharma Inc. [ EPIX ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
10/09/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

	Form filed by One Reporting Person
X	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock(1)	10/09/2025		U(2)		6,194,145	D	(6)	0	D(3)
Common Stock(1)	10/09/2025		U(2)		4,726,743	D	(6)	0	D(4)
Common Stock(1)	10/09/2025		U(2)		560,797	D	(6)	0	D(5)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

1. Name and Address of Reporting Person^*

BVF PARTNERS L P/IL

(Last) (First) (Middle)

44 MONTGOMERY ST.

40TH FLOOR

(Street)

SAN FRANCISCO CA 94104

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

BIOTECHNOLOGY VALUE FUND L P

(Last) (First) (Middle)

44 MONTGOMERY ST.

40TH FLOOR

(Street)

SAN FRANCISCO CA 94104

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

BVF I GP LLC

(Last) (First) (Middle)

44 MONTGOMERY ST.

40TH FLOOR

(Street)

SAN FRANCISCO CA 94104

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

BIOTECHNOLOGY VALUE FUND II LP

(Last) (First) (Middle)

44 MONTGOMERY ST.

40TH FLOOR

(Street)

SAN FRANCISCO CA 94104

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director		10% Owner
	Officer (give title below)	X	Other (specify below)
			See Explanation of Responses

1. Name and Address of Reporting Person^*

BVF II GP LLC

(Last) (First) (Middle)

44 MONTGOMERY ST.

40TH FLOOR

(Street)

SAN FRANCISCO CA 94104

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director		10% Owner
	Officer (give title below)	X	Other (specify below)
			See Explanation of Responses

1. Name and Address of Reporting Person^*

Biotechnology Value Trading Fund OS LP

(Last) (First) (Middle)

P.O. BOX 309 UGLAND HOUSE

(Street)

GRAND CAYMAN E9 KY1-1104

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director		10% Owner
	Officer (give title below)	X	Other (specify below)
			See Explanation of Responses

1. Name and Address of Reporting Person^*

BVF Partners OS Ltd.

(Last) (First) (Middle)

P.O. BOX 309 UGLAND HOUSE

(Street)

GRAND CAYMAN E9 KY1-1104

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director		10% Owner
	Officer (give title below)	X	Other (specify below)
			See Explanation of Responses

1. Name and Address of Reporting Person^*

BVF GP HOLDINGS LLC

(Last) (First) (Middle)

44 MONTGOMERY ST.

40TH FLOOR

(Street)

SAN FRANCISCO CA 94104

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

BVF INC/IL

(Last) (First) (Middle)

44 MONTGOMERY ST.

40TH FLOOR

(Street)

SAN FRANCISCO CA 94104

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

LAMPERT MARK N

(Last) (First) (Middle)

44 MONTGOMERY ST.

40TH FLOOR

(Street)

SAN FRANCISCO CA 94104

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

Explanation of Responses:

1. This Form 4 is filed jointly by Biotechnology Value Fund, L.P. ("BVF"), Biotechnology Value Fund II, L.P. ("BVF2"), Biotechnology Value Trading Fund OS LP ("Trading Fund OS"), BVF Partners OS Ltd. ("Partners OS"), BVF I GP LLC ("BVF GP"), BVF II GP LLC ("BVF2 GP"), BVF GP Holdings LLC ("BVF GPH"), BVF Partners L.P. ("Partners"), BVF Inc. and Mark N. Lampert (collectively, the "Reporting Persons"). Each of the Reporting Persons is a member of a Section 13(d) group. Each of the Reporting Persons disclaims beneficial ownership of the securities reported herein except to the extent of his or its pecuniary interest therein.

2. This Form 4 reports securities disposed of pursuant to an arrangement under Section 288 of the Business Corporations Act (British Columbia) involving the Issuer, XenoTherapeutics, Inc. (the "Parent"), Xeno Acquisition Corp. (the "Purchaser"), a wholly-owned subsidiary of Parent, and XOMA Royalty Corporation pursuant to a business combination agreement dated July 13, 2025, and the plan of arrangement, pursuant to which, among other things, the Purchaser acquired all of the outstanding shares of common stock of the Issuer, effective October 9, 2025 (the "Merger").

3. Securities owned directly by BVF. As the general partner of BVF, BVF GP may be deemed to beneficially own the securities owned directly by BVF. As the sole member of BVF GP, BVF GPH may be deemed to beneficially own the securities owned directly by BVF. As the investment manager of BVF, Partners may be deemed to beneficially own the securities owned directly by BVF. As the investment adviser and general partner of Partners, BVF Inc. may be deemed to beneficially own the securities owned directly by BVF. As a director and officer of BVF Inc., Mr. Lampert may be deemed to beneficially own the securities owned directly by BVF.

4. Securities owned directly by BVF2. As the general partner of BVF2, BVF2 GP may be deemed to beneficially own the securities owned directly by BVF2. As the sole member of BVF2 GP, BVF GPH may be deemed to beneficially own the securities owned directly by BVF2. As the investment manager of BVF2, Partners may be deemed to beneficially own the securities owned directly by BVF2. As the investment adviser and general partner of Partners, BVF Inc. may be deemed to beneficially own the securities owned directly by BVF2. As a director and officer of BVF Inc., Mr. Lampert may be deemed to beneficially own the securities owned directly by BVF2.

5. Securities owned directly by Trading Fund OS. As the general partner of Trading Fund OS, Partners OS may be deemed to beneficially own the securities owned directly by Trading Fund OS. As the investment manager of Trading Fund OS and the sole member of Partners OS, Partners may be deemed to beneficially own the securities owned directly by Trading Fund OS. As the investment adviser and general partner of Partners, BVF Inc. may be deemed to beneficially own the securities owned directly by Trading Fund OS. As a director and officer of BVF Inc., Mr. Lampert may be deemed to beneficially own the securities owned directly by Trading Fund OS.

6. The Reporting Persons received the following in exchange for each share of the Issuer's common stock disposed of in connection with the Merger: $0.124231 in cash per share of common stock (excluding the approximately $1.69 of cash per share of common stock previously distributed to the Issuer's shareholders) and one contingent value right per share of common stock for potential cash payments of up to approximately $0.14 per share of common stock.

	BVF Partners L.P., By: BVF Inc., its general partner, By: /s/ Mark N. Lampert, President	10/14/2025
	Biotechnology Value Fund, L.P., By: BVF I GP LLC, its general partner, By: /s/ Mark N. Lampert, Chief Executive Officer	10/14/2025
	BVF I GP LLC, By: /s/ Mark N. Lampert, Chief Executive Officer	10/14/2025
	Biotechnology Value Fund II, L.P., By: BVF II GP LLC, its general partner, By: /s/ Mark N. Lampert, Chief Executive Officer	10/14/2025
	BVF II GP LLC, By: /s/ Mark N. Lampert, Chief Executive Officer	10/14/2025
	BVF Partners OS Ltd., By: BVF Partners L.P., its sole member, By: BVF Inc., its general partner, By: /s/ Mark N. Lampert, President	10/14/2025
	Biotechnology Value Trading Fund OS LP, By: BVF Partners L.P., its investment manager, BVF Inc., its general partner, By: /s/ Mark N. Lampert, President	10/14/2025
	BVF GP Holdings LLC, By: /s/ Mark N. Lampert, Chief Executive Officer	10/14/2025
	BVF Inc., By: /s/ Mark N. Lampert, President	10/14/2025
	/s/ Mark N. Lampert	10/14/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What did ESSA Pharma (EPIX) shareholders receive in the merger?

Holders received $0.124231 per share in cash and one CVR per share for potential payments of up to approximately $0.14 per share, excluding about $1.69 previously distributed.

When was the transaction effective for ESSA Pharma (EPIX)?

The transaction date reported is 10/09/2025 with transaction code U (corporate action).

How many shares did BVF-affiliated entities report disposing of?

Reported dispositions include 6,194,145, 4,726,743, and 560,797 shares across lines in Table I.

How many ESSA Pharma shares did the reporting persons own after the merger?

Each reported line shows 0 shares beneficially owned following the transaction.

Who acquired ESSA Pharma under the arrangement?

The arrangement identifies XenoTherapeutics, Inc. as the parent, with Xeno Acquisition Corp. as purchaser.

What legal framework governed the transaction?

It was completed under Section 288 of the British Columbia Business Corporations Act via a plan of arrangement.