ATHE 6-K 2025 - Equibles

SECURITIESAND EXCHANGE COMMISSION

Washington,D.C. 20549

FORM6-K

REPORTOF FOREIGN PRIVATE ISSUER

PURSUANTTO RULE 13a-16 OR 15d-163

UNDERTHE SECURITIES EXCHANGE ACT OF 1934

Forthe month of September 2025

AlterityTherapeutics Limited

(Name of Registrant)

Level 14, 350 Collins Street,Melbourne, Victoria 3000 Australia

(Address of Principal Executive Office)

Indicateby check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.

Form 20-F ☒ Form 40-F ☐

ThisForm 6-K is being incorporated by reference into our Registration Statement on Form S-8 (Files No. 333-251073,333-248980 and 333-228671)and our Registration Statements on Form F-3 (Files No. 333-274816,333-251647, 333-231417and 333-250076)

ALTERITYTHERAPEUTICS LIMITED

(adevelopment stage enterprise)

The following exhibits are submitted:

99.1	Change of Director's Interest Notice x 4

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

Alterity Therapeutics Limited
By:	/s/ Geoffrey P. Kempler
	Geoffrey P. Kempler
	Chairman

Date: September 17, 2025

Exhibit 99.1

Appendix 3Y
Change of Director’s Interest Notice

Rule 3.19A.2

Appendix 3Y

Change of Director’s Interest Notice

Informationor documents not available now must be given to ASX as soon as available. Information and documents given to ASX becomes ASX*’sproperty and may be made public.*

Introduced 30/09/01 Amended 01/01/11

Name of entity	Alterity Therapeutics Limited
ABN	37 080 699 065

We (the entity) give ASX the following information under listing rule 3.19A.2 and as agent for the director for the purposes of section 205G of the Corporations Act.

Name of director	Brian Meltzer
Date of last notice	24 April 2025

Part 1 - Change of director’s relevant interests in securities

In the case of a trust, this includes interests in thetrust made available by the responsible entity of the trust

Note: In the case of a company, interests which come within paragraph (i) of the definition of “notifiable interest of a director” should be disclosed in this part.

Direct or indirect interest	(1) Direct<br><br> <br>(2) Indirect - BT PORTFOLIO SERVICES
Nature of indirect interest (including registered holder)	(1) N/A<br><br> <br>(2) SMSF
Date of change	(1.1) N/A<br><br> <br>(1.2) N/A<br><br> <br>(1.3) N/A<br><br> <br>(1.4) N/A<br><br> <br>(1.5) 17 September 2025<br><br> <br>(2) N/A
No. of securities held prior to change	(1.1) 9,415,584 - FULLY PAID ORDINARY SHARES
	(1.2) 2,380,952 - LISTED OPT EXP<br> 31/08/2026 @ $0.01
	(1.3) 757,576 - LISTED OPT EXP 26/02/2027<br> @ $0.028
	(1.4) 30,000,000 - UNLISTED OPT EXP<br> 30/12/2027 @ $0.01
	(1.5) 7,000,000 - UNLISTED OPT EXP<br> 17/09/2025 @ $0.09
	(2) 326,666 - FULLY PAID ORDINARY SHARES

^+^ See chapter 19 for defined terms.

01/01/2011 Appendix 3Y Page 1

Appendix 3Y
Change of Director’s Interest Notice
Class	(1.1) FULLY PAID ORDINARY SHARES<br><br> <br>(1.2) LISTED OPT EXP<br> 31/08/2026 @ $0.01<br><br> <br>(1.3) LISTED OPT EXP 26/02/2027 @ $0.028<br><br> <br>(1.4) UNLISTED<br> OPT EXP 30/12/2027 @ $0.01<br><br> <br>(1.5) UNLISTED OPT EXP 17/09/2025 @ $0.09<br><br> <br>(2) FULLY PAID ORDINARY SHARES
---	---
Number acquired	(1.1) NIL<br><br> <br>(1.2) NIL<br><br> <br>(1.3) NIL<br><br> <br>(1.4) NIL<br><br> <br>(1.5) NIL<br><br> <br>(2) NIL
Number disposed	(1.1) NIL<br><br> <br>(1.2) NIL<br><br> <br>(1.3) NIL<br><br> <br>(1.4) NIL<br><br> <br>(1.5) (7,000,000 - UNLISTED OPT EXP 17/09/2025 @ $0.09)<br><br> <br>(2) NIL
Value/Consideration	(1.1) N/A<br><br> <br>(1.2) N/A<br><br> <br>(1.3) N/A<br><br> <br>(1.4) N/A<br><br> <br>(1.5) NIL CONSIDERATION<br><br> <br>(2) N/A
No. of securities held after change	(1.1) 9,415,584 - FULLY PAID ORDINARY SHARES<br><br> <br>(1.2) 2,380,952 - LISTED OPT EXP 31/08/2026 @ $0.01<br><br> <br>(1.3) 757,576 - LISTED OPT EXP 26/02/2027 @ $0.028<br><br> <br>(1.4) 30,000,000 - UNLISTED OPT EXP 30/12/2027 @<br> $0.01<br><br> <br>(1.5) NIL - UNLISTED OPT EXP 17/09/2025 @ $0.09<br><br> <br>(2) 326,666 - FULLY PAID ORDINARY SHARES

^+^ See chapter 19 for defined terms.

01/01/2011 Appendix 3Y Page 2

Appendix 3Y
Change of Director’s Interest Notice
Nature of change	(1.1) N/A
---	---
	(1.2) N/A
	(1.3) N/A
	(1.4) N/A
	(1.5) Option Expired
	(2) N/A

Part 2 - Change of director’s relevant interests in contracts

Note: In the case of a company, interests which come within paragraph (ii) of the definition of “notifiable interest of a director” should be disclosed in this part.

Detail of contract	N/A
Nature of interest	N/A
Name of registered holder (if issued securities)	N/A
Date of change	N/A
No. and class of securities to which interest related prior to change	N/A
Interest acquired	N/A
Interest disposed	N/A
Value/Consideration	N/A
Interest after change	N/A

Part 3 - ^+^Closed period

Were the interests in the securities or c+ontractsdetailed above traded during a closed period where prior written clearance was required?	No
If so, was prior written clearance provided to allow the trade to proceed during this period?	N/A
If prior written clearance was provided, on what date was this provided?	N/A

^+^ See chapter 19 for defined terms.

01/01/2011 Appendix 3Y Page 3

Appendix 3Y
Change of Director’s Interest Notice

Rule 3.19A.2

Appendix 3Y

Change of Director’s Interest Notice

Informationor documents not available now must be given to ASX as soon as available. Information and documents given to ASX becomes ASX*’sproperty and may be made public.*

Introduced 30/09/01 Amended 01/01/11

Name of entity	Alterity Therapeutics Limited
ABN	37 080 699 065

We (the entity) give ASX the following information under listing rule 3.19A.2 and as agent for the director for the purposes of section 205G of the Corporations Act.

Name of director	Geoffrey Kempler
Date of last notice	30 December 2024

Part 1 - Change of director’s relevant interests in securities

In the case of a trust, this includes interests in thetrust made available by the responsible entity of the trust

Note: In the case of a company, interests which come within paragraph (i) of the definition of “notifiable interest of a director” should be disclosed in this part.

Direct or indirect interest	(1) Direct<br><br> <br>(2) Indirect<br> - NRB Developments Pty Ltd<br><br> <br>(3) Indirect<br> - Sadarajak Pty Ltd<br><br> <br>(4) Direct<br><br> <br>(5) Indirect<br> - Baywick Pty Ltd<br><br> <br>(6) Indirect<br> - Crystal Triangle Pty Ltd
Nature of indirect interest (including registered holder)	(1) N/A<br><br> <br>(2) Director<br> related entity
	(3) Director related entity
	(4) N/A
	(5) Director related entity
	(6) Director related entity
Date of change	(1.1) N/A
	(1.2) 17 September 2025
	(2) N/A
	(3) N/A
	(4) N/A
	(5) N/A
	(6) N/A

^+^ See chapter 19 for defined terms.

01/01/2011 Appendix 3Y Page 1

Appendix 3Y
Change of Director’s Interest Notice
No. of securities held prior to change	(1.1) 60,000,000 - UNLISTED OPT EXP 30/12/2027 @<br> $0.01<br><br> <br>(1.2) 14,000,000 - UNLISTED OPT EXP 17/09/2025 @<br> $0.09<br><br> <br>(2) 2,970,000<br> - FULLY PAID ORDINARY SHARES<br><br> <br>(3) 756,000<br> - FULLY PAID ORDINARY SHARES<br><br> <br>(4) 30,000<br> - FULLY PAID ORDINARY SHARES<br><br> <br>(5) 14,165,000<br> - FULLY PAID ORDINARY SHARES<br><br> <br>(6) 90,000<br> - FULLY PAID ORDINARY SHARES
---	---
Class	(1.1) UNLISTED OPT EXP 30/12/2027 @ $0.01<br><br> <br>(1.2) UNLISTED<br> OPT EXP 17/09/2025 @ $0.09<br><br> <br>(2) FULLY<br> PAID ORDINARY SHARES<br><br> <br>(3) FULLY<br> PAID ORDINARY SHARES<br><br> <br>(4) FULLY<br> PAID ORDINARY SHARES<br><br> <br>(5) FULLY<br> PAID ORDINARY SHARES<br><br> <br>(6) FULLY<br> PAID ORDINARY SHARES
Number acquired	(1.1) NIL<br><br> <br>(1.2) NIL<br><br> <br>(2) NIL<br><br> <br>(3) NIL<br><br> <br>(4) NIL<br><br> <br>(5) NIL<br><br> <br>(6) NIL
Number disposed	(1.1) NIL<br><br> <br>(1.2) (14,000,000 - UNLISTED OPT EXP 17/09/2025 @ $0.09)<br><br> <br>(2) NIL<br><br> <br>(3) NIL<br><br> <br>(4) NIL<br><br> <br>(5) NIL<br><br> <br>(6) NIL
Value/Consideration	(1.1) N/A<br><br> <br>(1.2) NIL CONSIDERATION<br><br> <br>(2) N/A<br><br> <br>(3) N/A<br><br> <br>(4) N/A<br><br> <br>(5) N/A<br><br> <br>(6) N/A

^+^ See chapter 19 for defined terms.

01/01/2011 Appendix 3Y Page 2

Appendix 3Y
Change of Director’s Interest Notice
No. of securities held after change	(1.1) 60,000,000 - UNLISTED OPT EXP 30/12/2027 @<br> $0.01<br><br> <br>(1.2) NIL - UNLISTED OPT EXP 17/09/2025 @ $0.09<br><br> <br>(2) 2,970,000<br> - FULLY PAID ORDINARY SHARES<br><br> <br>(3) 756,000<br> - FULLY PAID ORDINARY SHARES<br><br> <br>(4) 30,000<br> - FULLY PAID ORDINARY SHARES<br><br> <br>(5) 14,165,000<br> - FULLY PAID ORDINARY SHARES<br><br> <br>(6) 90,000<br> - FULLY PAID ORDINARY SHARES
---	---
Nature of change	(1.1) N/A<br><br> <br>(1.2) Option Expired<br><br> <br>(2) N/A<br><br> <br>(3) N/A<br><br> <br>(4) N/A<br><br> <br>(5) N/A<br><br> <br>(6) N/A

Part 2 - Change of director’s relevant interests in contracts

Note: In the case of a company, interests which come within paragraph (ii) of the definition of “notifiable interest of a director” should be disclosed in this part.

Detail of contract	N/A
Nature of interest	N/A
Name of registered holder (if issued securities)	N/A
Date of change	N/A
No. and class of securities to which interest related prior to change	N/A
Interest acquired	N/A
Interest disposed	N/A
Value/Consideration	N/A
Interest after change	N/A

Part 3 - ^+^Closed period

Were the interests in the securities or c+ontractsdetailed above traded during a closed period where prior written clearance was required?	No
If so, was prior written clearance provided to allow the trade to proceed during this period?	N/A
If prior written clearance was provided, on what date was this provided?	N/A

^+^ See chapter 19 for defined terms.

01/01/2011 Appendix 3Y Page 3

Appendix 3Y
Change of Director’s Interest Notice

Rule 3.19A.2

Appendix 3Y

Change of Director’s Interest Notice

Informationor documents not available now must be given to ASX as soon as available. Information and documents given to ASX becomes ASX*’sproperty and may be made public.*

Introduced 30/09/01 Amended 01/01/11

Name of entity	Alterity Therapeutics Limited
ABN	37 080 699 065

We (the entity) give ASX the following information under listing rule 3.19A.2 and as agent for the director for the purposes of section 205G of the Corporations Act.

Name of director	Lawrence Gozlan
Date of last notice	24 April 2025

Part 1 - Change of director’s relevant interests in securities

In the case of a trust, this includes interests in thetrust made available by the responsible entity of the trust

Note: In the case of a company, interests which come within paragraph (i) of the definition of “notifiable interest of a director” should be disclosed in this part.

Direct or indirect interest	(1) Indirect - Montoya Pty Ltd <Buttercup A/C>
Nature of indirect interest (including registered holder)	(1) Director
Date of change	(1.1) N/A
	(1.2) 17 September 2025
	(1.3) N/A
	(1.4) N/A
No. of securities held prior to change	(1.1) 50,000,000 - UNLISTED OPT EXP 30/12/2027 @<br> $0.01
	(1.2)<br> 7,000,000 - UNLISTED OPT EXP 17/09/2025 @ $0.09
	(1.3)<br> 4,545,455 - FULLY PAID ORDINARY SHARES
	(1.4)<br> 1,515,152 - LISTED OPT EXP 26/02/2027 @ $0.028
Class	(1.1) UNLISTED OPT EXP 30/12/2027<br> @ $0.01<br><br> <br>(1.2) UNLISTED OPT EXP 17/09/2025 @ $0.09<br><br> <br>(1.3) FULLY PAID ORDINARY SHARES<br><br> <br>(1.4) LISTED OPT EXP 26/02/2027 @ $0.028

^+^ See chapter 19 for defined terms.

01/01/2011 Appendix 3Y Page 1

Appendix 3Y
Change of Director’s Interest Notice
Number acquired	(1.1) NIL<br><br> <br>(1.2) NIL<br><br> <br>(1.3) NIL<br><br> <br>(1.4) NIL
---	---
Number disposed	(1.1) NIL<br><br> <br>(1.2) (7,000,000 - UNLISTED OPT EXP 17/09/2025 @ $0.09)<br><br> <br>(1.3) NIL<br><br> <br>(1.4) NIL
Value/Consideration	(1.1) N/A<br><br> <br>(1.2) NIL CONSIDERATION<br><br> <br>(1.3) N/A<br><br> <br>(1.4) N/A
No. of securities held after change	(1.1) 50,000,000 - UNLISTED OPT EXP 30/12/2027 @<br> $0.01<br><br> <br>(1.2) NIL - UNLISTED OPT EXP 17/09/2025 @ $0.09<br><br> <br>(1.3) 4,545,455 - FULLY PAID ORDINARY SHARES<br><br> <br>(1.4) 1,515,152 - LISTED OPT EXP 26/02/2027 @ $0.028
Nature of change	(1.1) N/A<br><br> <br>(1.2) Option Expired<br><br> <br>(1.3) N/A<br><br> <br>(1.4) N/A

Part 2 - Change of director’s relevant interests in contracts

Note: In the case of a company, interests which come within paragraph (ii) of the definition of “notifiable interest of a director” should be disclosed in this part.

Detail of contract	N/A
Nature of interest	N/A
Name of registered holder (if issued securities)	N/A
Date of change	N/A
No. and class of securities to which interest related prior to change	N/A
Interest acquired	N/A
Interest disposed	N/A
Value/Consideration	N/A
Interest after change	N/A

Part 3 - ^+^Closed period

Were the interests in the securities or c+ontractsdetailed above traded during a closed period where prior written clearance was required?	No
If so, was prior written clearance provided to allow the trade to proceed during this period?	N/A
If prior written clearance was provided, on what date was this provided?	N/A

^+^ See chapter 19 for defined terms.

01/01/2011 Appendix 3Y Page 2

Appendix 3Y
Change of Director’s Interest Notice

Rule 3.19A.2

Appendix 3Y

Change of Director’s Interest Notice

Informationor documents not available now must be given to ASX as soon as available. Information and documents given to ASX becomes ASX*’sproperty and may be made public.*

Introduced 30/09/01 Amended 01/01/11

Name of entity	Alterity Therapeutics Limited
ABN	37 080 699 065

We (the entity) give ASX the following information under listing rule 3.19A.2 and as agent for the director for the purposes of section 205G of the Corporations Act.

Name of director	Peter Marks
Date of last notice	24 April 2025

Part 1 - Change of director’s relevant interests in securities

In the case of a trust, this includes interests in thetrust made available by the responsible entity of the trust

Note: In the case of a company, interests which come within paragraph (i) of the definition of “notifiable interest of a director” should be disclosed in this part.

Direct or indirect interest	(1) Indirect<br> - Lampam Pty Ltd<br><br> <br>(2) Direct<br><br> <br>(3) Indirect<br> - Shanti Capital Pty Ltd <Peter Marks Super Fund A/C>
Nature of indirect interest (including registered holder)	(1) Director<br><br> <br>(2) N/A<br><br> <br>(3) SMSF
Date of change	(1.1) N/A<br><br> <br>(1.2) N/A<br><br> <br>(2.1) 17 September 2025<br><br> <br>(2.2) N/A<br><br> <br>(3.1) N/A<br><br> <br>(3.2) N/A

^+^ See chapter 19 for defined terms.

01/01/2011 Appendix 3Y Page 1

Appendix 3Y
Change of Director’s Interest Notice
No. of securities held prior to change	(1.1) 7,185,968 - FULLY PAID ORDINARY SHARES<br><br> <br>(1.2) 2,380,952 - LISTED OPT EXP 31/08/2026 @ $0.01<br><br> <br>(2.1) 7,000,000 - UNLISTED OPT EXP 17/09/2025 @ $0.09<br><br> <br>(2.2) 30,000,000 - UNLISTED OPT EXP 30/12/2027 @<br> $0.01<br><br> <br>(3.1) 1,818,182 - FULLY PAID ORDINARY SHARES<br><br> <br>(3.2) 606,061 - LISTED OPT EXP 26/02/2027 @ $0.028
---	---
Class	(1.1) FULLY PAID ORDINARY SHARES<br><br> <br>(1.2) LISTED OPT EXP 31/08/2026 @ $0.01<br><br> <br>(2.1) UNLISTED OPT EXP 17/09/2025<br> @ $0.09<br><br> <br>(2.2) UNLISTED OPT EXP 30/12/2027 @ $0.01<br><br> <br>(3.1) FULLY PAID ORDINARY SHARES<br><br> <br>(3.2) LISTED OPT EXP 26/02/2027 @ $0.028
Number acquired	(1.1) NIL<br><br> <br>(1.2) NIL<br><br> <br>(2.1) NIL<br><br> <br>(2.2) NIL<br><br> <br>(3.1) NIL<br><br> <br>(3.2) NIL
Number disposed	(1.1) NIL<br><br> <br>(1.2) NIL<br><br> <br>(2.1) (7,000,000 - UNLISTED OPT EXP 17/09/2025 @ $0.09)<br><br> <br>(2.2) NIL<br><br> <br>(3.1) NIL<br><br> <br>(3.2) NIL
Value/Consideration	(1.1) N/A<br><br> <br>(1.2) N/A<br><br> <br>(2.1) NIL CONSIDERATION<br><br> <br>(2.2) N/A<br><br> <br>(3.1) N/A<br><br> <br>(3.2) N/A

^+^ See chapter 19 for defined terms.

01/01/2011 Appendix 3Y Page 2

Appendix 3Y
Change of Director’s Interest Notice
No. of securities held after change	(1.1) 7,185,968 - FULLY PAID ORDINARY SHARES<br><br> <br>(1.2) 2,380,952 - LISTED OPT EXP 31/08/2026 @ $0.01<br><br> <br>(2.1) NIL - UNLISTED OPT EXP 17/09/2025 @ $0.09<br><br> <br>(2.2) 30,000,000 - UNLISTED OPT EXP 30/12/2027 @<br> $0.01<br><br> <br>(3.1) 1,818,182 - FULLY PAID ORDINARY SHARES<br><br> <br>(3.2) 606,061 - LISTED OPT EXP 26/02/2027 @ $0.028
---	---
Nature of change	(1.1) N/A<br><br> <br>(1.2) N/A<br><br> <br>(2.1) Options Expired<br><br> <br>(2.2) N/A<br><br> <br>(3.1) N/A<br><br> <br>(3.2) N/A

Part 2 - Change of director’s relevant interests in contracts

Note: In the case of a company, interests which come within paragraph (ii) of the definition of “notifiable interest of a director” should be disclosed in this part.

Detail of contract	N/A
Nature of interest	N/A
Name of registered holder (if issued securities)	N/A
Date of change	N/A
No. and class of securities to which interest related prior to change	N/A
Interest acquired	N/A
Interest disposed	N/A
Value/Consideration	N/A
Interest after change	N/A

Part 3 - ^+^Closedperiod

Were the interests in the securities or c+ontractsdetailed above traded during a closed period where prior written clearance was required?	No
If so, was prior written clearance provided to allow the trade to proceed during this period?	N/A
If prior written clearance was provided, on what date was this provided?	N/A

^+^ See chapter 19 for defined terms.

01/01/2011 Appendix 3Y Page 3