Form SC 13G/A - Statement of Beneficial Ownership by Certain Investors: [Amend]

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549



SCHEDULE 13G/A



Under the Securities Exchange Act of 1934

(Amendment No. 1)*

Acadia Pharmaceuticals Inc.
(Name of Issuer)

Common Stock, par value $0.0001 per share
(Title of Class of Securities)

004225108
(CUSIP Number)

September 30, 2024
(Date of event which requires filing of this statement)


Check the appropriate box to designate the rule pursuant to which this Schedule 13G/A is filed:

x	Rule 13d-1(b)
¨	Rule 13d-1(c)
¨	Rule 13d-1(d)

(Page 1 of 7 Pages)

______________________________

* 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 the disclosures provided in a prior cover page.

The information required in 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 (the "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. 004225108

13G/A

Page 2 of 7 Pages

1	NAMES OF REPORTING PERSONS RTW Investments, LP
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP		(a) ¨ (b) ¨
3	SEC USE ONLY
4	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	5	SOLE VOTING POWER - 0 -
	6	SHARED VOTING POWER 13,707,506 Shares
	7	SOLE DISPOSITIVE POWER - 0 -
	8	SHARED DISPOSITIVE POWER 13,707,506 Shares
9	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 13,707,506 Shares
10	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES			¨
11	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 8.3%
12	TYPE OF REPORTING PERSON PN, IA

CUSIP No. 004225108

13G/A

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1	NAMES OF REPORTING PERSONS Roderick Wong, M.D.
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP		(a) ¨ (b) ¨
3	SEC USE ONLY
4	CITIZENSHIP OR PLACE OF ORGANIZATION United States
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH	5	SOLE VOTING POWER - 0 -
	6	SHARED VOTING POWER 13,707,506 Shares
	7	SOLE DISPOSITIVE POWER - 0 -
	8	SHARED DISPOSITIVE POWER 13,707,506 Shares
9	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 13,707,506 Shares
10	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES			¨
11	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 8.3%
12	TYPE OF REPORTING PERSON IN, HC

CUSIP No. 004225108

13G/A

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Item 1(a).	NAME OF ISSUER:

	The name of the issuer is Acadia Pharmaceuticals Inc. (the "Company").

Item 1(b).	ADDRESS OF ISSUER'S PRINCIPAL EXECUTIVE OFFICES:

	The Company's principal executive offices are located at 12830 El Camino Real, Suite 400, San Diego, California 92130.

Item 2(a).	NAME OF PERSON FILING:

	This statement is filed by:

(i)

RTW Investments, LP ("RTW Investments"), a Delaware limited partnership, and the investment adviser to certain funds (the "RTW Funds"), with respect to the Shares (as defined in Item 2(d) below) directly held by the RTW Funds; and

(ii)

Roderick Wong, M.D. ("Dr. Wong"), the Managing Partner and Chief Investment Officer of RTW Investments, with respect to the Shares directly held by the RTW Funds.

	The foregoing persons are hereinafter sometimes collectively referred to as the "Reporting Persons."

	The filing of this statement should not be construed as an admission that any of the foregoing persons or any Reporting Person is, for the purposes of Section 13 of the Act, the beneficial owner of the Shares reported herein.

Item 2(b).	ADDRESS OF PRINCIPAL BUSINESS OFFICE OR, IF NONE, RESIDENCE:

	The address of the business office of each of the Reporting Persons is 40 10^th Avenue, Floor 7, New York, New York 10014.

Item 2(c).	CITIZENSHIP:

	RTW Investments is a Delaware limited partnership. Dr. Wong is a citizen of the United States.

Item 2(d).	TITLE OF CLASS OF SECURITIES:

	Common Stock, par value $0.0001 per share (the "Shares").

Item 2(e).	CUSIP NUMBER:

	004225108

CUSIP No. 004225108

13G/A

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Item 3.

IF THIS STATEMENT IS FILED PURSUANT TO §§ 240.13d-1(b) OR 240.13d-2(b) OR (c), CHECK WHETHER THE PERSON FILING IS A:

(a)	¨	Broker or dealer registered under Section 15 of the Act (15 U.S.C. 78o);
(b)	¨	Bank as defined in Section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)	¨	Insurance company as defined in Section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)	¨	Investment company registered under Section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)	x	Investment adviser in accordance with Rule 13d-1(b)(1)(ii)(E);
(f)	¨	Employee benefit plan or endowment fund in accordance with Rule 13d-1(b)(1)(ii)(F);
(g)	x	Parent holding company or control person in accordance with Rule 13d-1(b)(1)(ii)(G);
(h)	¨	Savings association as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)	¨	Church plan that is excluded from the definition of an investment company under Section 3(c)(14) of the Investment Company Act (15 U.S.C. 80a-3);
(j)	¨	Non-U.S. institution in accordance with Rule 13d-1(b)(1)(ii)(J);
(k)	¨	Group, in accordance with Rule 13d-1(b)(1)(ii)(K).

If filing as a non-U.S. institution in accordance with Rule 13d-1(b)(1)(ii)(J), please specify the type of institution: ______________________________________________________

Item 4.	OWNERSHIP:

	The information required by Items 4(a) - (c) is set forth in Rows 5 - 11 of the cover page for each of the Reporting Persons and is incorporated herein by reference.

	The percentages set forth herein are calculated based upon 165,876,052 Shares outstanding as of July 31, 2024 as reported in the Company’s Quarterly Report on Form 10-Q for the quarterly period ended June 30, 2024, filed with the Securities and Exchange Commission on August 7, 2024.

Item 5.	OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS:

	Not applicable.

CUSIP No. 004225108

13G/A

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Item 6.	OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF ANOTHER PERSON:

	See Item 2. The RTW Funds have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the Shares reported herein.

Item 7.	IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH ACQUIRED THE SECURITY BEING REPORTED ON BY THE PARENT HOLDING COMPANY:

	Not applicable.

Item 8.	IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP:

	Not applicable.

Item 9.	NOTICE OF DISSOLUTION OF GROUP:

	Not applicable.

Item 10.	CERTIFICATION:

	Each of the Reporting Persons hereby makes the following certification:

	By signing below each Reporting Person certifies that, to the best of his or its knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect.

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13G/A

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SIGNATURES

After reasonable inquiry and to the best of his or its knowledge and belief, each of the undersigned certify that the information set forth in this statement is true, complete and correct.

DATED: November 14, 2024