SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G/A
Under the Securities Exchange Act of 1934
(Amendment No. 4)*
Marinus Pharmaceuticals, Inc.
(Name of Issuer)
Common Stock, par value $0.001 per share
(Title of Class of Securities)
56854Q200
(CUSIP Number)
December 31, 2023
(Date of Event Which Requires Filing of This Statement)
Check the appropriate box to designate the rule pursuant to which this Schedule is filed:
þ	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 (“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. 56854Q200 13G/A Page 2 of 7 Pages

1	NAME OF REPORTING PERSON Avoro Capital Advisors LLC
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP		(a) ¨ (b) þ
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 3,150,000
	6	SHARED VOTING POWER 0
	7	SOLE DISPOSITIVE POWER 3,150,000
	8	SHARED DISPOSITIVE POWER 0
9	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 3,150,000
10	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES			¨
11	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 5.8%
12	TYPE OF REPORTING PERSON OO, IA

CUSIP No. 56854Q200 13G/A Page 3 of 7 Pages

1	NAME OF REPORTING PERSON Behzad Aghazadeh
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP		(a) ¨ (b) þ
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 3,150,000
	6	SHARED VOTING POWER 0
	7	SOLE DISPOSITIVE POWER 3,150,000
	8	SHARED DISPOSITIVE POWER 0
9	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 3,150,000
10	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES			¨
11	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 5.8%
12	TYPE OF REPORTING PERSON IN

CUSIP No. 56854Q200 13G/A Page 4 of 7 Pages

Item 1(a).	NAME OF ISSUER
	Marinus Pharmaceuticals, Inc. (the “Issuer”)

Item 1(b).	ADDRESS OF ISSUER’S PRINCIPAL EXECUTIVE OFFICES
	5 Radnor Corporate Center, Suite 500, 100 Matsonford Rd, Radnor, PA 19087

Item 2(a).	NAME OF PERSON FILING
	This statement is filed by: (i) Avoro Capital Advisors LLC, a Delaware limited liability company (“Avoro”), which provides investment advisory and management services and has acquired the securities of the Issuer solely for investment purposes on behalf of Avoro Life Sciences Fund LLC, a Delaware limited liability company, and (ii) Behzad Aghazadeh (“Dr. Aghazadeh,” and together with Avoro, the “Reporting Persons”), who serves as the portfolio manager and controlling person of Avoro.
	The filing of this statement should not be construed as an admission that any Reporting Person is, for purposes of Section 13 of the Act, the beneficial owner of the securities 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 110 Greene Street, Suite 800, New York, NY 10012.

Item 2(c).	CITIZENSHIP
	Avoro is a Delaware limited liability company.  Dr. Aghazadeh is a United States citizen.

Item 2(d).	TITLE OF CLASS OF SECURITIES
	Common Stock, par value $0.001 per share (the “Common Stock”)

Item 2(e).	CUSIP NUMBER
	56854Q200

Item 3. IF THIS STATEMENT IS FILED PURSUANT TO Rules 13d-1(b), OR 13d-2(b) OR (c), CHECK WHETHER THE PERSON FILING IS A:

(a)	¨	Broker or dealer registered under Section 15 of the Act;
(b)	¨	Bank as defined in Section 3(a)(6) of the Act;
(c)	¨	Insurance company as defined in Section 3(a)(19) of the Act;
(d)	¨	Investment company registered under Section 8 of the Investment Company Act of 1940;
(e)	þ	An investment adviser in accordance with Rule 13d-1(b)(1)(ii)(E);

CUSIP No. 56854Q200 13G/A Page 5 of 7 Pages

(f)	¨	An employee benefit plan or endowment fund in accordance with Rule 13d-1(b)(1)(ii)(F);
(g)	þ	A parent holding company or control person in accordance with Rule 13d-1(b)(1)(ii)(G);
(h)	¨	A savings association as defined in Section 3(b) of the Federal Deposit Insurance Act;
(i)	¨	A church plan that is excluded from the definition of an investment company under Section 3(c)(14) of the Investment Company Act;
(j)	¨	A 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 and is incorporated herein by reference.
	The percentage set forth in Row 11 of this Schedule 13G/A is calculated based upon 54,573,581 shares of Common Stock outstanding as of November 3, 2023 as reported in the Issuer’s Quarterly Report on Form 10-Q for the quarterly period ended September 30, 2023, filed with the Securities and Exchange Commission on November 7, 2023.

Item 5.	OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS
	Not applicable.

Item 6.	OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF ANOTHER PERSON
	See Item 2.  Avoro Life Sciences Fund LLC has the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, more than 5% of the Common Stock.

Item 7.	IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH ACQUIRED THE SECURITY BEING REPORTED ON BY THE PARENT HOLDING COMPANY OR CONTROL PERSON
	Not applicable.

Item 8.	IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP
	Not applicable.

Item 9.	NOTICE OF DISSOLUTION OF GROUP
	Not applicable.

CUSIP No. 56854Q200 13G/A Page 6 of 7 Pages

Item 10. CERTIFICATION

Each Reporting Person hereby makes the following certification:

By signing below the 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 and are not held 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.

CUSIP No. 56854Q200 13G/A Page 7 of 7 Pages

SIGNATURES

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

DATE: February 14, 2024

AVORO CAPITAL ADVISORS LLC

/s/ Scott Epstein

Name:   Scott Epstein

Title:     Chief Financial Officer
              & Chief Compliance Officer

/s/ Behzad Aghazadeh

BEHZAD AGHAZADEH