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Check the appropriate box to designate the rule pursuant to which this Schedule is filed:
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SCHEDULE 13D/A 0000918923 XXXXXXXX LIVE 4 Class A ordinary share, par value $0.0001 per share 11/06/2025 false 0001821586 61559X104 MoonLake Immunotherapeutics DORFSTRASSE 29 ZUG V8 6300 JAMES KRATKY 415-525-8830 BVF PARTNERS L.P. 44 Montgomery St., 40th Floor San Francisco CA 94104 0000918923 N BIOTECHNOLOGY VALUE FUND L P a WC N DE 0.00 10235089.00 0.00 10235089.00 10235089.00 N 14.3 PN 0001803805 N BVF I GP LLC a AF N DE 0.00 10235089.00 0.00 10235089.00 10235089.00 N 14.3 OO 0001102444 N BIOTECHNOLOGY VALUE FUND II LP a WC N DE 0.00 8168838.00 0.00 8168838.00 8168838.00 N 11.4 PN 0001803806 N BVF II GP LLC a AF N DE 0.00 8168838.00 0.00 8168838.00 8168838.00 N 11.4 OO 0001660683 N Biotechnology Value Trading Fund OS LP a WC N E9 0.00 1287768.00 0.00 1287768.00 1287768.00 N 1.8 PN 0001660684 N BVF Partners OS Ltd. a AF N E9 0.00 1287768.00 0.00 1287768.00 1287768.00 N 1.8 CO 0001803809 N BVF GP HOLDINGS LLC a AF N DE 0.00 18403927.00 0.00 18403927.00 18403927.00 N 25.8 OO 0001055947 N BVF PARTNERS L P/IL a AF N DE 0.00 19751284.00 0.00 19751284.00 19751284.00 N 27.7 IA PN 0001056807 N BVF INC/IL a AF N DE 0.00 19751284.00 0.00 19751284.00 19751284.00 N 27.7 CO 0001233840 N LAMPERT MARK N a AF N X1 0.00 19751284.00 0.00 19751284.00 19751284.00 N 27.7 IN 0001920549 N Loy Spike a OO N X1 18985.00 0.00 18985.00 0.00 18985.00 N 0.03 IN Class A ordinary share, par value $0.0001 per share MoonLake Immunotherapeutics DORFSTRASSE 29 ZUG V8 6300 This Amendment No. 4 to the Schedule 13D is being filed due to a change in the percentage of the outstanding number of Shares owned by the Reporting Persons solely due to an increase in the number of Shares outstanding. 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 on 71,373,579 Shares outstanding as of November 6, 2025, which is the total number of Shares outstanding following the closing of the Issuer's offering as reported in the Issuer's Prospectus Supplement filed with the Securities and Exchange Commission on November 5, 2025. Item 5(b) is hereby amended and restated to read as follows: As of the date hereof, (i) BVF beneficially owned 10,235,089 Shares, representing percentage ownership of approximately 14.3% of the Shares outstanding, (ii) BVF2 beneficially owned 8,168,838 Shares, representing percentage ownership of approximately 11.4% of the Shares outstanding, (iii) Trading Fund OS beneficially owned 1,287,768 Shares, representing percentage ownership of approximately 1.8% of the Shares outstanding, and (iv) 59,589 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 10,235,089 Shares beneficially owned by BVF, representing percentage ownership of approximately 14.3% of the Shares outstanding. BVF2 GP, as the general partner of BVF2, may be deemed to beneficially own the 8,168,838 Shares beneficially owned by BVF2, representing percentage ownership of approximately 11.4% of the Shares outstanding. Partners OS, as the general partner of Trading Fund OS, may be deemed to beneficially own the 1,287,768 Shares beneficially owned by Trading Fund OS, representing percentage ownership of approximately 1.8% 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 18,403,927 Shares beneficially owned in the aggregate by BVF and BVF2, representing percentage ownership of approximately 25.8% 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 19,751,284 Shares beneficially owned in the aggregate by BVF, BVF2 and Trading Fund OS and held in the Partners Managed Account, representing percentage ownership of approximately 27.7% of the Shares outstanding. BVF Inc., as the general partner of Partners, may be deemed to beneficially own the 19,751,284 Shares beneficially owned by Partners, representing percentage ownership of approximately 27.7% of the Shares outstanding. Mr. Lampert, as a director and officer of BVF Inc., may be deemed to beneficially own the 19,751,284 Shares beneficially owned by BVF Inc., representing percentage ownership of approximately 27.7% of the Shares outstanding. As of the date hereof, Mr. Loy beneficially owned 18,985 Shares, which consist of Shares issuable upon the exercise of certain options that are exercisable within sixty days hereof, representing percentage ownership of less than 1%. Item 5(c) is hereby amended and restated to read as follows: The Reporting Persons have not entered into any transactions in the securities of the Issuer during the past sixty days. Item 6 is hereby amended to add the following: On June 5, 2025, Mr. Loy was granted stock options in connection with his service as a director of the Issuer that represent a right to purchase 6,682 Shares. Such options (a) will vest in full on the earlier of (i) June 5, 2026 and (ii) the date of the Issuer's next annual general meeting of shareholders, subject to Mr. Loy's continued service to the Issuer, (b) have an exercise price of $48.83 per Share and (c) expire on June 5, 2035. BIOTECHNOLOGY VALUE FUND L P /s/ Mark N. Lampert Mark N. Lampert, Authorized Signatory 11/10/2025 BVF I GP LLC /s/ Mark N. Lampert Mark N. Lampert, Authorized Signatory 11/10/2025 BIOTECHNOLOGY VALUE FUND II LP /s/ Mark N. Lampert Mark N. Lampert, Authorized Signatory 11/10/2025 BVF II GP LLC /s/ Mark N. Lampert Mark N. Lampert, Authorized Signatory 11/10/2025 Biotechnology Value Trading Fund OS LP /s/ Mark N. Lampert Mark N. Lampert, Authorized Signatory 11/10/2025 BVF Partners OS Ltd. /s/ Mark N. Lampert Mark N. Lampert, Authorized Signatory 11/10/2025 BVF GP HOLDINGS LLC /s/ Mark N. Lampert Mark N. Lampert, Authorized Signatory 11/10/2025 BVF PARTNERS L P/IL /s/ Mark N. Lampert Mark N. Lampert, Authorized Signatory 11/10/2025 BVF INC/IL /s/ Mark N. Lampert Mark N. Lampert, Authorized Signatory 11/10/2025 LAMPERT MARK N /s/ Mark N. Lampert Mark N. Lampert 11/10/2025 Loy Spike /s/ Spike Loy Spike Loy 11/10/2025