Jorge Santos da Silva - 19 Dec 2025 Form 4 Insider Report for MoonLake Immunotherapeutics (MLTX)

Reporting relationship: Chief Executive Officer, Director
Issuer ticker: MLTX
Reported as of: 19 Dec 2025
Net transaction value: $0
SEC form: 4
Accepted by SEC: 22 Dec 2025, 16:01:24 UTC
Prior SEC filing: 10 Dec 2025
Next SEC filing: 09 Jan 2026
Source filing: View source filing
Reporting owner signature: /s/ Matthias Bodenstedt, Attorney-in-fact for Jorge Santos da Silva

Key filing fact

Jorge Santos da Silva filed Form 4 for MoonLake Immunotherapeutics (MLTX) on 22 Dec 2025.

Key facts

This page summarizes Jorge Santos da Silva's Form 4 filing for MoonLake Immunotherapeutics (MLTX).
3 reported transactions and 1 derivative row are listed below.
Accepted by SEC: 22 Dec 2025, 16:01.

Change

Previous filing in this sequence was filed on 10 Dec 2025.
Current net transaction value: $0.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001920509 Primary reporting owner

Santos da Silva Jorge

Relationship: Chief Executive Officer, Director
Address: C/O MOONLAKE IMMUNOTHERAPEUTICS, DORFSTRASSE 29, ZUG, SWITZERLAND
Signature: /s/ Matthias Bodenstedt, Attorney-in-fact for Jorge Santos da Silva
Signature date: 22 Dec 2025

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

MLTX transaction

Class A ordinary shares, par value $0.0001 per share

Conversion of derivative security

Transaction value
Shares: +196,316
Change %: +6.8%
Price
Shares after: 3,074,893
Date: 19 Dec 2025
Ownership: Direct
Footnotes: F1, F2

MLTX transaction

Class C ordinary shares, par value $0.0001 per share

Disposed to Issuer

Transaction value
Shares: -196,316
Change %: -100%
Price
Shares after: 0
Date: 19 Dec 2025
Ownership: Direct
Footnotes: F1, F2, F3, F4

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

MLTX transaction Derivative

Common shares, par value CHF 0.10 per share, of MoonLake AG

Conversion of derivative security

Transaction value
Shares: -5,836
Change %: -100%
Price
Shares after: 0
Date: 19 Dec 2025
Ownership: Direct
Underlying class: Class A ordinary shares, par value $0.0001 per share
Underlying amount: 196,316
Exercise price
Footnotes: F1, F2, F3, F4

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 4 footnotes

Footnote F1

On December 19, 2025, the Reporting Person exchanged 5,836 common shares of MoonLake Immunotherapeutics AG ("MoonLake AG") for 196,316 Class A ordinary shares of the Issuer. In connection with the exchange, 196,316 Class C ordinary shares of the Issuer were automatically cancelled by the Issuer for no consideration.

Footnote F2

The common shares of MoonLake AG may be exchanged at the holder's option into Class A ordinary shares at a rate of 1 common share of MoonLake AG for 33.638698 Class A ordinary shares, rounded to the nearest whole share. Upon any such exchange of a common share of MoonLake AG, the corresponding Class C ordinary share of the Issuer will be automatically cancelled.

Footnote F3

10,000 of the common shares of MoonLake AG held by the holder (the "second leaver shares") are subject to a reverse vesting condition, such that 25% vested on January 18, 2023 and 75% vest on the 18th of each month at a rate of 2.08%, and they will be fully vested on January 18, 2026 (the "second vesting period"). Upon the occurrence of any transfer of MoonLake AG shares in one or a series of related transactions that results in the proposed acquiror holding directly, or indirectly through one or more intermediaries, more than 50% of the then issued share capital of MoonLake AG, the unvested second leaver shares will fully vest.

Footnote F4

(continued from footnote 3) If, before the end of the second vesting period the employment relationship of the holder is terminated (a) for any reason other than for cause, MoonLake AG or any third party designated by it, shall have an option to purchase all or a pro rata portion of the unvested second leaver shares at nominal value of CHF 0.10 per share or (b) for cause, MoonLake AG or any third party designated by it, shall have an option to purchase all or a pro rata portion of the second leaver shares at nominal value of CHF 0.10 per share. In connection with any such purchase of such second leaver shares, the corresponding Class C ordinary shares of the Issuer will also be transferred to the purchaser.