Commitments and Contingencies	9 Months Ended
Sep. 30, 2026
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Commitments The Company has entered into agreements as of September 30, 2026 primarily regarding the clinical and non-clinical development services with contract research organizations, as well as supply and logistics services with contract manufacturing organizations, for the advancement of SLK. As of September 30, 2026, the total committed expense under these agreements amounted to $152.1 million. The Company's in-licensing agreement (the “In-License Agreement”) with Merck Healthcare KGaA, Darmstadt, Germany ("MHKDG") includes contractual milestone payments related to the achievement of pre-specified research, development, regulatory and commercialization events and indemnification provisions, which are common in such agreements. Pursuant to the agreements, the Company is obligated to make research and development and regulatory milestone payments upon the occurrence of certain events. Subject to the terms of the license, additional milestone payments of up to €299.6 million ($339.4 million using a September 30, 2026 exchange rate) are potentially payable upon satisfying specific milestones related to regulatory filing acceptance, first commercial sales, and aggregate annual net sales. The milestone payments are payable in cash. Milestone payments due prior to obtaining regulatory approval will be recorded as research and development expense upon determination that a milestone payment is probable to occur. Milestone payments due after obtaining regulatory approval will be capitalized when and if incurred. The Company will use commercially reasonable efforts to cause the milestones to occur. However, if the Company reasonably determines that a technical failure or commercial failure has occurred with respect to all or a part of the SLK Program, the Company, at its sole discretion, can terminate all or part of the SLK Program. As of September 30, 2026, the Company made a total of €7.5 million ($8.1 million using the then applicable exchange rate) in additional milestone payments and accrued €15.0 million ($17.0 million using the period end exchange rate) for a regulatory milestone associated with FDA acceptance of the Company's BLA submission for SLK. The amount was included in accrued expenses and other current liabilities and research and development expense and had not been invoiced or paid as of September 30, 2026. In addition, on May 12, 2023, MoonLake AG entered into an agreement with Research Corporation Technologies, Inc. (“RCT”) and MHKDG, effective as of June 1, 2023, pursuant to which the Company was granted a royalty-bearing, nonexclusive, sublicensable right and license under RCT’s patents and know-how related to a manufacturing process using an underlying yeast strain, Pichia pastoris, to develop, manufacture, use, sell, offer for sale, and import and otherwise commercialize SLK on a world-wide basis, subject to certain restrictions. This agreement replaces the Company’s sublicense for similar rights under the In-License Agreement. In the aggregate, the Company is required to pay royalties within the range of low to mid-teen percent of net sales under the aforementioned agreements with MHKDG and RCT. Royalties will be recognized in the condensed consolidated statements of operations and comprehensive loss when net sales are recognized. Office Lease Not Yet Commenced On July 1, 2026, the Company entered into to a new lease agreement for a corporate office space in Miami, Florida that is expected to commence before the end of 2026, for additional office space in Miami, Florida with a lease term of approximately 11 years. Total minimum lease payments are estimated to be approximately $16.5 million. The Company will recognize the related right-of-use asset and lease liability, which has not yet been determined, at the lease commencement date.

The Company has entered into agreements as of September 30, 2026 primarily regarding the clinical and non-clinical development services with contract research organizations, as well as supply and logistics services with contract manufacturing organizations, for the advancement of SLK. As of September 30, 2026, the total committed expense under these agreements amounted to $152.1 million.

The Company's in-licensing agreement (the “In-License Agreement”) with Merck Healthcare KGaA, Darmstadt, Germany ("MHKDG") includes contractual milestone payments related to the achievement of pre-specified research, development, regulatory and commercialization events and indemnification provisions, which are common in such agreements. Pursuant to the agreements, the Company is obligated to make research and development and regulatory milestone payments upon the occurrence of certain events. Subject to the terms of the license, additional milestone payments of up to €299.6 million ($339.4 million using a September 30, 2026 exchange rate) are potentially payable upon satisfying specific milestones related to regulatory filing acceptance, first commercial sales, and aggregate annual net sales. The milestone payments are payable in cash. Milestone payments due prior to obtaining regulatory approval will be recorded as research and development expense upon determination that a milestone payment is probable to occur. Milestone payments due after obtaining regulatory approval will be capitalized when and if incurred. The Company will use commercially reasonable efforts to cause the milestones to occur. However, if the Company reasonably determines that a technical failure or commercial failure has occurred with respect to all or a part of the SLK

Program, the Company, at its sole discretion, can terminate all or part of the SLK Program. As of September 30, 2026, the Company made a total of €7.5 million ($8.1 million using the then applicable exchange rate) in additional milestone payments and accrued €15.0 million ($17.0 million using the period end exchange rate) for a regulatory milestone associated with FDA acceptance of the Company's BLA submission for SLK. The amount was included in accrued expenses and other current liabilities and research and development expense and had not been invoiced or paid as of September 30, 2026.

In addition, on May 12, 2023, MoonLake AG entered into an agreement with Research Corporation Technologies, Inc. (“RCT”) and MHKDG, effective as of June 1, 2023, pursuant to which the Company was granted a royalty-bearing, nonexclusive, sublicensable right and license under RCT’s patents and know-how related to a manufacturing process using an underlying yeast strain, Pichia pastoris, to develop, manufacture, use, sell, offer for sale, and import and otherwise commercialize SLK on a world-wide basis, subject to certain restrictions. This agreement replaces the Company’s sublicense for similar rights under the In-License Agreement. In the aggregate, the Company is required to pay royalties within the range of low to mid-teen percent of net sales under the aforementioned agreements with MHKDG and RCT.

On July 1, 2026, the Company entered into to a new lease agreement for a corporate office space in Miami, Florida that is expected to commence before the end of 2026, for additional office space in Miami, Florida with a lease term of approximately 11 years. Total minimum lease payments are estimated to be approximately $16.5 million. The Company will recognize the related right-of-use asset and lease liability, which has not yet been determined, at the lease commencement date.