Asset Acquisition	12 Months Ended
Dec. 31, 2023
Asset Acquisition
Asset Acquisition	3. Asset Acquisition Xinvento B.V. On February 27, 2023, the Company, through its wholly-owned Dutch subsidiary, Rhythm Pharmaceuticals Netherlands B.V., a Dutch private limited liability company (“Rhythm BV”), entered into a Share Purchase Agreement (the “Purchase Agreement”) with Xinvento B.V., a Dutch private limited liability company based in the Netherlands (“Xinvento”), and the other parties named therein, pursuant to which, and concurrently with the execution thereof, Rhythm BV acquired all of the issued and outstanding shares of Xinvento. The aggregate consideration at closing was approximately $5,667, inclusive of transaction costs, as adjusted pursuant to the terms of the Purchase Agreement and subject to the distribution and payment terms set forth therein (the “Closing Purchase Price”). In addition to the Closing Purchase Price, the Purchase Agreement provides for the payment of additional contingent consideration totaling up to $206,000 upon achievement of certain development, regulatory and commercial milestones by Xinvento, as follows: (i) up to an aggregate of $6,000 in clinical development milestones; (ii) up to an aggregate of $125,000 in regulatory approval and commercial milestones; and (iii) up to an aggregate of $75,000 in sales milestones in the event a second molecule is selected, developed and approved. The total purchase consideration of $5,667 was composed of $4,520 of cash paid at closing, a $500 holdback, payable on the one-year anniversary of the acquisition, and $647 of acquisition-related costs. The $500 holdback will be paid in the quarter ended March 31, 2024. The Company determined that substantially all of the value as of acquisition date related to Xinvento’s In-Process Research and Development. As a result, the Company determined this transaction should be accounted for as an asset acquisition. The assets acquired were In-Process Research and Development (IPR&D) assets. However, since the IPR&D assets were determined to have no alternative future use, the Company recognized the $5,667 of purchase consideration as research and development expense in the year ended December 31, 2023. The Company determined that the additional contingent consideration did not meet the definition of a derivative as of the acquisition date. Therefore, the Company did not record a contingent consideration liability on the acquisition date. The Company will recognize any future contingent consideration payments related to the Xinvento transaction in the period in which the achievement of the underlying milestones becomes probable. Xinvento's results of operations are included in the consolidated financial statements from the date of acquisition. For the year ended December 31, 2023, the net loss associated with the operations of Xinvento was de minimis in the Company’s consolidated statements of operations.

Asset Acquisition

12 Months Ended

Dec. 31, 2023

3. Asset Acquisition

Xinvento B.V.

On February 27, 2023, the Company, through its wholly-owned Dutch subsidiary, Rhythm Pharmaceuticals Netherlands B.V., a Dutch private limited liability company (“Rhythm BV”), entered into a Share Purchase Agreement (the “Purchase Agreement”) with Xinvento B.V., a Dutch private limited liability company based in the Netherlands (“Xinvento”), and the other parties named therein, pursuant to which, and concurrently with the execution thereof, Rhythm BV acquired all of the issued and outstanding shares of Xinvento. The aggregate consideration at closing was approximately $5,667, inclusive of transaction costs, as adjusted pursuant to the terms of the Purchase Agreement and subject to the distribution and payment terms set forth therein (the “Closing Purchase Price”).

In addition to the Closing Purchase Price, the Purchase Agreement provides for the payment of additional contingent consideration totaling up to $206,000 upon achievement of certain development, regulatory and commercial milestones by Xinvento, as follows: (i) up to an aggregate of $6,000 in clinical development milestones; (ii) up to an aggregate of $125,000 in regulatory approval and commercial milestones; and (iii) up to an aggregate of $75,000 in sales milestones in the event a second molecule is selected, developed and approved.

The total purchase consideration of $5,667 was composed of $4,520 of cash paid at closing, a $500 holdback, payable on the one-year anniversary of the acquisition, and $647 of acquisition-related costs. The $500 holdback will be paid in the quarter ended March 31, 2024. The Company determined that substantially all of the value as of acquisition date related to Xinvento’s In-Process Research and Development. As a result, the Company determined this transaction should be accounted for as an asset acquisition.

The assets acquired were In-Process Research and Development (IPR&D) assets. However, since the IPR&D assets were determined to have no alternative future use, the Company recognized the $5,667 of purchase consideration as research and development expense in the year ended December 31, 2023.

The Company determined that the additional contingent consideration did not meet the definition of a derivative as of the acquisition date. Therefore, the Company did not record a contingent consideration liability on the acquisition date. The Company will recognize any future contingent consideration payments related to the Xinvento transaction in the period in which the achievement of the underlying milestones becomes probable.

Xinvento's results of operations are included in the consolidated financial statements from the date of acquisition. For the year ended December 31, 2023, the net loss associated with the operations of Xinvento was de minimis in the Company’s consolidated statements of operations.