Foresite Capital and James B. Tananbaum Report Share Distributions in Alumis Inc. (ALMS) Amendment No. 4

This Amendment No. 4 to Schedule 13D, filed on April 3, 2026, reflects a change in the beneficial ownership of Alumis Inc. (ALMS) by James B. Tananbaum and a group of entities associated with Foresite Capital. The primary purpose of this filing is to report the disposition of Common Stock by Foresite Labs Affiliates 2021, LLC and Foresite Labs, LLC. On April 1, 2026, Labs Affiliates and Labs effected pro rata distributions of 1,176,470 and 1,123,337 shares, respectively, to their members for no consideration. Following these distributions, Foresite Labs Affiliates 2021, LLC and Foresite Labs, LLC no longer hold any shares. However, James B. Tananbaum remains a significant beneficial owner, holding an aggregate of 15,693,820 shares, representing 12.7% of the company's outstanding common stock. These holdings are distributed across several entities including Foresite Capital Fund VI, Fund V, Opportunity Fund V, and Labs Fund I. The reporting persons maintain their positions for investment purposes and may adjust their holdings based on market conditions.