MPM BioImpact LLC Establishes 7.2% Passive Stake in Forte Biosciences, Inc. (FBRX)

On May 15, 2026, MPM BioImpact LLC filed a Schedule 13G with the SEC, reporting a new ownership stake in Forte Biosciences, Inc. (FBRX). As of the event date of March 31, 2026, the Boston-based investment adviser reported beneficial ownership of 1,000,682 shares of Common Stock, representing 7.2% of the company's outstanding shares. This filing marks a significant increase from a previous 0.0% position, establishing MPM BioImpact LLC as a major shareholder. The filing indicates that MPM BioImpact LLC holds sole voting and dispositive power over the entire reported amount. The acquisition was made in the ordinary course of business and is classified as a passive investment, as certified under Rule 13d-1(b), meaning the shares were not acquired for the purpose of influencing or changing the control of the issuer. Forte Biosciences is headquartered in Dallas, Texas, and focuses on biopharmaceutical developments.