Baker Bros. Advisors LP and affiliated reporting persons filed Amendment No. 5 to Schedule 13D with the SEC on November 6, 2026, disclosing a beneficial ownership position of 9.99% in Madrigal Pharmaceuticals, Inc. following additional acquisitions of common stock.

Key Highlights

  • Beneficial ownership: Each of the four reporting persons - Baker Bros. Advisors LP, Baker Bros. Advisors (GP) LLC, Julian C. Baker, and Felix J. Baker - reported aggregate beneficial ownership of 2,330,144 shares, representing 9.99% of the class.
  • Sole voting and dispositive power: All 2,330,144 shares are held with sole voting power and sole dispositive power; shared voting and dispositive power are each reported as 0.00.
  • Triggering event: The amendment was filed to report an acquisition of common stock that resulted in a more than 1 percent change in beneficial ownership, according to the filing.
  • Share count basis: The 9.99% figure is based on 23,229,561 shares of common stock outstanding as of October 29, 2026, plus 90,417 shares issuable upon exercise of Prefunded Warrants and 4,790 vested non-qualified options exercisable for 4,790 shares of common stock.
  • Source of funds: The source of funds is listed as "OO" (other) for all reporting persons, with a note that securities may be held in margin accounts and pledged as collateral for prime broker debit balances.
  • Investment purpose: According to the filing, the Funds hold the issuer's securities "for investment purposes," and the reporting persons may purchase additional securities or dispose of securities depending on assessments of various factors.

Baker Bros. Advisors Discloses Increased Position in Madrigal Pharmaceuticals

According to the filing, this Amendment No. 5 to Schedule 13D amends and supplements a previously filed Schedule 13D submitted by Baker Bros. Advisors LP (the "Adviser"), Baker Bros. Advisors (GP) LLC (the "Adviser GP"), Julian C. Baker, and Felix J. Baker (collectively, the "Reporting Persons"). The filing states that Baker Bros. Advisors (GP) LLC is the sole general partner of the Adviser, and that pursuant to management agreements, the Funds' general partners relinquished to the Adviser "all discretion and authority with respect to the investment and voting power of the securities held by the Funds." The two funds named in the filing are Baker Brothers Life Sciences, L.P. and 667, L.P.

Madrigal Pharmaceuticals, Inc. (NASDAQ:MDGL) is a pharmaceutical company whose principal executive offices are located at 1001 Conshohocken State Road, Suite 2-350, West Conshohocken, Pennsylvania, 19428, as stated in the filing. The common stock subject to this disclosure carries a par value of $0.0001 per share and is identified by CUSIP number 558868105. The 9.99% ownership calculation incorporates both the 90,417 Prefunded Warrants, which are subject to limitations on exercise described in the filing, and 4,790 vested non-qualified stock options received by Julian C. Baker and Dr. Raymond Cheong, a full-time employee of the Adviser, as compensation for their service on the issuer's board.

The filing notes that the reporting persons may, depending on their continuing assessments of factors including business prospects, stock market conditions, and board and management actions, acquire additional securities through open market purchases, privately negotiated purchases, conversion of Convertible Preferred shares, or exercise of Prefunded Warrants, or may dispose of securities under their control. The filing also states that the reporting persons may discuss items of mutual interest with the issuer's management, board members, and other investors.

What Was Disclosed

Baker Bros. Advisors LP and three affiliated reporting persons disclosed aggregate beneficial ownership of 2,330,144 shares, equal to 9.99%, of Madrigal Pharmaceuticals, Inc. common stock as of November 6, 2026, following acquisitions that produced a greater-than-1-percent change in beneficial ownership.