Biotech Portfolio in Limbo as Court Removes $1.5B Fund Chief

A pivotal ruling from a Cayman Islands court has stripped Seth Harrison, a partner at biotech-focused venture firm Apple Tree Partners (ATP), of his oversight of a $1.5 billion fund, adding yet another layer to a sprawling, multi-jurisdictional legal battle that already spans Delaware, the Cayman Islands, and a U.S. bankruptcy court. The July 14, 2026 order directs that independent officers take control of the fund’s affairs, vindicating the claims of Rigmora—the investment vehicle of Russian billionaire Dmitry Rybolovlev’s family trust—that Harrison had so mismanaged the vehicle that its foundational purpose had evaporated. The ruling is the latest salvo in a dispute that began over a decade ago when Rigmora committed up to $1.5 billion to back ATP’s biotech ventures, with capital flowing to startups like Intergalactic Therapeutics and Red Queen Therapeutics, and acquisition targets such as Akero Therapeutics. The relationship soured in 2025 when ATP sued Rigmora in the Delaware Chancery Court, alleging its primary backer had reneged on capital calls, withholding promised cash from portfolio companies. Rigmora counter-sued in the Cayman Islands, arguing ATP should be wound down. Last December, the Delaware court ordered Rigmora to pay approximately $97 million to the designated biotech companies, but it deferred to the Cayman proceedings on the question of whether the investor group had permanently lost confidence in Harrison and whether the fund had lost its core purpose. ATP promptly filed for Chapter 11 bankruptcy, a move Rigmora derided as a “delay tactic” aimed at evading Cayman oversight. The new Cayman ruling—which Rigmora said it ‘welcomed’—appoints independent directors, who have now asked the U.S. bankruptcy court to recognize their authority. However, recognition is far from assured, and the fund’s biotech portfolio hangs in the balance. The clash highlights the increasing willingness of limited partners to challenge general partners for control when relationships break down, especially in venture funds with concentrated investor bases. For the biotech startups dependent on ATP’s capital, the leadership vacuum could stall clinical programs and funding rounds. The case also underscores the complexities of cross-border fund governance, as courts in different jurisdictions grapple with overlapping issues of fiduciary duty, contract enforcement, and bankruptcy. Looking ahead, the outcome will turn on whether the U.S. bankruptcy court defers to the Cayman order or prioritizes the Chapter 11 process. If the independent directors gain control, they may seek to liquidate the fund or restructure it, potentially leaving portfolio companies scrambling for new backers. For the biotech sector, the episode is a cautionary tale about the fragility of venture funding when sovereign wealth and family office capital meets founder-led venture firms.