Biossil Hits $1B Valuation with $153M OpenAI-Led Round

For biotech investors, Biossil's three-year progression from $3.7M seed to a $1B valuation is a case study in capital-efficient, AI-driven drug repurposing. The new round's terms are telling: preferred shares issued at $28.69, triple last year's price, signal strong investor conviction in a model that acquires shelved drug candidates rather than pursuing de novo discovery.

The key development in this cluster is a reported US$153-million all-equity venture financing of Toronto-based Biossil Inc., led by OpenAI through its OpenAI Startup Fund, which values the three-year-old company at US$1-billion. The Globe and Mail reported the round based on a source familiar with the matter who was not authorized to speak publicly; Biossil chief executive officer Anthony Mouchantaf declined to comment, and neither Biossil nor OpenAI has announced the deal. According to the report, OpenAI's Startup Fund supplied the majority of the capital, while existing investors including Founders Fund, Quiet Capital, Modern Capital, Golden Ventures, Panache Ventures, Duke University's endowment fund and the Abu Dhabi Investment Council participated. A small portion of the equity proceeds is earmarked for early employees, adding a secondary-liquidity element to the raise.

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The financing history shows rapid escalation: a $3.7-million seed led by Staircase Ventures in 2023; a US$22-million round led by Founders Fund in 2024; and a US$43-million round co-led by OpenAI and Founders Fund about a year ago.

Biossil was founded in 2023 by Anthony Mouchantaf, a former head of RBC's venture capital investment strategy, and Alexander Mosa, who holds both an MD and a PhD in virology and trained at the University Health Network. The company uses artificial intelligence to identify and redevelop failed drug candidates—molecules that were shelved for reasons other than safety—for new or previously pursued indications. The financing history shows rapid escalation: a $3.7-million seed led by Staircase Ventures in 2023; a US$22-million round led by Founders Fund in 2024; and a US$43-million round co-led by OpenAI and Founders Fund about a year ago. The latest round, at US$153-million, is roughly 3.6 times larger than the prior financing. An August filing with Corporations Canada added a new class of 5.37 million preferred shares valued at US$28.69 each, triple the value of shares issued in last year's financing, providing documentary corroboration for a step-up in valuation.

The investment underscores growing institutional and strategic interest in applying AI to drug repurposing and rescue. Unlike de novo AI drug discovery, which must identify novel molecules and then prove their safety from scratch, Biossil's approach starts with compounds that often have existing preclinical or clinical safety data, potentially reducing cost, time and regulatory risk. This is especially relevant in an environment where late-stage clinical failure remains the dominant cause of pharmaceutical R&D write-offs. By buying rights to deprioritized assets, Biossil aims to create a portfolio of therapies with clearer development paths—though the company still must validate efficacy and navigate regulatory requirements. OpenAI's role is more than symbolic: its Startup Fund has now backed Biossil in consecutive rounds, suggesting a strategic commitment to demonstrating generative and machine-learning models in a highly regulated, high-value vertical. For OpenAI, successful drug resurrection would validate its technology beyond software and into biology, while giving it exposure to a multi-billion-dollar therapeutic market.