Biossil Raises $153M Series C+ Led by OpenAI Startup Fund to Advance Repurposed Drug Candidates

Biossil Secures $153 Million Series C+ Round

Biossil, a Toronto-based AI-native biopharma company, has raised $153 million in Series C+ funding. The round was led by OpenAI Startup Fund and included participation from Golden Ventures, Quiet Capital, Duke University, Panache Ventures, Founders Fund, Abu Dhabi Investment Council, and Modern Capital. The funding date is September 28, 2026.

Company Background

Founded in 2023 by former RBCx venture-capital director Anthony Mouchantaf and physician Alexander Mosa, Biossil uses large language models and embedding techniques to mine publicly available data on late-stage drug candidates that failed their original trials. The company then buys or licenses the most commercially promising molecules from their original owners and advances them through new clinical studies.

Biossil operates late-stage programs spanning several therapeutic areas:

• Sickle cell disease
• Idiopathic pulmonary fibrosis
• Glioblastoma
• Breast cancer
• Alzheimer's disease

AI-Driven Drug Repurposing

Biossil's approach leverages AI to identify overlooked opportunities in failed drug candidates. By analyzing vast datasets, the company aims to resurrect molecules that may have failed for reasons unrelated to efficacy—such as poor trial design or insufficient funding—and bring them back into clinical development for new indications. This strategy can reduce the time and cost typically associated with drug discovery.

Investor Syndicate

The Series C+ round attracted a diverse group of investors. OpenAI Startup Fund's participation highlights growing interest in AI applications within life sciences. Founders Fund and Abu Dhabi Investment Council bring significant capital and strategic connections. Duke University's involvement suggests academic validation and potential research collaborations. Golden Ventures, Quiet Capital, Panache Ventures, and Modern Capital round out the syndicate.

Acquisition Potential

Biossil's portfolio of late-stage programs and its AI-driven approach make it an attractive target for larger pharmaceutical companies seeking to bolster their pipelines with de-risked assets. The company's focus on repurposing failed drugs could yield cost-effective therapies, appealing to acquirers looking for near-term clinical milestones.

With $153 million in fresh capital, Biossil is well-funded to advance its programs through clinical trials. The involvement of OpenAI Startup Fund may also signal potential synergies with AI technologies that could further accelerate drug development.

Market Context

Drug repurposing has gained traction as a strategy to reduce development costs and timelines. AI-powered approaches are increasingly used to identify new uses for existing compounds. Biossil's specific focus on late-stage failures differentiates it from companies that screen broad libraries. By targeting molecules that have already undergone significant testing, Biossil may achieve faster regulatory pathways.

Conclusion

Biossil's $153 million Series C+ round, led by OpenAI Startup Fund, positions the company to advance its pipeline of repurposed drug candidates. With a strong investor syndicate and a unique AI-driven strategy, Biossil is a notable player in the AI-biopharma space. For acquirers, it represents a potential source of late-stage assets across multiple high-value therapeutic areas.