Is “Rescuing Failed Drugs with AI” a Category Now?

Inside the growing bet that AI can find the patients pharma's failed trials missed...

Update (October 2026): Five months after this piece was first published, Biossil raised another $153 million (C$216 million) at a $1 billion valuation, this time led by the OpenAI Startup Fund. We have updated the Biossil profile below accordingly.

In April, a Toronto-based startup called Biossil came out of stealth with a total of $70 million in funding, co-led by Peter Thiel's Founders Fund and OpenAI. In late September, it followed up with a $153 million round at a $1 billion valuation, led by the OpenAI Startup Fund.

Their thesis is a bit different from what most AI biopharma companies are doing. Instead of designing new molecules, Biossil uses AI to dig through late-stage clinical failures and figure out which patient subgroups those drugs should have actually been tested on. Ten molecules were acquired while in stealth mode over three years. Trials running in everything from glioblastoma to Alzheimer’s.

That’s not drug repurposing in the classic sense — taking an approved drug and finding it a new indication, like thalidomide going from its original (disastrous) use to multiple myeloma, or metformin being studied in cancer.

Biossil is doing something more subtle: same molecule, same disease, just a more precisely defined subset of patients. The argument is that many drugs “failed” trials only in the “aggregate”, averaged across a heterogeneous population where a real signal got buried.

And they’re not alone. A cluster of companies, each with different technical approaches and varying levels of clinical evidence, is converging on a shared conviction: the pharma industry’s 90%+ clinical failure rate isn’t just a scientific problem. It’s partly an analytical one. The tools to find the right patients simply weren’t good enough, until now.

This is a piece about that convergence. We’ll map who’s doing what, how the approaches differ, what’s actually been validated, and whether the thesis holds up under scrutiny.

In this issue: The Logic of Drug Rescue — The Landscape: Who’s Doing What — A Closer Look at the Frontrunners — The Roivant Precedent — What Doesn’t Work (Yet) — Looking Ahead