Bristol Myers Squibb Leads Pathos AI's $237 Million Series E at About $3 Billion, Alongside an Alzheimer's Data Deal With Tempus
Pathos AI, a New York company that uses AI agents to steer drug development, closed a $237 million Series E led by Bristol Myers Squibb at a post-money valuation of about $3 billion. The same day, it announced collaborations under which Tempus AI will build a neurology dataset that Pathos will license for $55 million over five years, and BMS will get access to Pathos's Foundry platform, including three-year exclusive rights in neuroscience.
A large drugmaker leading the round, and taking platform access at the same time, makes this as much a commercial deal as a financing, and it gives Pathos AI's claim that AI agents can raise drug-development success rates a paying test in neuroscience. On Friday, October 23, Pathos said it had closed a $237 million Series E at a post-money valuation of about $3 billion, led by Bristol Myers Squibb (BMS) with participation from existing investors.
What the money is for
Pathos says the proceeds will scale its AI platform, Foundry, and advance its clinical pipeline, which it says now has four active clinical assets. It names as a key priority a TROP2/HER3 bispecific antibody-drug conjugate that it wants to move toward registrational studies. Fierce Biotech reported that Pathos licensed that drug from Alphamab Oncology. Pathos also lists pocenbrodib in prostate cancer and multiple myeloma, AZD4241, an estrogen-receptor PROTAC partnered with AstraZeneca, and DO-2, a MET kinase inhibitor.
Pathos says Foundry "operates via thousands of specialized AI agents" that pull together clinical, genomic and competitive data on a drug program and identify the next decision for it. "We are building a platform to systematically improve the probability of success in drug development," CEO Iker Huerga said in the release.
The BMS and Tempus deals
In a separate announcement the same day, Pathos said Tempus AI will build a de-identified, longitudinal dataset from hundreds of thousands of patients with neurological conditions, which Pathos will license under a five-year, $55 million agreement. Pathos says it will use Foundry on that data to test hypotheses about disease biology and design more targeted clinical trials, starting with Alzheimer's disease.
BMS gets non-exclusive access to Foundry across its broader portfolio, plus three-year exclusive rights to use it in support of its neuroscience programs, according to Pathos. "Our investment in Pathos reflects our commitment to applying advanced AI and data science across research and development," said Simon Davies, BMS's head of data and quantitative sciences.
Fierce Biotech reported that the round follows a $365 million Series D in May 2025 and a $62 million Series C in October 2024.
Limits
- Pathos did not disclose the other investors in the round or the financial terms of the BMS collaboration.
- Claims about Foundry's effect on success rates are Pathos's own; the company has not published outcome data showing that its AI-steered programs succeed more often.
- We have left out the antibody-drug conjugate's code name: Pathos's release spells it two ways, and Fierce Biotech uses a third version.
- Fierce Biotech describes that drug as phase 3 and the AstraZeneca-partnered PROTAC as preclinical. Pathos says it is moving the drug "toward registrational studies" and counts four clinical assets. We did not reconcile the difference.