AI-designed bacteriophages are given to a patient for the first time, Radical Numerics says

Radical Numerics, a San Francisco company developing AI models for biology, said that bacteriophages designed by its genome language model Omnii-1 had been administered to a human patient with an antibiotic-resistant bacterial infection. It described this as the world’s first clinical use of AI-designed phages. The treatment was given under an “authorized, physician-led compassionate-use pathway”, which allows investigational therapies outside clinical trials when no satisfactory alternative exists.

Phages are viruses that infect bacteria, and phage therapy is a long-standing candidate for infections that antibiotics no longer clear. Finding a phage that matches a particular patient’s strain is the difficult part. Radical Numerics said Omnii-1, pretrained on genomic data and then trained on phage genomes, can generate phage variants and rank them by predicted activity against specific strains. In its write-up, 69.9% of designed T7 tail-fibre variants with 11 to 15 amino-acid changes were recovered in the lab, against 4.8% of random controls. For host prediction on randomly held-out E. coli strains, its top two recommendations included a biologically active phage for 92.1% of eligible strains. These are the company’s own results.

For the patient, the company said only that the cocktail containing Omnii-1-designed variants “eliminated the patient’s antibiotic-resistant isolate in vitro” before being administered. It is not disclosing the clinical course or outcome, citing the risk that even limited detail could identify the patient, and says observations from a single patient “cannot establish general safety or efficacy”. The infection is not named. The Register noted that the company did not respond to its questions and that the write-up does not say which infection the patient had.

The “first” is the company’s own claim, and the coverage so far, which is one trade-press report, does not test it. The Register pointed to earlier AI-designed phage work from Stanford University and the Arc Institute, which was laboratory research against E. coli and not a treatment. Because no outcome has been reported, the announcement shows that AI-designed phages have reached a patient, not that they helped one.

Radical Numerics released the work alongside Omnii-1 itself, a model it says was pretrained across 28 biological modalities, with eight applications beyond phage design. It said it hopes to build a systematic process for designing phages against individual infections, and invited clinical partners to supply bacterial isolates.