FDA fast-tracks AI tool that helps pathologists spot melanoma on biopsy slides
Cleo Skin, already used in European labs, gets FDA Breakthrough Device status as it heads toward a US clearance bid — early data show it helps less-experienced pathologists most.
What happened: The FDA granted Breakthrough Device Designation to Cleo Skin, an AI tool made by French company Primaa that helps pathologists read skin biopsy slides for cancer. The designation isn't approval to sell the device in the US — it gives Primaa faster, more frequent access to FDA staff as it prepares a formal submission. Cleo Skin already carries CE-IVDR certification in Europe, granted in March 2026, and is in use at European pathology labs.
Why it matters: Melanoma is projected to cause roughly 234,680 new US cases in 2026, and every one of those diagnoses depends on a pathologist manually examining tissue under time pressure, often amid staffing shortages. Tools that catch suspicious areas faster, or catch things a rushed or less-experienced reader might miss, could mean fewer missed cancers and shorter waits for biopsy results — without needing more pathologists on staff, which is a real bottleneck right now.
How it works, plainly: Cleo Skin scans digitized whole slide images of skin biopsies and excisions, flags regions suspicious for melanoma, suggests a lesion type (melanoma, basal cell carcinoma, squamous cell carcinoma, or nevus), and proposes measurements pathologists need anyway, like tumor margins, Breslow thickness, and mitosis counts. It plugs into the lab software pathologists already use and is built to sit alongside a human reader's judgment, not override it.
The rollout: In a French multicenter study of 313 slides, Cleo Skin lifted overall melanoma detection sensitivity from 83.8% to 88.6%, with junior pathologists improving the most, from 79.7% to 88.2%, closing the gap with senior colleagues; mitosis-detection time fell 24%. A smaller US pilot with seven pathologists and 75 slides found a 20% cut in analysis time and a 17% sensitivity gain for junior readers. Primaa will now use the breakthrough pathway to negotiate its US clearance submission.