FDA grants Breakthrough Device status to Primaa's Cleo Skin AI for skin cancer pathology

The U.S. Food and Drug Administration granted Breakthrough Device Designation to Cleo Skin, Primaa's artificial-intelligence tool for helping pathologists read digitized skin biopsies and excisions, according to Clinical Lab Products and The Dermatology Digest coverage of a company news release on Friday, Nov. 6, 2026 — a regulatory fast lane that is not the same as U.S. marketing authorization.

Skin biopsy volume is rising and pathologist time is not. Cleo Skin's bet is a background second reader that flags melanoma suspects and hands you a mitosis gallery sorted by probability — useful if the numbers hold up outside the study set. Breakthrough is a conversation ticket with FDA, not a green light to sell in U.S. clinics. Europe already CE-marked it; the U.S. still has to clear it.

The U.S. Food and Drug Administration granted Breakthrough Device Designation to Cleo Skin, an artificial-intelligence tool from Paris-based Primaa. It helps pathologists diagnose skin cancers from digitized biopsy slides and excised tissue. A Breakthrough Device Designation puts a company in a faster line for talks with the agency before it files to sell the device in the United States. It is not permission to market the device here. Those lines are Primaa's, as carried by Clinical Lab Products on Nov. 6, 2026. A 510(k), a De Novo, and a PMA are separate paths that clear a device for sale. This designation is none of those.

Cleo Skin already holds CE-IVDR certification in Europe, received in March 2026. CE-IVDR is the European mark for a lab test used to diagnose disease. Clinical Lab Products, covering the company release, says Cleo Skin is the first AI tool in dermatopathology to hold both that European mark and an FDA Breakthrough Device Designation. Dermatopathology is the work of reading skin under a microscope, or on a scan of that slide. The Dermatology Digest describes the tool as already used in Europe. Neither outlet gives a count of U.S. labs, and the designation is not a U.S. sale.

Cleo Skin reads whole-slide images, the full digital scan of a glass slide, from skin biopsies and excisions. It flags areas that look suspicious for melanoma. It offers indicative lesion classifications, a suggested label rather than the pathologist's final call, including basal cell carcinoma, squamous cell carcinoma, and nevus. A nevus is a mole. It also suggests measurements a pathologist already makes: margins, how far the tumor sits from the cut edge; Breslow thickness, how deep a melanoma goes; and mitotic regions, places where cells are dividing. It is built to plug into the image system a lab already uses, and to support the pathologist, not replace them. Those lines are Primaa's.

SkinPerf2026 is a multicenter study in Europe. Sixteen pathologists at 11 French institutions read 313 whole-slide images. With Cleo Skin, overall melanoma sensitivity rose from 83.8% to 88.6%. Sensitivity, here, is how often a real melanoma gets caught. Among junior pathologists, melanoma sensitivity rose from 79.7% to 88.2%. The median time to find a mitosis dropped by 24%. A median is the middle case, so half the reads were faster and half were slower. Those figures are from the study, as the company reported them.

An exploratory U.S. evaluation with PathPresenter put Cleo Skin inside the viewer seven pathologists already use. They reviewed 75 whole-slide images. Analysis time fell by 20%. Among junior pathologists, diagnostic sensitivity rose by 17%. Exploratory means a smaller look, not the study a company would hand the FDA as proof it can sell the device. Those figures are from that evaluation, as the coverage reported them.

Hugo Watel, chief operating officer of Primaa, said in the release as carried by Clinical Lab Products: "Receiving the Breakthrough Device Designation is a strong recognition of our mission: to support every pathologist with reliable assistance on every case. Cleo Skin was built with pathologists, for pathologists, and in Europe, where it is already CE-IVDR marked, they rely on it to work faster and with more confidence, whatever their level of experience. We look forward to working closely with the FDA through the Breakthrough Devices Program to bring this support to US pathologists, who face the same growing pressure on skin biopsy volumes." That quotation is his.

Wonwoo Shon, director of dermatopathology services at Cedars-Sinai Medical Center and founder of Aimes Diagnostics, said in the release: "Mitotic counting remains an important but time-consuming part of melanoma assessment. What is particularly useful about Cleo Skin is that its gallery-based mitosis detection can transform this repetitive search into a more focused and efficient review. This is a practical example of how AI can support, not replace, the pathologist by streamlining routine tasks and allowing greater attention to findings that require expert judgment." That quotation is his.

Primaa says it will use the Breakthrough Devices Program to keep talking with the FDA while it prepares a formal submission for U.S. marketing clearance. That plan is the company's. The designation itself is not the clearance.

The picture is Cleo Skin's screen on a skin-biopsy slide: green marks on the tissue, a box and circle on the region under review, and a gallery of dark mitotic candidates sorted by probability. The credit is Primaa, via Clinical Lab Products.

In plain terms, the FDA moved a Paris skin-slide reader to the front of the conversation line. That is not a clearance to sell it to American labs. Europe already put a CE-IVDR mark on it in March 2026. The French study is 313 slides and 16 pathologists. The U.S. look is 75 slides and seven people. Those are not the same bar.