Azitra reports ex vivo skin data for its filaggrin cosmetic ingredient

Azitra, Inc. (NYSE American: AZTR) reported on July 15, 2026 the results of two separate ex vivo human skin tissue studies of its ATR-COSF program. The release, filed with the Securities and Exchange Commission as Exhibit 99.1 to a Form 8-K, says the studies measured how far a recombinant filaggrin domain penetrates the skin and whether the formulation changes skin elasticity. ATR-COSF is a supernatant from a strain of S. epidermidis engineered to secrete a functional unit of the human filaggrin protein.

The penetration study

The first study used fresh, healthy human skin explants. The skin was first stimulated with TH2 cytokines to lower native filaggrin levels. The test product was a 2% lyophilized supernatant in a hydrogel. According to the release, penetration into the middle to lower stratum corneum was detected after a single application, and increased amounts appeared with more applications. After three applications, the protein reached the stratum granulosum.

Standardized safety testing found the 2% formulation non-irritating and non-corrosive to the skin and eyes, the release says.

The elasticity study

The second study used defatted human skin explants and measured elasticity 20 hours after application. Concentrations of the lyophilized supernatant in the hydrogel ranged from 0.0% to 7.5% weight by weight. The lowest active level, 0.09% w/w, gave a 1.6-fold increase in elasticity, and the highest, 7.5% w/w, gave a 4.4-fold increase. Hydrogels containing 0.28% w/w of the active ingredient restored ex vivo abdominoplasty skin elasticity to values historically observed in healthy skin. In the pictured sample, the 0.3% w/w hydrogel gave approximately two times the elasticity of placebo-treated skin.

What the data show and what comes next

These are laboratory results in excised skin samples, not studies in people. The release gives no p-values, no sample sizes and no donor numbers, and the roughly twofold elasticity comparison comes from one pictured sample. The return to healthy-skin elasticity is measured against values historically observed, not a matched control. Salva said, "Our plan is to continue to optimize our formulations and test on additional ex vivo human wrinkle models as we head towards starting our human study." The release gives no date for that study. ATR-COSF is a cosmetic ingredient program, and the company has no product revenue to show for it: it reported none for 2025, a net loss of $11.0 million and cash used in operations of $11.2 million. Cash and cash equivalents were $6.7 million at June 30, 2026.

The company and its pipeline

Azitra was formed as a Delaware corporation on January 2, 2014. Its annual report for 2025 describes a platform built on a microbial library of approximately 1,500 unique bacterial strains, with artificial intelligence and machine learning tools that screen the library for drug like molecules. The company says it has not commenced commercial operations.

Its lead program, ATR-12, is a genetically modified strain of S. epidermidis for Netherton syndrome, a rare, chronic skin disease, and ATR-04 targets the rash that cancer patients experience on EGFR inhibitor therapy. ATR-01, aimed at ichthyosis vulgaris, is in IND-enabling studies in 2026.

Financial position

The annual report filed February 27, 2026 shows no revenue for 2025, compared with $7,500 in 2024. Research and development expense was $4.8 million in 2025 and $4.7 million in 2024. The net loss was $11.0 million in 2025 and $9.0 million in 2024. Cash used in operations was $11.2 million in 2025 and $10.2 million in 2024. Year-end 2024 cash and cash equivalents were $4.6 million. The release does not include financial results.

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