Atossa Therapeutics Inc (NASDAQ: ATOS) presented preclinical research data on its drug candidate (Z)-endoxifen for Duchenne muscular dystrophy at the MDA Clinical & Scientific Conference on March 11, 2026, in Orlando, Florida.

The study used mdx5Cv dystrophic mice, a standard model for Duchenne muscular dystrophy research. Results showed that (Z)-endoxifen improved muscle strength and motor performance in both juvenile and adult dystrophic mice. The treatment enhanced resistance to contraction-induced muscle injury and produced favorable changes in body composition, including increased lean mass and reduced fat mass.

Key biochemical and histologic markers of muscle damage were reduced in treated mice. The therapy was well tolerated with no adverse findings observed during the study period.

"These findings demonstrate the potential of (Z)-endoxifen to meaningfully reduce muscle damage and potentially improve muscle performance in a nonclinical model of Duchenne muscular dystrophy," said Dr. Steven C. Quay, Chairman and Chief Executive Officer of Atossa Therapeutics.

Duchenne muscular dystrophy is a progressive neuromuscular disorder caused by mutations in the dystrophin gene. Symptoms typically emerge in early childhood and include progressive muscle weakness, loss of ambulation, respiratory compromise, and cardiomyopathy. The condition is fatal, often in early adulthood.

(Z)-endoxifen is a selective estrogen receptor modulator/degrader that Atossa is evaluating for applications in oncology and rare diseases. The company's proprietary oral formulation has shown a favorable safety profile and pharmacology distinct from tamoxifen. The drug is not approved for any indication.

Atossa Therapeutics is a clinical-stage biopharmaceutical company developing therapies in oncology and other areas of unmet medical need, according to the company's press release.