Atossa Therapeutics(US:ATOS)2025-06-27 12:11(Z)-endoxifen's Potential & Differentiation - (Z)-endoxifen is a novel, next-generation anti-estrogen with best-in-class potential across the breast cancer treatment paradigm[8] - (Z)-endoxifen is potentially a superior ER antagonist, being 100-fold more potent vs other SERMs, and demonstrates superior antitumor efficacy in preclinical and clinical studies[7] - (Z)-endoxifen inhibits clinically relevant ESR1 mutants, an acquired resistance mechanism to aromatase inhibitors[7] - (Z)-endoxifen has the potential to avoid current negative "on target off tissue" effects, potentially improving safety & tolerability and adherence[7] Clinical Trial Results & Regulatory Path - In a Phase II trial, CDK4/6 inhibitor-naïve patients had improved Progression-Free Survival (PFS) with (Z)-endoxifen compared to tamoxifen, with median PFS of 7.2 months versus 2.4 months, HR=0.42 (95% CI 0.22-0.80), Log rank test P=0.002[12] - The KARISMA trial showed a 17.3 percentage point reduction (p<0.01) in mammographic breast density with 1 mg of (Z)-endoxifen compared to a minimal change in the placebo group of 0.27 percentage points[13] - In an ongoing neoadjuvant clinical study, (Z)-endoxifen has demonstrated promising early efficacy with 1 CR and multiple PRs[14] Financials - The company's research and development expenses were $14.117 million in 2024, compared to $17.334 million in 2023[21] - The company's general and administrative expenses were $13.504 million in 2024, compared to $14.043 million in 2023[21] - The company's net loss was $(25.504) million in 2024, compared to $(30.094) million in 2023[21]