Atossa Therapeutics Unveils Promising Results from Endoxifen Trial Marking Milestone in Breast Cancer Risk Reduction

Breakthrough Findings from Atossa Therapeutics on Endoxifen

Atossa Therapeutics, Inc., a prominent clinical-stage biopharmaceutical company, has revealed groundbreaking results from their KARISMA trial published in the Journal of the National Cancer Institute. This innovative study focused on the use of (Z)-endoxifen, a selective estrogen receptor modulator, to reduce mammographic breast density (MBD) in healthy premenopausal women—an important indicator of breast cancer risk.

The trial was a randomized, double-blind, placebo-controlled Phase 2 study involving 240 participants, all healthy premenopausal women aged 40 to 55, drawn from Sweden’s national mammography screening program. Over six months, participants were administered daily doses of either a placebo, 1 mg, or 2 mg of Endoxifen. The objective was clear: to assess the efficacy of Endoxifen in reducing MBD, a well-known risk factor for breast cancer.

The findings were impressive, showcasing a statistically significant reduction in MBD. The 1 mg dose achieved a 19.3% reduction in MBD compared to placebo, while the 2 mg dose resulted in a 26.5% reduction. Notably, these results rivaled those observed with standard-dose tamoxifen, accomplished through the direct administration of Endoxifen, the most active metabolite of tamoxifen.

One of the compelling aspects of this study was the favorable tolerability observed with the 1 mg dose. With a profile akin to placebo, this low dose appears to strike a balance between efficacy and patient comfort, making it a strong candidate for further development in women at elevated risk for breast cancer. In contrast, the 2 mg dose saw more notable adverse events, hinting that lower doses may offer a superior safety profile.

Dr. Steven Quay, the President and CEO of Atossa Therapeutics, expressed the significance of these results. “Tamoxifen has been an approved option for breast cancer risk reduction, yet its uptake has been hindered by tolerability issues. By administering Endoxifen directly, we stand to capture the benefits while enhancing predictability and comfort for patients,” Dr. Quay stated.

Moreover, the study shed light on the dose-selection aspect of Endoxifen. Participants showed significant MBD reduction at lower plasma concentrations of Endoxifen, reaching around a 20% decrease at plasma concentrations of roughly 3–4 ng/mL. This insight could drive the selection of 1 mg as an optimal dose for future studies focused on breast cancer prevention.

Furthermore, while the tolerability of the 1 mg dose proved to be comparable to placebo, the incidence of adverse events remained predominantly mild and consistent with responses typically seen in tamoxifen administration.

Atossa aims to leverage these promising results to advocate for Endoxifen as a viable option for women at heightened risk of breast cancer. This clinical trial represents a significant shift towards improved preventive strategies in oncology—a field where hormones and metabolic profiles can greatly influence treatment efficacy.

To conclude, this trial not only strengthens the rationale for advancing Endoxifen in the clinical arena but also addresses a substantial gap in the options available for women hesitant about existing therapies. The positive findings from the KARISMA Endoxifen trial could be a stepping stone towards enhancing preventive healthcare for women worldwide.

Through continued research and development, Atossa Therapeutics and its promising lead candidate can reshape the landscape of breast cancer risk management. As the quest for innovative therapies continues, Atossa stands at the forefront, potentially paving the way for more accessible and effective solutions in breast cancer prevention.