Atossa Therapeutics and Quantum Leap Healthcare Announce I-SPY 2 Clinical Trial to Evaluate (Z)-Endoxifen in Combination with Abemaciclib (VERZENIO) in Women with ER+/HER2- Breast Cancer

SEATTLE, April 15, 2024 (GLOBE NEWSWIRE) -- Atossa Therapeutics, Inc. (Nasdaq: ATOS) (“Atossa” or the “Company”) and Quantum Leap Healthcare Collaborative today announced the initiation of a new study to evaluate Atossa’s proprietary (Z)-endoxifen in combination with abemaciclib (VERZENIO), a cyclin-dependent kinase (CDK) 4/6 inhibitor marketed by Eli Lilly and Company, in women with ER+/HER2- breast cancer. Atossa is a clinical stage biopharmaceutical company developing innovative medicines in areas of significant unmet medical need in oncology with a focus on breast cancer.

The new study arm will enroll approximately 20 women with newly diagnosed Estrogen Receptor positive (ER+) / Human Epidermal Growth Factor Receptor 2 negative (HER2-) invasive breast cancer. Participants will receive 40mg (Z)-endoxifen once daily in combination with 150mg abemaciclib twice daily for a total of 24 weeks prior to surgery.

“Endocrine therapy in combination with CDK 4/6 inhibition is a widely used treatment for patients with advanced-stage ER+ breast cancer and as an adjuvant therapy for node positive, hormone positive early-stage disease, found at the time of surgical resection,” said Dr. Laura Esserman, director of the University of California San Francisco Breast Care Center and founder of Quantum Leap Healthcare Collaborative. “Women with high clinical stage but less proliferative tumors (molecularly low risk or those with late recurrence risk) are challenging to treat. Late recurrence is high regardless of either endocrine or chemotherapy. Thus, we are looking for new combined treatments, which can be used in the pre-surgery (neoadjuvant) setting. We look forward to learning more about the potential of (Z)-endoxifen in combination with abemaciclib in the neoadjuvant setting in the I-SPY TRIAL.”

The new study arm evaluating (Z)-endoxifen in combination with abemaciclib is part of the ongoing I-SPY 2 Endocrine Optimization Pilot Protocol (EOP), which targets patients with newly diagnosed estrogen receptor-positive (ER+) invasive breast cancer whose tumors are predicted to be sensitive to endocrine therapy but for whom chemotherapy is expected to provide little or no benefit. These patients have substantial risk for recurrence, often after five years, and need novel treatments that address the risk of recurrence and are more effective and tolerable than the current standard of care.