Atossa Therapeutics, Inc. and Quantum Leap Healthcare Collaborative 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. 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.

Under the terms of the study agreement, Quantum Leap will conduct the study with Atossa and Eli Lilly and Company each responsible for supplying their respective study drugs.