Atossa Therapeutics and Quantum Leap Healthcare Collaborative have dosed the first patient in the I-SPY 2 Trial of the former’s (Z)-endoxifen, along with abemaciclib (VERZENIO), for breast cancer treatment.

The study is part of the I-SPY 2 Endocrine Optimization Pilot Protocol (EOP) that is currently underway and aims to assess the efficacy of (Z)-endoxifen, a potent Selective Estrogen Receptor Modulator (SERM).

Atossa president and CEO Dr Steven Quay said: “The innovative idea of combining (Z)-endoxifen and abemaciclib in the neoadjuvant setting can open the door to the development of gentler, more patient-friendly treatment options for women with invasive breast tumours.

“By combining these therapies, we hope to achieve improved outcomes compared to available therapies, not only in terms of safety and efficacy but also with respect to patients’ quality of life outcome measures.”

Abemaciclib is a cyclin-dependent kinase (CDK) 4/6 inhibitor, which is marketed by Eli Lilly and Company as a neoadjuvant treatment for newly diagnosed estrogen receptor-positive (ER+)/human epidermal growth factor receptor 2 negative (HER2-) breast cancer in women.

As part of the study, approximately 80 participants will be enrolled across two cohorts, each with 40 participants, including both premenopausal and postmenopausal women.

The participants will be treated with 80mg of (Z)-endoxifen once a day and 150mg of abemaciclib twice daily for 24 weeks before surgery. The second cohort will also receive ovarian function suppression to evaluate its impact.

The anticipated data from the study, expected in 2026, will contribute to the evidence supporting the safety and efficacy of (Z)-endoxifen in treating breast cancer.

Atossa and Eli Lilly are responsible for supplying their respective study drugs under the terms of the study agreement.

In June 2023, Atossa Therapeutics completed enrolment of a pharmacokinetic (PK) run-in cohort in its Phase II trial of (Z)-endoxifen and exemestane with goserelin.