Atossa Therapeutics Inc (NASDAQ:ATOS), which is developing medicines aimed at oncology and breast cancer, revealed that six patients have been dosed with its proprietary selective estrogen receptor modulator (SERM), (Z)-endoxifen, in the ongoing Phase 2 I-SPY 2 clinical trial.
The Seattle-based clinical-stage biopharma company said (Z)-endoxifen is being evaluated as a neoadjuvant treatment for 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.
The I-SPY 2 trial is a collaborative effort among academic investigators from US cancer research centers, Quantum Leap Healthcare Collaborative, the US Food and Drug Administration (FDA), and the Foundation for the National Institutes of Health Cancer Biomarkers Consortium.
The (Z)-endoxifen treatment arm, which is expected to enroll 20 patients, is part of the I-SPY 2 endocrine optimization pilot protocol (EOP). Patients will receive 10 mg of (Z)-endoxifen daily for up to 24 weeks before surgery. Currently, there are 41 I-SPY 2 sites, all of which have the EOP program open.
"Reaching 30% enrollment in the I-SPY 2 study is another important milestone in our ambitious (Z)-endoxifen development program," said Atossa CEO Dr Steven Quay.
"These patients have substantial risk for recurrence and need novel treatments options that are more tolerable and more efficacious than currently approved drugs. (Z)-endoxifen has the potential to slow the progression of ER-positive breast cancer in the neoadjuvant setting, making surgery more effective and reducing the risk of recurrence.”
Dr Steven Quay said Atossa is looking forward to seeing data from the trial, which along with data from its Phase 2 EVANGELINE trial, will “inform conversations with the FDA” and the company’s planned Phase 3 protocol.
Dr Laura Esserman of the University of California San Francisco, who is the founder and leader of the I-SPY trial, noted that they were focused on optimizing treatments for the fast-growing breast cancers.
“One of the biggest challenges in breast cancer is the hormone positive breast cancers that are slow growing. They can recur for up to 15 years or more, and we urgently need to find predictors of response so that we can prevent late recurrence,” said Dr Esserman.
“We know that women suffer from the side effects of years of extended endocrine therapy…So, we have a great need to find more effective and more tolerable agents so that women with live longer and better. The goal of the endocrine optimization pilot is to test these new and exciting hormone directed therapies like endoxifen.”
Premenopausal patients with breast cancer
Breast cancer is the most frequently diagnosed cancer in premenopausal women worldwide and accounts for almost half of the cancers that occur in women aged between 15-to-49, according to the company.
Ovarian function suppression, when combined with either tamoxifen or an aromatase inhibitor, is the standard of care for the endocrine management of stage 2 and 3 premenopausal ER+/HER2- breast cancer. The I SPY EOP specifically targets women of all ages with molecularly low risk stage 2 and 3 breast cancer.
Atossa said (Z)-endoxifen is the most active metabolite of the FDA-approved selective estrogen receptor modulator tamoxifen. Studies have shown that the therapeutic effects of tamoxifen are driven in a concentration-dependent manner by (Z)-endoxifen. Atossa is developing a proprietary oral formulation of (Z)-endoxifen that doesn’t require liver metabolism and is encapsulated to bypass the stomach as acidic conditions in the stomach convert a greater proportion of (Z)-endoxifen to the inactive (E)-endoxifen.
Contact the author Uttara Choudhury at uttara@proactiveinvestors.com
Follow her on Twitter: @UttaraProactive