Quantum Leap Healthcare Collaborative (QLHC) announces the enrollment launch for the Re-Evaluating Conditions for Active Surveillance Suitability as Treatment: Ductal Carcinoma In Situ (RECAST DCIS), a Phase 2 platform study aimed at preventing the progression of DCIS to breast cancer. The study is evaluating three investigational endocrine therapy arms: (Z)-endoxifen, a selective estrogen receptor modulator (SERM) in development by Atossa Therapeutics (Nasdaq: ATOS); HAVAH T+Ai™, a proprietary combination of testosterone (T) and anastrozole (Ai) that targets the androgen and estrogen receptor pathways in development by Havah Therapeutics; and ORSERDU® (elacestrant), the only FDA approved oral selective estrogen receptor degrader (oSERD) in development by Stemline Therapeutics Inc. (Stemline), a wholly-owned subsidiary of the Menarini Group. 

"DCIS indicates the very earliest, noninvasive stage of the disease, that's why it is important for us to seek out alternative therapies for DCIS patients and find ways to reduce toxicity and unnecessary surgeries. We are excited to partner with three innovative companies to explore new treatments for this large and often over-treated patient population," said Laura Esserman, MD, a lead investigator for the study and founder of QLHC.

Surgery is the current standard treatment for DCIS even though many patients never progress to breast cancer, which means that patients are often over-treated with invasive procedures. This new trial, sponsored and operated by QLHC, offers DCIS patients up to six months of endocrine therapy with the intent to forego surgery and instead be monitored via long-term active surveillance, if appropriate. A key element in reducing overtreatment of DCIS is identifying biomarkers that reflect the risk of progression so that those with low-risk lesions are spared surgery. RECAST DCIS features the assessment of imaging and molecular-based biomarkers in addition to evaluating new investigational agents in this setting. The study is open to enrollment with each investigational agent arm expected to enroll up to 110 patients.

The three collaborators for this trial, Atossa Therapeutics, Havah Therapeutics, and Stemline, all aim to find alternative solutions for DCIS patients and are providing different agents for assessment.

Atossa's (Z)-endoxifen has the potential to mitigate breast cancer risk (by reducing the density of breast tissue); to reduce cancer cell activity before surgery; and to reduce the risk of recurrent or new breast cancer after the initial treatment. According to published studies, (Z)-endoxifen is a competitive inhibitor of ERα and represses ERα transcriptional activity (Z)-endoxifen is 100-fold more potent in anti-estrogen activity compared to other SERMs. (Z)-endoxifen also binds to and disrupts protein kinase C beta one function (PKCb1, a known oncogenic protein). The National Cancer Institute (NCI) and others have studied (Z)-endoxifen and have demonstrated promising results in the treatment of breast cancer as well as for the treatment of other solid tumors. Treatment with (Z)-endoxifen may avoid off target effects of tamoxifen and remaining metabolites potentially increasing adherence by improving the safety profile.

Havah Therapeutics' HAVAH T+Ai™ combines T, the natural ligand for the androgen receptior and Ai, an inhibitor of T conversion to estradiol, to modulate the growth of abnormal breast tissues. HAVAH T+Ai™ is a proprietary combination subcutaneously delivered system to overcome hormonal symptoms by balancing hormonal irregularities in the breast, developed from more than 10 years of clinical research into hormonal regulation in women. Havah has extensive clinical experience using HAVAH T+Ai™ to address pre- and postmenopausal prevention of breast disease, and the company generated data from more than 1,000 Australian women with breast disease through an ongoing open label cohort study (more than 6,200 implants), with critical safety pharmacokinetic and early efficacy data already demonstrated.

Stemline's Elacestrant (ORSERDU), was approved by the U.S. Food & Drug Administration in January 2023 for the treatment of postmenopausal women or adult men with estrogen receptor (ER)-positive, HER2-negative, ESR-1 mutated advanced or metastatic breast cancer, following at least one line of endocrine therapy.