Edgewood Oncology Doses First Two Patients in Phase IIa Study for BTX-A51, a Potential Treatment for Metastatic Breast Cancer

Image Credit: Adobe Stock Images/Oksana Smyshliaeva

Edgewood Oncology announced that it has begun dosing patients as part of a Phase IIa clinical trial of BTX-A51, targeting metastatic breast cancer. According to the company, the treatment is a kinase inhibitor that focuses on estrogen receptor positive/human epidermal growth factor receptor 2 negative (ER+/HER2-) cases, addressing GATA3 mutations. Edgewood describes GATA3 as a protein that helps maintain healthy breast cells. However, 15% of breast cancer cases present mutations in the protein, which is connected to shorter progression free (PFS) and overall survival (OS).¹

“This represents an important milestone for both Edgewood Oncology and for patients with ER+/HER2- breast cancer, particularly those with a GATA3 mutation, who need better treatment options targeted to their underlying mutation profile,” said Zung L. Thai, MD, PhD, chief medical officer, Edgewood Oncology, in a press release. “Moreover, while CDK4/6 inhibitors remain a cornerstone of current treatment regimens, resistance to these therapies poses a formidable challenge. By targeting CDK7 and CDK9, key regulators of cell cycle progression, BTX-A51 not only aims to circumvent this resistance but also to transform the treatment landscape.” “This represents an important milestone for both Edgewood Oncology and for patients with ER+/HER2- breast cancer, particularly those with a GATA3 mutation, who need better treatment options targeted to their underlying mutation profile,” said Zung L. Thai, M.D., Ph.D., chief medical officer of Edgewood Oncology. “Moreover, while CDK4/6 inhibitors remain a cornerstone of current treatment regimens, resistance to these therapies poses a formidable challenge. By targeting CDK7 and CDK9, key regulators of cell cycle progression, BTX-A51 not only aims to circumvent this resistance but also to transform the treatment landscape.”

In April, Edgewood also revealed positive data from a study of BTX-A51 in human liposarcoma (LPS). Reportedly, the treatment demonstrated significant efficacy in patient-derived LPS cell lines and xenograft models, reduced MDM2 overexpression, and was well tolerated in preclinical models. Liposarcomas are defined as amplification of the mouse double minute 2 homolog (MDM2) gene, which leads to destruction of the normal p53.²

“We’re pleased that investigators at Dana-Farber have taken an interest in BTX-A51, which is currently being evaluated in a Phase 2 combination study with azacitidine in patients with relapsed or refractory (R/R) AML,” said David N. Cook, PhD, CEO, Edgewood Oncology, in a press release. “These data also suggest the potential for BTX-A51 in cancers with MDM2 amplifications, a group of genetically defined tumors that span multiple tissue types suggesting broader potential.”

Edgewood first acquired the BTX-A51 program in 2023. Additionally, it completed a round of Series A funding backed by Alta Partners to advance the clinical development of BTX-A51 in acute myeloid leukemia (AML) and as a precision medicine approach to breast cancer.³

“We formed Edgewood Oncology because of the synergistic mechanism of action and promising safety and anti-tumor data that was observed with BTX-A51 in Phase I in AML and solid tumor patients. We look forward to further developing this compound using a precision medicine approach in patient populations who lack effective treatment options,” said Cook, in a press release. “Furthermore, we have taken a virtual approach to drug development, which allows us to remain highly focused, agile and efficient as we advance this investigational compound in the clinic.”

References

1. Edgewood Oncology Announces First Patients Dosed in Phase 2a Study of BTX-A51 in Genetically-Defined Breast Cancer. Edgewood Oncology. May 21, 2024. Accessed May 22, 2024. https://www.edgewoodoncology.com/news/edgewood-oncology-announces-first-patients-dosed-in-phase-2a-study-of-btx-a51-in-genetically-defined-breast-cancer

2. Edgewood Oncology Announces Positive Efficacy Data From Investigator-Sponsored Study of BTX-A51 in Preclinical Models of Liposarcoma. Edgewood Oncology. April 8, 2024. Accessed May 22, 2024. https://www.edgewoodoncology.com/news/edgewood-oncology-announces-positive-efficacy-data-from-investigator-sponsored-study-of-btx-a51-in-preclinical-models-of-liposarcoma-1

3. Edgewood Oncology Emerges From Stealth with $20 Million in Series A Financing to Advance BTX-A51 in Patients with Hematologic Malignancies and Genetically-Defined Solid Tumors. Edgewood Oncology. March 25, 2024. Accessed May 22, 2024. https://www.edgewoodoncology.com/news/edgewood-oncology-emerges-from-stealth-with-20-million-in-series-a-financing-to-advance-btx-a51-in-patients-with-hematologic-malignancies-and-genetically-defined-solid-tumorsnbsp