Response of a chemo-resistant triple-negative breast cancer patient to a combination of p62-encoding plasmid, Elenagen, and CMF chemotherapy

Triple-negative breast cancers are often characterized by aggressive behavior and short clinical course once they become chemotherapy-resistant. We describe below a patient who has shown a response to combination of chemotherapy with Elenagen, a plasmid encoding p62. Elenagen was tested in a previous phase I/II study in patients with refractory solid tumors and shown to be safe. Also, plasmid ability to halt tumor progression and restore sensitivity to chemotherapy was found. Preclinical data supports effects on tumor grade and change the tumor’s microenvironment in spontaneous canine breast cancers. We describe here a 48-year old female with triple-negative and BRCA1/2-negative breast cancer who had a primary resistance to chemotherapy and negative dynamics despite the use of multiple lines of treatments. Elenagen was applied intramuscularly at a dose of 1 mg weekly in combination with standard chemotherapy scheme CMF (cyclophosphamide, methotrexate, fluorouracil). In this patient we observed partial tumor regression (by 33%) and 19 weeks of progression-free survival. This first observed objective response to a combination of Elenagen with chemotherapy demonstrates that even in heavily pretreated chemo-resistant triple-negative tumor, the addition of Elenagen to a chemotherapy regimen can cause an objective response and increase in progression-free survival. Such a regimen is worthy of further study in a larger number of patients.