Breast Cancer Drug, EndoTAG-1, Shows Promise in Phase II Trial
Paclitaxel/lipid combo targets blood supply to tumors (May 16)
A phase II study of neoadjuvant EndoTAG-1 (Medigene AG) — a composition of the cytostatic drug paclitaxel combined with neutral and positive lipids — has met its primary efficacy endpoint in patients with HER2-negative high-risk breast cancer. The results were published online in the ASCO 2013 Annual Meeting Proceedings, a supplement of the Journal of Clinical Oncology.
Fifteen patients diagnosed with non-metastatic HER2-negative breast cancer (ECOG status 0/1) were treated with EndoTAG-1 (22 mg/m2) in combination with paclitaxel (70 mg/m2) once weekly for 12 weeks as neoadjuvant therapy. Following EndoTAG-1 therapy, the patients received standard FEC (fluorouracil 500 mg/m2, epirubicin 100 mg/m2, and cyclophosphamide 500 mg/m2) chemotherapy every 3 weeks and, subsequently, surgery. The study’s primary endpoint was the percent reduction in tumor volume, as estimated by magnetic resonance imaging (MRI), at the end of administration of EndoTAG-1 plus paclitaxel compared with baseline.
Eleven (73%) of 15 patients showed a reduction in tumor volume of 80% or greater at the end of treatment with EndoTAG-1 plus paclitaxel. The median percent reduction in MRI-estimated tumor volume was 90% (P < 0.001) for 14 patients who underwent surgery; 99% for patients with a pathological complete response (pCR); and 84% for patients without a pCR.
The best results were observed in patients with triple-negative breast cancer (TNBC) (six of the 15 patients), all of whom showed reductions in tumor volume of 87% to 100%. Treatment in this group resulted in a pCR in five of the six patients.
During therapy, grade-3 hypersensitivity reactions to EndoTAG-1 were observed in four patients; two patients had a grade-3 increase in transaminases; and one patient had grade-4 neutropenia.
According to the drug’s developer (Medigene AG), the positively charged lipids in EndoTAG-1 imply that the drug interacts with newly developed, negatively charged endothelial cells, which are primarily required for the growth of tumor blood vessels. The paclitaxel component of EndoTAG-1 attacks the endothelial cells as they divide, thus targeting the blood supply to tumors without affecting the supply to healthy tissue. By doing this, EndoTAG-1 is expected to prevent the formation of new tumor blood vessels, thereby inhibiting tumor growth.
Source: Medigene AG; May 16, 2013.