SAN ANTONIO & NEU-ISENBURG, Germany & FRANKFURT, Germany--(BUSINESS WIRE)--The German Breast Group (GBG) said less may be more when it comes to the dose of innovative pharmaceuticals used to treat cancer. A follow-up to a Phase III trial presented at last year’s San Antonio Breast Cancer Symposium (SABCS) demonstrated a lower dose of nab-paclitaxel (ABRAXANE®) (125mg/m2/week) maintains efficacy and is less toxic than a higher dose (150mg/m2week) that was the starting point in the study. Both doses demonstrated improved efficacy compared to conventional paclitaxel, a taxane commonly used to treat many forms of cancer.
Nab-Paclitaxel encapsulates paclitaxel in nano-sized albumin (protein) shells. This leverages the natural transport properties of albumin, allowing for higher dose intensity and more drug at the tumor site. It can also be delivered directly into the blood stream without the use of solvents required to make standard paclitaxel water-soluble.
At the 2014 SABCS the GBG and the German Gynecological Oncology Working Group-Breast (AGO-B) demonstrated significant benefit for nab-paclitaxel for patients with early high-risk breast cancer when compared to conventional solvent-based paclitaxel. However, the optimal dose was in question. The updated results presented this year clearly demonstrate that the lower dose provides not only reduced side effects such as peripheral neuropathy, but better drug adherence.
Sibylle Loibl, chairman of the GBG said, “We noticed that patients on nab-paclitaxel did better than those on conventional solvent-based paclitaxel, however there was a high rate of patients discontinuing their treatment. So we reduced the weekly dose, from 150 mg to 125 mg, and this lower dose is what we recommend as the preferred schedule for nab-paclitaxel as neoadjuvant treatment for primary breast cancer.”
The presentation concludes the risk-benefit ratio was improved using nab-paclitaxel at the 125 mg dose with better drug adherence and relative total dose intensity, lower frequency of peripheral neuropathy and comparable pathological complete response (pCR). PCR after neoadjuvant treatment for breast cancer is a surrogate marker for long-term efficacy.
In all patients, not just the triple negative cases, pCR was 41% at 125 mg, 32% at 150 mg and 29% for conventional paclitaxel.
Peripheral neuropathy grade 3/4 dropped from 15% in the 150 mg cohort to just 8% at the 125 mg dose level. Neuropathy was lowest in the paclitaxel cohort (3%) but, as noted, conventional paclitaxel was not as effective.
ABOUT THE GERMAN BREAST GROUP
GBG is a large independent academic network of over 500 study centers in Germany with the world-wide largest experience in conducting neoadjuvant breast cancer trials. Since 1998, with joined forces from AGO-B, over 10.000 patients participated in the neoadjuvant “Gepardo” trial series. GBG has recruited at totality of over 35.000 patients to trials in breast cancer of all indications. For more information go to www.gbg.de. The GBG Research Institute received unrestricted grants and the provision of medication from Celgene and Roche for the conduct of the GeparSepto study. Nab-paclitaxel is approved in the US and Europe for patients with metastatic breast cancer.