On September 6th the U.S Food and Drug Administration (FDA) – per its commendable fast track expedited review program for “orphan” diseases (which now includes pancreatic cancer) has approved nab-paclitaxel (trade name: Abraxane) for use in in combination with gemcitabine for metastatic pancreatic cancer. The previous drug agent officially approved by the FDA for pancreatic cancer (occurred on November 2, 2005) was the targeted agent erlotinib (trade name: Tarceva) in combination with gemcitabine.
This rather remarkable rapid FDA approval stems from the outcomes of the Metastatic Pancreatic Adenocarcinoma Clinical Trial (MPAC study) presented this past January in San Francisco at the American Society of Clinical Oncology’s 2013 Gastrointestinal Cancers Symposium by Daniel Von Hoff, MD, the physician-in-chief and director of Translational Research at the Translational Genomics Research Institute.
Paclitaxel is one of the taxane family of drug agents, and available in the U.S. as Taxol, which is approved for use in the treatment of several cancers. Nab-paclitaxel has been developed by the Calgene biotech company and is formed by adding the protein molecule albumin to the drug complex. Abraxane has previously been approved by the FDA for use in metastatic breast cancer and non-small cell lung cancer.
One interesting fact is that Dr. Von Hoff also led the research team that developed the work resulting in the 1996 FDA approval of gemcitabine for the treatment of pancreatic cancer.
MPAC was a multi-country, multi-center (151 community and academic centers) Phase III clinical trial involving 861 patients with previously untreated advanced pancreatic cancer who were randomly assigned to one of two arms: to receive either standard gemcitabine treatment OR to receive 125/m2 of nab-paclitaxel followed by standard gemcitabine treatment.
The MPAC patient group that was given the Abraxane/gemcitabine combined therapy demonstrated a 59% increase in the 12-month median survival rate above the group that had been treated with only gemcitabine. The Abraxane combination arm showed about a two month increase in overall survival advantage above the gemcitabine single treatment arm (8.5 months versus 6.7 months). Also, the 12-month survival rose from 22% to 35% in the group that was given the combination regimen at an impressive P=0.0002. The 2-year survival was still poor but increased with the combination to 9% from 4% over single therapy.
It would seem that the FOLFIRINOX regimen presented in 2011 and now this Abraxane/gemcitabine regimen appear to represent modest but definite advantage in the treatment of metastatic adenocarcinoma of the pancreas. Further research will undoubtedly further illuminate the nature and extent of these particular advantages – and present indications for these and single therapy (gemcitabine) as first-line treatment standard of care.
Dale O’Brien, MD