Drug Combo Effective against Pancreatic Cancer

Until 2011, gemcitabine (Gemzar; Eli Lilly) was the only treatment choice for patients with late-stage pancreatic cancer. “This was a disease for which there was basically nothing—zero,” says Robert Mayer, MD, vice president for academic affairs and a gastrointestinal cancer specialist at Dana-Farber Cancer Institute in Boston, MA.

That year, results from a large clinical trial showed that patients taking FOLFIRINOX, an intense regimen of 4 chemotherapeutics already in use, lived longer than those taking just gemcitabine (11.1 months vs. 6.8 months). “FOLFIRINOX changed the treatment landscape,” notes Mayer.

That landscape might soon be altered again, based on a phase III trial of nab-paclitaxel (Abraxane; Celgene) plus gemcitabine, reported at the 2013 Gastrointestinal Cancers Symposium in San Francisco, CA, in January by Daniel Von Hoff, MD, physician-in-chief of Translational Genomics Research Institute in Phoenix, AZ.

The international, multisite MPACT (Metastatic Pancreatic Adenocarcinoma Clinical Trial) study compared 431 patients with metastatic pancreatic cancer who took nab-paclitaxel and gemcitabine with 430 who took gemcitabine alone. The patients on the nab-paclitaxel–gemcitabine combination fared better in multiple measures than those taking gemcitabine alone, including median overall survival (8.5 months vs. 6.7 months), survival at 1 year (35% vs. 22%), and survival at 2 years (9% vs. 4%). On the downside, the nab-paclitaxel–gemcitabine combination was more likely to produce serious side effects, including neutropenia, fatigue, and neuropathy.

Nab-paclitaxel, an albumin-bound form of paclitaxel, is approved by the U.S. Food and Drug Administration for the treatment of metastatic breast cancer and, in combination with carboplatin, non–small cell lung cancer. Based on the MPACT results, Celgene is expected to seek approval for a pancreatic cancer indication this year.

Without a direct side-by-side comparison, it is impossible to be certain which is more effective, nab-paclitaxel plus gemcitabine or FOLFIRINOX, although the results from the 2 separate studies suggest that FOLFIRINOX might have an edge.

Mayer, who was not involved in the MPACT study, says he has treated about a dozen patients with FOLFIRINOX, one of whom has lived for 2 years. Even so, he cautions that the drug regimen is “not for the faint of heart.” Side effects of the 4 drugs, given as successive intravenous infusions, include neutropenia, anemia, fatigue, vomiting, and diarrhea. The nab-paclitaxel–gemcitabine combination may have fewer harsh side effects.

“The bottom line for me, as a clinical investigator, is that we now have some real choices,” says Mayer.