Priority Review Granted for Nab-Paclitaxel in Metastatic Pancreatic Cancer

Daniel D. Von Hoff, MD

The FDA has granted priority review to nab-paclitaxel (Abraxane) in combination with gemcitabine for the first-line treatment of patients with metastatic pancreatic cancer, as part of its supplemental new drug application.

An action date for nab-paclitaxel in pancreatic cancer is set for September 21, 2013, in accordance with the Prescription Drug User Fee Act.

The government agency grants priority review to drugs that have the potential of offering a major advancement in treatment when no existing adequate therapy exists. By granting priority review, the review period is reduced from the standard 10 months to six months. In the case of pancreatic cancer, the FDA has not approved any drugs since erlotinib was approved for the treatment of locally advanced, unresectable or metastatic disease in 2005.

The FDA will review nab-paclitaxel based on the results of the phase III Metastatic Pancreatic Adenocarcinoma Clinical Trial (MPACT), which were presented at the 10th Annual Gastrointestinal Cancers Symposium in January. In that trial, 861 patients with stage IV pancreatic cancer who received no prior treatments for metastatic disease were randomized to receive nab-paclitaxel at 125 mg/m² followed by gemcitabine 1000 mg/m² (n = 431) or gemcitabine alone (n = 430). Patients received treatment until their disease progressed.

Patients who received the nab-paclitaxel combination had a median overall survival of 8.5 months compared with 6.7 months in patients who received gemcitabine alone (hazard ratio [HR] = 0.72; P =.000015). The one-year survival rate was 35% in the nab-paclitaxel arm compared with 22% in the gemcitabine arm (P = .0002). The median progression-free survival was also higher in the nab-paclitaxel arm at 5.5 months compared with 3.7 months in the gemcitabine alone arm (HR=0.69; P = .000024).

The overall response rate, as assessed by independent review, also favored nab-paclitaxel, as patients in that arm of the study had a response rate of 23% compared with 7% in the gemcitabine alone arm. Time to treatment failure was longer in the combination arm at 5.1 months compared with 3.6 months in the control arm (HR = 0.70; P = .0001).

“The past few decades have brought us very few treatment advances for patients with advanced pancreatic cancer, which is both deadly and incredibly difficult to treat with success,” Daniel D. Von Hoff, MD, the lead principal investigator of the MPACT study said in a statement when the data was originally presented at the conference. “The fact that Abraxane plus gemcitabine demonstrated an overall survival benefit, and also did so at one and two years, is a significant step forward in offering potential new hope for our patients.” Von Hoff is the Chief Scientific Officer for Scottsdale Healthcare’s Virginia G. Piper Cancer Center Clinical Trials and Physician-In-Chief for the Translational Genomics Research Institute (TGen).

According to Celgene International Sàrl, a subsidiary of Celgene Corporation, a phase III, international, multicenter, randomized controlled trial evaluating the activity of nab-paclitaxel plus gemcitabine as an adjuvant treatment for pancreatic cancer is currently under development.

In 2012, nab-paclitaxel in combination with carboplatin received FDA approval for the first-line treatment of patients with locally advanced or metastatic non-small cell lung cancer who cannot receive surgery or radiation therapy. The agent was first approved in 2005 for the treatment of metastatic breast cancer after failure of combination chemotherapy.

Von Hoff DD, Ervin TJ, Arena FP, et al. Randomized phase III study of weekly nab-paclitaxel plus gemcitabine versus gemcitabine alone in patients with metastatic adenocarcinoma of the pancreas (MPACT). Presented at the 10th Annual Gastrointestinal Cancers Symposium; January 24-26, 2013; San Francisco, CA. Abstract LBA 148.