Washington – A combination of nab-paclitaxel (AbraxaneR for Injectable Suspension) and gemcitabine improves survival when used as first-line treatment in patients with advanced pancreatic cancer, researchers announced at the 101st Annual Meeting of the American Association for Cancer Research (AACR).

Daniel Von Hoff, MD, Physician-in-Chief and Senior Investigator at the Translational Genomics Research Institute in Phoenix, Arizona, reported results in 67 patients treated with a combination of nab-paclitaxel and gemcitabine as part of a phase I/II open-label study.

In the phase I dose-escalation portion of the study, nab-paclitaxel (100, 125, 150 mg/m2) in combination with gemcitabine 1000 mg/m2 was administered weekly for three weeks with one week of rest. The 125 mg/m2 dose was identified as the maximum tolerated dose.

Of 44 patients who were treated with nab-paclitaxel at the recommended dose of 125 mg/m2 with gemcitabine, 1000 mg/m2, the median overall length of survival was 12.2 months – or twice the survival length that has been reported in patients receiving solo gemcitabine.

Of patients treated with the combination therapy, the overall response rate was 50% and the disease control rate was 68%. A disease control rate was defined as a complete response, partial response, and stable disease for 16 weeks or longer according to Response Evaluation Criteria in Solid Tumors (RECIST) criteria.

Also, all patients in the nab-paclitaxel arm who were tested for the serum carbohydrate antigen CA19-9 showed a decrease in tumor marker levels that exceeded 20%. A CA19-9 decrease of this magnitude has been shown to correlate with improved overall survival.

Of 54 patients screened for CA19-9, 69% had a decrease in biomarker levels exceeding 70%. A CA19-9 decrease of this magnitude correlates with a median overall survival of 15.6% in this patient subgroup.

Overall, three patients in the overall study population of 67 patients had a complete response.

Nab-paclitaxel is thought to work by exploiting the albumin-binding protein receptor Gp-60 in the blood vessel wall, thereby opening a portal to the tumor micro-environment, a spokesperson for Abraxis BioScience in Los Angeles, which developed nab-paclitaxel, said in a news release. This portal, in turn, sets the stage for enhanced delivery of cytotoxic agents when given in combination with nab-paclitaxel.

In 2010, more than 42,000 are expected to be diagnosed with pancreatic cancer in the U.S. this year, and more than 35,000 people are expected to die of the disease.

Abraxis BioScience sponsored the study.

Written by Jill Stein
Jill Stein is a Paris-based freelance medical writer.