Adjusted Regimen of Abraxane and Gemzar Less Toxic in Pancreatic Cancer

Changing the administration schedule for Gemzar (gemcitabine) plus Abraxane (nab-paclitaxel) from weekly to every other week significantly reduced side effects without impacting efficacy as a frontline treatment for patients with metastatic pancreatic cancer, according to a retrospective study presented at the 2015 GI Cancers Symposium.

The less-intense treatment schedule demonstrated a median overall survival (OS) of 11.1 months and a median progression-free survival (PFS) of 4.8 months. Moreover, the change in dosing reduced patient medical costs by $5,500 per month.

“Shifting this treatment to every other week gives the immune system time to recover between chemotherapy sessions and results in less overall toxicity. It also means fewer visits to the infusion center to receive chemotherapy,” study author Tanios Bekaii-Saab, gastrointestinal oncology section chief at The Ohio State University Comprehensive Cancer Center (OSUCCC) — James, said in a statement. “This less-intense, every-other-week treatment approach seems to be effective in treating our patients with metastatic pancreatic cancer while significantly reducing side effects that impact quality of life.”

The Food and Drug Administration approved the combination regimen of Gemzar and Abraxane for the treatment of patients with metastatic pancreatic cancer in September 2013. The approval was based on results from the MPACT trial, which showed that weekly Abraxane combined with Gemzar significantly improved both OS and PFS. In the study, the median OS was 8.5 months with Alimta plus Gemzar compared with 6.7 months with Gemzar alone. The median PFS was 5.5 months with the combination compared with 3.7 months with Gemzar alone.

“The combination of gemcitabine and nab-paclitaxel in pancreatic cancer is one of the most recent advances in pancreatic cancer treatment and has been shown to improve survival when compared to gemcitabine alone,” first author Kavya Krishna, a hematology oncology fellow at The OSUCCC — James, said in a statement. “But this improved survival comes with increased toxic side effects that can affect quality of life. We sought an alternative regimen that would prolong treatment effectiveness and reduce side effects.”

The singe-institution retrospective study examining the new schedule was based on information in a prospectively maintained database. The analysis looked at 69 patients with pancreatic cancer who received the combination regimen on days 1 and 15 of a 28-day treatment cycle. Of these patients, 49 had previously untreated metastatic pancreatic cancer and the remaining 20 patients had progressed on other treatments or had locally advanced or borderline resectable disease. The median age of patients in the study was 65 years.

Compared with the MPACT study, the rate of adverse events was considerably less. The incidence of neurological toxicity was less than 2 percent with the adjusted regimen compared with 17 percent in the MPACT study. Severe low blood cell counts were seen in 10 percent of patients with the every other week dose versus 38 percent with the weekly schedule. Growth factor injections were required in 8 percent of patients in the database analysis compared with 26 percent in the MPACT study. Grade 3 or greater neutropenia, anemia, thrombocytopenia, fatigue and diarrhea were markedly less with the less-intense regimen. Additionally, the rate of neuropathy was 1.6 percent with the every other week dose versus 7 percent with weekly Abraxane plus Gemzar.

These new findings could significantly improve the quality of life for pancreatic cancer patients, said Krishna. “Pancreatic cancer is an especially difficult diagnosis, so weighing the survival benefit of available treatments against how treatment side effects will impact a patient’s remaining life is a critically important part of the treatment planning process.”