The immune-boosting GOLFIG regimen increased progression-free survival in colorectal cancer so effectively that the study initiated to evaluate the treatment was prematurely terminated.

Patients with advanced colorectal cancer usually undergo combination therapy with fluorouracil or the derivative product, capecitabine, with or without levofolinic acid, with irinotecan (FOLFIRI) or oxaliplatin (FOLFOX) given alone or with the monoclonal antibodies bevacizumab, cetuximab, or panitumumab.

Although these combinations have been successful in inducing tumor regression, slowing disease progression, and increasing overall survival, “The average progression-free survival and overall survival are still no more than 8 to 10 months and 20 to 22 months, respectively,” noted Pierpaolo Correale, MD, PhD, in a statement describing his Phase III study examining a new regimen: gemcitabine plus FOLFOX followed by granulocyte-macrophage colony stimulating factor and low-dose aldesleukine (GOLFIG).

Correale, an oncologist at the Siena University School of Medicine in Siena, Italy, and colleagues randomized 130 patients to receive FOLFOX or GOLFIG for up to 12 cycles. The participants then received maintenance treatment until their disease progressed. 

Although the study was designed to study enrollees in both arms until death, the significantly better results seen with the GOLFIG regimen ended the study early: By the time Correale presented his group’s results at the annual meeting of the American Association for Cancer Research (AACR), held April 2-6, 2011, in Orlando, Florida, GOLFIG patients had a progression-free survival of 16.5 months, compared with 7.5 months for the FOLFOX subjects.

“Based on our experience and results to date, we believe that the GOLFIG regimen is superior to FOLFOX chemotherapy in terms of efficacy and comparable in terms of toxicity and cost,” commented Correale in the statement. “We were very surprised to find such a significant difference in terms of overall survival with this low number of patients.”

He also noted that future research should focus on comparing GOLFIG with regimens containing monoclonal antibodies, which were not routinely used when his group began the study in 2005.