Efficacy of Gembrax Followed by Folfirinox Versus Folfirinox Alone in First Metastatic Line Pancreatic Cancer Patients

Pancreatic cancer is the third leading cause of cancer death in 2016, surpassing breast cancer. It is estimated that by 2030 pancreatic cancer will become the second leading cause of cancer death after lung cancer.

Its prognosis is very poor, with a 5-year overall survival rate (OS) at all stages of 5.5%.

In France, its incidence doubled in men and tripled in women between 1982 and 2012. The World Standardized Rate (MSR) for men and women respectively was 4.9% and 2% in 1980 and 10.2% and 6.9% in 2012. This means an annual rate of change of 2.3 for men to 3.9 for women.

Its diagnosis is often late, carried out in 50% of cases at stage 4, with limited treatment options, explaining its low survival rate at 5 years.

Until 2011, gemcitabine remained the only validated standard with a median survival of 6 months.

Many combinations with gemcitabine have been evaluated but have shown no significant survival advantage over Gemzar alone.

The most promising results reported to date remain the combination of oxaliplatin, irinotecan and 5 fluoro-uracil (FOLFIRINOX), which became the standard metastatic first-line treatment thanks to the results of the phase III study, ACCORD11, randomizing gemcitabine to FFX with for the first time, a significant gain in median survival, progression-free survival and response rate in favor of the experimental arm of 6.8 months vs. 11.1 months respectively ([HR 0.57, 95 % IC, 0.45-0.7 3];p<0.001), 3.3vs6.4 ([HR 0.47, 95 % IC, 0.37- 0.59];p<0.001) et de 9.4 % vs 31.6 % ; p>0.001.

In 2013, the combination gemcitabine nab-paclitaxel (GEMBRAX) showed, in a randomized phase III study, compared to gemcitabine, a significant gain in terms, median survival, survival without progression and response rate in favor of the experimental arm, respectively for gemcitabine vs GEMBRAX, 6.7 months vs 8.5 months ([HR 0.72, 95 % IC, 0.62-0.83];p<0.001) ; 3.7vs 5.5. ([HR 0.69, 95 % IC, 0.58- 0.82];p<0.001) et de 7 % vs 23% ; p>0.001.

FOLFIRINOX and GEMBRAX, two chemotherapy protocols which have shown their effectiveness in the 1st metastatic line with a gain in terms of response rate, progression-free survival and median survival but with increased grade 3/4 toxicities, compared to treatment with gemcitabine.

For FOLFIRINOX: a neutropenia rate of 45.7% vs 21% including 5.4% of febrile neutropenia vs 1.2, a rate of diarrhea of 12.7% vs 1.8% and peripheral neuropathies of 9% vs 0

For GEMBRAX neutropenia 38% VS 27% including 3% febrile neutropenia VS 1%, 6% diarrhea vs 1% and peripheral neuropathy 17% vs 1%:

Given the high toxicities, only patients with favorable performance status are eligible to receive these regimens.

The sponsor therefore considered a new concept of sequential GABRINOX treatment combining GEMBRAX followed by FOLFIRINOX, which should make it possible, by reducing toxicities, to increase the response rate and at the same time progression-free survival and median survival.

The sponsor performed a phase 1/2 study evaluating this GABRINOX protocol with the main objective of determining the maximum tolerated dose and increasing the response rate. Phase 2 is encouraging with a disease control rate and an objective response rate of 84.2% and 64.9% respectively, progression-free survival at 10.5 months and overall survival at 15.1 months as well as a more favorable safety profile compared to non-sequential treatments (less neutropenia 34.5%, febrile neutropenia 3.5% and neurotoxicity 5.2%).

These encouraging results led the investigator to propose a phase 2 study comparing the standard first-line treatment regimen FOLFIRINOX with the sequential regimen GABRINOX with the main objective of comparing efficacy in terms of objective response rate.