449 Background: Recently, gemcitabine (GEM) plus nab-paclitaxel (nab-PTX) has been frequently used as a first-line chemotherapy regimen for the treatment of metastatic pancreatic cancer (mPC) in Japan. Nanoliposomal irinotecan combined with 5-fluorouracil and leucovorin (MM-398 plus 5FU/LV) has not yet been approved in Japan. Under these circumstances, a modified FOLFIRINOX (mFFX) regimen or S-1 is commonly used as a second-line chemotherapy regimen for patients with mPC after GEM plus nab-PTX has failed. Methods: Between December 2014 and March 2016, 45 patients with mPC received second-line chemotherapy after the failure of GEM plus nab-PTX (standard dose regimen) at the National Cancer Center Hospital East. Twenty-two patients received mFFX (irinotecan, 150 mg/m2; bolus of 5FU was eliminated), 19 received S-1 (80 mg/m2/d; d1-28, q6w or d1-14, q3w), and 4 received other chemotherapy regimens. The clinical records of the patients were reviewed retrospectively. Results: At baseline, S-1 group had a more severe disease status than the mFFX group (performance status of 0: 21% vs. 68%, P = 0.003; median CA19-9 level: 1832 vs. 577 U/mL, P = 0.30). No significant difference in the response rate (S-1, 5.3% vs. mFFX, 9.1%, P = 0.56) or the disease control rate (S-1, 42% vs. mFFX, 36%, P = 0.71) was seen between the two groups. The progression free survival (PFS) (median: S-1 vs. mFFX: 2.7 vs. 2.4 months (m), P = 0.77), the overall survival (OS) from the second-line treatment (median: 6.1 vs. 6.4m, P = 0.87) and the OS from the first-line treatment (median: 10.9 vs. 12.4m, P = 0.77) were not significantly different between the two groups. These results were similar to those observed for MM-398 plus 5FU/LV (PFS, 3.1m; OS, 6.1m) in a pivotal Phase III study (NAPOLI-1). The incidences of peripheral neuropathy (5.3% vs. 32%, P = 0.04), fatigue (11% vs. 50%, P = 0.007), and neutropenia (11% vs. 64%, P = 0.001) were significantly lower in the S-1 group. Conclusions: S-1 was less toxic than mFFX and exerted a similar anti-tumor effect in the present study. S-1 could be a treatment option for patients with mPC refractory to GEM plus nab-PTX.
FOLFOX as second-line chemotherapy in patients with pretreated metastatic pancreatic cancer from the FIRGEM study
