Abstract 341P
Background
Results of the phase II/III JCOG1611 trial in metastatic pancreatic cancer showed first-line gemcitabine + nab-paclitaxel (GnP) is more appropriate than modified FOLFIRINOX or S-IROX as standard treatment. However, after progression or intolerance on gemcitabine-based regimens followed by second-line nanoliposomal-irinotecan + 5-FU/leucovorin (nal-IRI + 5FU/LV), third-line treatment options remain unspecified. In clinical practice, S-1 or FOLFOX are commonly used in Japan as a third-line treatment for patients with preserved performance status (PS), but their comparative effectiveness is unknown.
Methods
Electronic medical record data were retrospectively analyzed from June 2020 to May 2023 for patients who received nal-IRI + 5FU/LV as second-line treatment after first-line GnP at the National Cancer Center Central Hospital (Tokyo, Japan).
Results
One hundred patients were included, and 41 patients received S-1 or FOLFOX as third-line therapy. Among these patients, 19 cases were treated with S-1 and 22 cases with FOLFOX; the median age for S-1/FOLFOX was 74 (range: 56–85)/76 (46–81) years; females were 8/14; PS 0 was 6/11, and PS 1 was 13/11. The histology of adenocarcinoma was 18/20. Progression-free survival (PFS) for S-1 and FOLFOX was 2.8/2.2 months (hazard ratio [HR] 1.2, 95% confidence interval [CI] 0.61–2.4, p = 0.59). Overall survival (OS) was 4.4/4.8 months (HR 1.2, 95%CI 0.53–2.7, p = 0.67). The overall response rate was 0/0%, and the disease control rate was 36.8/27.3%. Subgroup analysis showed no significant differences in factors associated with PFS and OS between these two regimens. The most common grade 3 or higher adverse events were anemia (4/1) and ALT increase (1/3). Adverse events were within known limits, and there was no treatment-related death.
Conclusions
In patients with metastatic pancreatic cancer treated with GnP followed by nal-IRI+5FU/LV, third-line treatment with S-1 or FOLFOX was tolerable. However, further therapeutic development is warranted since these regimens had limited therapeutic benefits.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.