Impact of treatment patterns on clinical outcomes in patients of advanced pancreatic cancer treated with chemotherapy: A large-scale data analysis from real world practice.

e16367 Background: Fewer treatment choices are available for advanced pancreatic cancer (APC). Nab-paclitaxel is one the most important drugs and has been reimbursed from 2018 at Taiwan. Nab-paclitaxel and gemcitabine (PG)-contained treatment protocols as the first line treatment for APC vary between hospitals. This study aimed to evaluate treatment patterns and clinical outcomes in patients with APC initiating with PG in real-world settings at different hospitals. Methods: In this observational retrospective cohort study, data of 206 APC patients from 3 hospitals who initiated the first line therapy with PG-based regimen between January 1, 2018 and May 31, 2024 were collected and analyzed. The study assessed prescription schedule, overall response rate (ORR), progression free survival (PFS), time to next treatment or death (TTNTD), overall survival (OS) and adverse events (AE) of interest. Results: ORR was 26.3%, included 1.5% complete rate, median PFS was 5.5 (95% CI 4.7-6.3) mos and median OS was 9.7 (95% CI 8.5-10.9) mos. The main reason of discontinuation was disease progression (62.9%), there were still 108 cases could receive 2 nd line treatment, most of them received liposomal irinotecan (77.8%). Deescalating maintenance therapy with gemcitabine or S-1 after APC got control were prescribed for some cases. S-1 was the most common drug as a maintenance therapy. Patients who received maintenance therapy could extent OS to14.8(95% CI 7.9-21.7) mos. If PG regimen combined with S-1, the median OS could also be extended to 15.3(95% CI 4.4-26.2) mos, compared to 8.8(95% CI 7.6-10.0) mos without S-1. Median PFS and OS varied within 3 hospitals, the median TTNTD of PG-based regimen were 7.8 mos, 4.9 mons, and 5.5 mos separately. Median OS were 12.7 mos, 9.6 mons and 6.9 mos separately. Most common Gr 3, or 4 AEs were neutropenia (18.9%), peripheral neuropathy (6.8%), nausea (6.3%) and dermatitis (4.9%). Conclusions: APC is still an aggressive disease with dismal outcome. PG-based combination therapy can improve therapeutic effects. Add-on S-1 could further improve PFS and OS. Deescalating continuous maintenance therapy also led to better OS and quality of life for patients. Our result implies ingeniously using available drugs could get better PFS and OS without increasing AE for APC patients.