Maintenance therapy and treatment holiday in patients with unresectable/locally advanced/metastatic pancreatic cancer who did not progress after at least 2 months of first-line chemotherapy.

Abstract

e16372 Background: Although the overall prognosis of metastatic pancreatic cancer remains poor, according to SEER database there has been a gradual improvement in 5-year survival rate over the past decade plus, from 5% in 2000 to 13% as of 2016. This gradual yet significant improvement in long-term survival is in part attributable to improved efficacy of first line systemic therapy in the metastatic setting. With continued advances in systemic therapy, there will likely be an increasing number of long-term survivors who will be eligible for maintenance therapy or treatment holiday. Currently, there is limited data regarding efficacy and safety of maintenance therapy and treatment holiday in pancreatic cancer compared to other solid malignancies. Therefore, there is a growing area of unmet need in devising an optimal, safe treatment strategy for patients with advanced pancreatic cancer who had an initial favorable response to first line therapy. Methods: This study is a retrospective review of 274 patients with unresectable or metastatic pancreatic cancer (including de novo metastatic disease and progression from localized disease to metastatic disease) who did not undergo curative resection or had recurrence after resection. Patients received systemic therapy in the advanced setting for at least 2 months within Tufts Medicine network from 1/2014 to 5/2025. The data collected included demographic data (age, sex, BMI, ECOG), stage at diagnosis, number and location of metastatic sites, chemotherapy regimens, and disease outcomes (PFS1, OS, PFS2, DDC, adverse effects) which were compared across 3 different treatment strategy groups after at least 2 months of 1 st line chemo (group 1: continuation of 1 st line; group 2: maintenance; group 3: treatment holiday). Results: A total of 59 patients met the inclusion criteria (group 1: n = 36, group 2: n = 17, group 3: n = 6). Median age was 65 and there were 64% males. Median duration of 1 st line therapy was 5.3, 5.1, and 3 months, respectively. Group 2 led to statistically significant improvement in OS (18 mo vs 13.1 mo, HR 0.31), PFS1 (12.2 mo vs 6.5 mo, HR 0.16), and DDC (13.9 mo vs 9.5 mo, HR 0.20) compared to group 1, adjusted for age, sex, and BMI, but there was no statistically significant difference in PFS2. There was no statistically significant difference between group 1 and group 3 in terms of survival outcomes. Safety data showed diarrhea and fatigue were the most common adverse events during maintenance therapy, and all but 1 were grade 1-2. Conclusions: Maintenance therapy led to statistically significant improvement in PFS1 and OS compared to continuation of 1 st line therapy after at least 2 months, while having a favorable safety profile. Limitations include small sample size especially in treatment holiday group. Maintenance therapy should be studied in prospective trials.