Anti-PD-1 therapy combined with chemotherapy in patients with advanced pancreas cancer in a real-world clinical setting.

Abstract

e14103 Background: Pancreatic cancer (PC) is a highly lethal disease and characterized by a strong resistance to current radiotherapy and chemotherapy. As PC has the presence of a microenvironment filled with immunosuppressive mediators and a dense stroma which involved in immune system control, the immune system has been hypothesized to play an important role in PC. However, there was no response in patients who received immune checkpoint inhibitors (ICIs) monotherapy. Though small sample studies revealed that ICIs combined with chemotherapy is effective, a head-to-head comparison of ICIs plus chemotherapy and chemotherapy is limited. Methods: Advanced PC patients treated with chemotherapy alone or plus ICIs were retrospectively screened for eligibility. Patients previously treated with any agent targeting T-cell co-stimulation or checkpoint pathways was excluded. The primary outcome was overall survival (OS). Secondary outcomes were progression-free survival (PFS), overall response rate (ORR) and safety. Results: In total, 58 patients were included (combination, n = 22; chemotherapy, n = 36). Combination group presented significantly longer OS than chemotherapy group (median, 18.1 vs 6.1 months, HR 0.46 [0.23-0.90], P = 0.021). Median PFS was 3.2 months in the combination group and 2.0 months in the chemotherapy group (HR 0.57 [0.32-0.99], P = 0.041). The ORR was similar between the combination group and the chemotherapy group with no significant difference (18.2% vs 19.4%, P = 0.906). And all the patients, who reached partial response, accepted a two-chemotherapic-drugs regimen regardless of combinating with ICIs. Adverse events of grade 3 or higher occurred in 31.8% of the patients in the combination group and in 16.9% of those in the chemotherapy group. Though the incidence rate of serious treatment-related adverse events (TRAEs) was higher in the combination group than the chemotherapy group, no statistical significance existed (P = 0.183). Conclusions: Combination of ICIs plus chemotherapy is effective and tolerable for advanced PC. Accepting ICIs combined with a two-drug chemotherapy regimen might be the better choice.