Phase 1 trial of HR070803 (an Irinotecan liposome) in combination with 5-fluorouracil, leucovorin, and oxaliplatin for untreated advanced or metastatic pancreatic ductal adenocarcinoma.

Background: This study assessed the safety, preliminary antitumor activity, and pharmacokinetics of HR070803 (a novel liposomal irinotecan) in combination with 5-FU/LV and oxaliplatin for treatment-naive patients with unresectable locally advanced or metastatic pancreatic ductal adenocarcinoma (PDAC).

Methods: This multicenter, open-label, single-arm, dose-escalation phase 1 study recruited treatment-naive patients aged 18-70 years with unresectable locally advanced or metastatic PDAC. Treatment doses were escalated from 40/60 (HR070803 40 mg/m plus 5-FU/LV and oxaliplatin 60 mg/m) to 60/60 and 60/85. The primary endpoints were maximum tolerated dose (MTD) and the recommended phase 2 dose (RP2D). Secondary endpoints included safety, preliminary antitumor activity, and pharmacokinetics.

Results: A total of 41 patients were enrolled, including 6, 17, and 18 patients in the 40/60, 60/60, and 60/85 group, respectively. Only one patient in the 60/60 group experienced dose-limiting toxicities of grade 3 increased alanine aminotransferase and grade 3 increased aspartate aminotransferase, and the MTD was not reached. Adverse events of grade ≥ 3 were reported in 31 (75.6%) patients, with the most common being decreased neutrophil count and increased gamma-glutamyltransferase. No treatment discontinuation occurred owing to adverse events, and there were no treatment-related deaths. The overall response (complete or partial response) rate was 29.3% in the total population. Pharmacokinetic results demonstrated prolonged circulation and slow release of free irinotecan.

Conclusions: HR070803 plus 5-FU/LV and oxaliplatin demonstrated an acceptable toxicity, good antitumor activity, and favorable pharmacokinetic profile as a first-line treatment for patients with unresectable locally advanced or metastatic PDAC. Based on the comprehensive data obtained during the dose escalation and dose expansion stages, HR070803 60 mg/m plus 5-FU/LV and oxaliplatin 85 mg/m was chosen as the RP2D.

Trial Registration: Clinical trials.gov NCT04796948; registered March 15, 2021.