Overall Survival Benefit with ONIVYDE® and Characteristics of Long Term Survivors in Metastatic Pancreatic Cancer

SUMMARY: The American Cancer Society estimates that for 2019, about 56,770 people will be diagnosed with Pancreatic cancer and about 45,750 people will die of the disease. Pancreatic cancer is the fourth most common cause of cancer-related deaths in the United States and Western Europe. Unfortunately, unlike other malignancies, very little progress has been made and outcome for patients with advanced Pancreatic cancer has been dismal, with a 5-year survival rate for metastatic Pancreatic cancer of approximately 2%. Pancreatic cancer has surpassed breast cancer as the third leading cause of cancer death in the United States and is on track to surpass colorectal cancer, to move to the second leading cause of cancer related deaths in the United States around 2020.

ONIVYDE® is a novel nanoliposomal encapsulation of Irinotecan, a topoisomerase 1 inhibitor. It is designed to optimize the delivery of Irinotecan, by extending the duration of circulation of the drug in the body and preferentially activating the drug within the tumor tissues, to achieve higher levels of the active cytotoxic drug metabolite, SN-38. This approach reduces the toxicity of Irinotecan to normal tissues while maintaining or increasing its anti-tumor efficacy.

NAPOLI-1 is an open-label, Phase III study in which 417 patients with Gemcitabine-refractory metastatic Pancreatic adenocarcinoma were randomly assigned in a 1:1:1 ratio to receive either ONIVYDE® monotherapy (N=151), ONIVYDE® plus 5-FluoroUracil (N=117) or 5-FU with Leucovorin (N=149). Sixty one percent (61%) of patients had cancer in the head of the Pancreas and 68% had liver metastases. Treatment consisted of ONIVYDE® 120 mg/m2 IV over 90 minutes every 3 weeks in Group A, ONIVYDE® 80 mg/m2 IV given over 90 minutes followed by 5-FU 2400 mg/m2 given over 46 hours and racemic Leucovorin 400 mg/m2 IV given over 30 minutes every 2 weeks in Group B and 5-FU 2000 mg/m2 IV given over 24 hours plus racemic Leucovorin 200 mg/m2 IV given over 30 minutes weekly for 4 weeks followed by 2 weeks of rest in Group C (Control group). Each of the two ONIVYDE® containing groups was compared with the 5FU/Leucovorin control group. Treatment groups were well balanced. The Primary study endpoint was Overall Survival and Secondary endpoints included Progression Free Survival (PFS) and Overall Response Rate (ORR). The authors in this publication reported the updated Overall Survival analysis from a longer follow up in the NAPOLI-1 trial, as well as baseline characteristics associated with long term survivors (survival of 1 year or more) in the NAPOLI-1 trial. The authors also provided the updated safety and tolerability data.

The combination of ONIVYDE®, 5-FU and Leucovorin maintained its median OS of 6.2 months compared with 4.2 months with 5-FU and Leucovorin alone, with an unstratified Hazard Ratio of 0.75 (P=0.04), and stratified Hazard Ratio of 0.63 (P=0.002). The estimated one-year survival rates were 26% in the ONIVYDE®, 5-FU and Leucovorin arm versus 16% in the 5-FU and Leucovorin combination control arm. Patient characteristics associated with long term survival in the ONIVYDE®, 5-FU and Leucovorin combination arm included Karnofsky Performance Status of 90 or more, age 65 years or less, lower serum CA19-9 levels, Neutrophil-to-Lymphocyte ratio of 5 or less and no liver metastases. There was again no OS advantage with ONIVYDE® monotherapy, when compared with 5-FU and Leucovorin (4.9 versus 4.2 months). The median PFS was 3.1 months in patients receiving ONIVYDE®, 5-FU and Leucovorin and 1.5 months in those receiving 5-FU and Leucovorin combination alone (HR=0.57; P < 0.0001), and was 2.7 months for ONIVYDE® monotherapy compared with 1.6 months for 5-FU and Leucovorin combination control group. The ORR was significantly higher with ONIVYDE®, 5-FU and Leucovorin combination (17%) compared with 1% for the 5-FU and Leucovorin combination (P < 0.0001) and the Disease Control Rate was also higher with ONIVYDE®, 5-FU and Leucovorin combination (52%) versus 24% for the 5-FU and Leucovorin combination control group. No new safety concerns were detected in the current updated analysis.

The authors concluded that for patients with metastatic Pancreatic adenocarcinoma, a combination of ONIVYDE®, 5-FU and Leucovorin improves Overall Survival, Progression Free Survival, CA19-9 response and Disease Control Rate, with an acceptable safety profile, and represents a new standard of care following Gemcitabine-based therapy. This updated analysis also identified prognostic markers associated with longer survival. NAPOLI-1 phase 3 study of liposomal irinotecan in metastatic pancreatic cancer: Final overall survival analysis and characteristics of long-term survivors. Wang-Gillam A, Hubner RA, Siveke JT, et al. European Journal of Cancer 2019;108:78-87