Prolonged Response to Liposomal Irinotecan in a Patient with Stage IV Pancreatic/Bile Duct Cancer Previously Treated with FOLFIRINOX and Gemcitabine Plus Nab-Paclitaxel

At 9%, and 2% when diagnosed at advanced stage, the 5-year relative survival rate for pancreatic ductal adenocarcinoma (pdac) is the lowest of any cancer. The currently approved treatment options for metastatic pdac in the United States are folfirinox [irinotecan–fluorouracil (5fu)–leucovorin (lv)–oxaliplatin], gemcitabine–nab-paclitaxel, and liposomal irinotecan plus 5fu–lv. Liposomal irinotecan is a novel formulation of irinotecan encapsulated within a lipid bilayer, which favours local metabolic activation. The napoli-1 trial demonstrated the efficacy of liposomal irinotecan in combination with 5fu and lv for the treatment of advanced pdac after progression on gemcitabine-based chemotherapy. The 1-year survival in those patients was 25%; however, none had had irinotecan-refractory disease before treatment with liposomal irinotecan. Furthermore, the U.S. National Comprehensive Cancer Network guidelines recommend liposomal irinotecan plus 5fu–lv in patients who have received prior fluoropyrimidine-based therapy if no prior irinotecan therapy has been given. Here, we report a male patient with stage iv cancer of pancreas or bile duct (site unconfirmed) who experienced a prolonged (51 weeks) response to liposomal irinotecan plus 5fu–lv despite prior disease progression on irinotecan. Several factors have previously been associated with long-term survival in patients receiving liposomal irinotecan therapy: no prior irinotecan-based chemotherapy, high Karnofsky performance status score, age 65 years or less, serum carbohydrate antigen 19-9 less than 59 U/mL, neutrophil-to-lymphocyte ratio 5 or less, and absence of liver metastasis. The patient in the present report had none of those characteristics indicative of long-term survival, except his age at diagnosis—47 years.