A phase 2 study of liposomal irinotecan with 5-fluorouracil and leucovorin in squamous cell carcinoma of head and neck or esophagus after prior platinum-based chemotherapy or chemoradiotherapy

6025 Background: Liposomal irinotecan (nal-IRI) + 5-FU/LV has been approved and used in treating patients with metastatic pancreatic cancer after gemcitabine-based therapy through the NAPOLI-1 study result. This phase 2 trial evaluated the activity of NAPOLI-1 regimen in patients with squamous cell carcinoma (SCC) of head and neck (H&N) or esophagus that progressed on or recur after platinum-based chemotherapy or concurrent chemoradiotherapy. Methods: Patients with histologically confirmed SCC of H&N or esophagus whose disease progressed while on or progressed/recurred within 6 months after platinum-based chemotherapy or chemoradiotherapy, and unsuitable for further surgical or radiation intervention were eligible. Prior anti-EGFR or anti-PD1/anti-PDL1 treatment was allowed. The regimen consisted of nal-IRI 70 mg/m2 (irinotecan free base) followed by LV 400 mg/m2 and 5-FU 2400 mg/m2, every 2 weeks. A Simon’s 2-stage design was used with planned 30 evaluable patients in the first stage and 52 evaluable patients in total. The primary endpoint is objective tumor response. Results: From December 2018 to April 2020, 59 subjects were enrolled, including 16 with esophagus cancer and 43 with H&N cancer. Thirty-seven (63%) patients had metastatic disease at enrollment. The mean of treatment cycles were 5 (range, 1-21). Among the total 59 enrolled subjects, 53 subjects (14 esophagus cancer, 39 H&N cancer) were evaluable for objective tumor response. The disease control rate in esophagus cancer was 50% (7 SD, intent-to-treat (ITT) population 43.8%). For H&N patients, 1 CR, 4 PR, and 23 SD resulted in the response rate 12.8% (11.6% in ITT population) and disease control rate 72% (65% in ITT population). The median progression free survival (N = 59) was 2.5 months (esophagus/H&N: 1.5/2.7 months) and the median overall survival was 5.9 months (esophagus/H&N: 4.2/7.3 months). Seventy-eight percent of patients had ≥grade 3 treatment-related adverse events. The most frequent ≥grade 3 toxicities were decreased lymphocyte count (50.8%), decreased neutrophil count (42.4%), and decreased white blood count (33.9%). Only 3 patients (5%) had grade 3 diarrhea during the treatment period. Conclusions: This study showed the modest efficacy and manageable toxicity profile of nal-IRI+5-FU/LV in platinum-refractory locally advanced or metastatic H&N or esophagus cancer patients. Clinical benefits including complete tumor response were noted in H&N patients. The role of this regimen in selective patients and the efficacy of combination with immunotherapeutic agents warrant further explorations. Clinical trial information: NCT03712397.