In part one of the phase II/III RESILIENT trial, led by Luis Paz-Ares, researchers evaluated outcomes of second-line treatment with liposomal irinotecan in patients with small cell lung cancer (SCLC) who had disease progression during or after first-line platinum-based chemotherapy. According to the report, published in Cancer, “overall, no new safety signals were identified with liposomal irinotecan, and antitumor activity was promising.”
The first phase of the RESILIENT trial was comprised of dose-exploration and dose-expansion in a total cohort of 25 patients with SCLC. The primary objectives of the trial were to define the safety and tolerability profiles, and to identify a recommended dose. Primary efficacy endpoints were the objective response rate (ORR), progression-free survival (PFS), and overall survival (OS).
An initial dose of intravenous liposomal irinotecan 85 mg/m2 was judged not tolerable after exploration in five patients. Twelve patients received a 70 mg/m2 dose, which was deemed tolerable and used for the dose expansion phase, where 13 additional patients also received the indicated dose. Among these 25 patients, ten experienced grade III or higher treatment-related, treatment-emergent adverse events (TEAEs), the most common of which were diarrhea and neutropenia. Three patients experienced serious treatment related TEAEs, of which two died. Regarding efficacy, the ORR was 44% (95% confidence interval [CI], 24.40–65.07) and the median PFS and OS were 3.98 (95% CI, 1.45–4.24) and 8.08 months (95% CI, 5.16–9.82), respectively.
Given their results, the authors posited that “further evaluation of the efficacy and safety of liposomal irinotecan monotherapy at the recommended dose of 70 mg/m2 is warranted,” and pointed to the ongoing part two of the RESILIENT trial.