Liposomal irinotecan as second-line therapy for SCLC is feasible, safe after frontline platinum therapy failure.
Frontline treatment failure of platinum-based therapy may be followed by liposomal irinotecan in SCLC according to data from the first phase of the RESILIENT trial (NCT03088813) presented at the 2020 World Conference on Lung Cancer showing promising antitumor activity and safety with this strategy.
The study authors initiated the 2-part phase 2/3 open-label, single-arm study to assess liposomal irinotecan in patients with SCLC whose disease progressed after receiving platinum-based chemotherapy in the frontline. Treatment options in the second-line setting remain limited but analyzing long-term follow-up data demonstrated that both exploratory doses of liposomal irinotecan were effective and tolerable in patients with SCLC. Patients who were older than 18, had an ECOG performance score of 0 or 1, and had previously progressed on platinum-based treatments were eligible for the study. RESILIENT was designed around 2 doses of liposomal irinotecan to see which was ultimately more effective, either an 85 mg/m2 or 70 mg/m2 dose administered every 2 weeks.
In the first part of the study, 30 patients (median age, 61.5 years) received the study drug. Women accounted for more than half (56.7%) of the trial population. Four of the 5 patients from the 85 mg/m2 cohort had dose-limiting toxicities such as diarrhea and abnormal liver function and were considered to not have tolerated the dose.
The remaining patients (n = 25) were immediately enrolled onto the 70 mg/m2 dose arm. One patient achieved a complete response, 10 patients achieved a partial response, 7 had stable disease, 5 developed progressive disease, and 2 patients were considered not evaluable. The median duration of response in the 70 mg/m2 cohort was 2.99 months and median progression-free survival was 3.98 months (95% CI; 1.45–4.24). Median overall survival reached 8.08 months (95% CI; 5.16–9.82) in this cohort.
Treatment-related adverse effects were consistent with previous safety findings in liposomal irinotecan. However, all patients from both treatment arms have discontinued treatment. Forty percent of the expansion arm experienced one or more grade 3 or higher treatment-related treatment-emergent adverse event (TEAE). The most common grade 3 or higher treatment-related TEAEs were diarrhea (20%), neutropenia (16%), anemia, thrombocytopenia, asthenia, and abdominal sepsis (each 8% of the total patient population).
“Liposomal irinotecan raised no new safety signals in patients with small cell lung cancer and the anti-tumor activity observed was promising, warranting further study,” study author Luis G Paz-Ares, MD, PhD, of the Hospital Universitario 12 De Octubre in Madrid, said in a prerecorded presentation of the data.
Paz-Ares L, Spigel D, Chen Y, et al. RESILIENT part 1: a phase II dose-exploration and dose expansion study of second-line liposomal irinotecan monotherapy in adults with small cell lung cancer. Presented at: 2020 World Conference on Lung Cancer Singapore; January 28-31, 2021; Virtual. Abstract FP10.04