Phase II Study of the Liposomal Formulation of Eribulin (E7389-LF) in Combination with Nivolumab: Results from the Small Cell Lung Cancer Cohort

PURPOSE: E7389-LF is a liposomal formulation of eribulin that contributes to tumor vascular remodeling. The phase II part of this phase Ib/II study assessed the efficacy/safety of E7389-LF in combination with nivolumab in several disease cohorts; herein, we report results from the small cell lung cancer (SCLC) cohort. EXPERIMENTAL DESIGN: Patients with unresectable/measurable SCLC and disease progression with first-line platinum-based chemotherapy with/without an immune checkpoint inhibitor (ICI) were enrolled to receive E7389-LF 2.1 mg/m2 plus nivolumab 360 mg intravenously every 3 weeks. The primary objective of this part was to assess the objective response rate (ORR). Secondary objectives included assessments of safety and progression-free survival (PFS); exploratory assessments included overall survival (OS) and biomarkers. RESULTS: Thirty-four patients were enrolled. By the data cut-off date (May 31, 2022), 29 (85.3%) had discontinued. Efficacy/biomarker analyses included 33 patients (1 had their diagnosis changed postenrollment); the ORR of E7389-LF plus nivolumab was 24.2% [95% confidence interval (CI): 11.1-42.3], the median PFS was 3.98 months (95% CI: 2.63-4.40), and, at a median follow-up of 10.6 months, the median OS was not reached (95% CI: not estimable). Notably, 27 of 33 patients (81.8%) had received an ICI as their prior first-line therapy. Treatment-related, treatment-emergent adverse events occurred in 97.1% (any grade) and 82.4% (grade ≥3) of enrolled patients; the most common event was neutropenia. Changes in vascular and immune-related plasma markers were observed. CONCLUSIONS: E7389-LF 2.1 mg/m2 in combination with nivolumab 360 mg every 3 weeks showed notable antitumor activity as second-line therapy for SCLC; no new safety signals were observed compared with either agent as monotherapy. SIGNIFICANCE: This phase II part of a phase Ib/II study assessed liposomal eribulin (E7389-LF) plus nivolumab in 34 patients with pretreated SCLC; 8 of 33 evaluable patients (including 6/27 pretreated with ICIs) had objective responses. The combination was tolerable; increases in vasculature-related biomarkers tended to correlate with responses.