A phase 3 trial of rovalpituzumab tesirine vs topotecan in patients with advanced small cell lung cancer following frontline platinum-based chemotherapy

Abstract

Background: Small cell lung cancer (SCLC) represents ∼15% of lung cancers. Patients (pts) are staged with limited or extensive stage disease (ES). ES standard therapy consists of a platinum-based therapy + a second agent (etoposide). Initial response rates are high but not durable. Treatment for relapsed pts is limited, but includes topotecan. However, efficacy of topotecan is suboptimal and there is a high unmet need in this population. Delta-like protein 3 (DLL3) is an atypical Notch receptor family ligand identified as a target in SCLC and neuroendocrine carcinomas (NECs). DLL3 is highly expressed in SCLC and NECs but not normal tissue. Rovalpituzumab tesirine (Rova- TTM) is an antibody-drug conjugate composed of a DLL3-targeting IgG1 monoclonal antibody tethered to a toxic DNA crosslinker. Rova-T has antitumor activity in relapsed ES SCLC pts, and was well-tolerated1. Thus, we are investigating Rova-T vs topotecan as a 2nd line therapy in advanced SCLC. Trial design: This is a Phase 3, randomized, open-label, multicenter study (NCT03061812) to assess efficacy, safety, and tolerability of Rova-T vs topotecan. Approximately 411 pts will be enrolled and randomized 2:1 between 2 arms. Arm A regimen: 0.3 mg/kg Rova-T intravenous (IV) on Day 1+ 8mg dexamethasone orally, twice daily on Day -1, 1 and 2 of a 42-day cycle; administered for 2 cycles with up to 2 additional cycles permitted. Arm B: 1.5 mg/m2 topotecan (or per local label) IV on Days 1-5 of each 21-day cycle; administered until disease progression. Pt eligibility: ≥ 18 years; confirmed, advanced/metastatic SCLC with first disease progression following frontline standard therapy; DLL3-high tumor expression; ECOG 0-1; no prior exposure to a pyrrolobenzodiazepine-based drug or topotecan, irinotecan, or other topoisomerase I inhibitor. Primary objectives: to determine if Rova-T improves objective response rate and overall survival vs topotecan. Secondary objectives: to assess if Rova- T improves progression-free survival vs topotecan; to compare duration of objective response between arms; and to assess effect on patient-reported outcomes. 1. Rudin et al., Lancet Oncol, 2016.