Efficacy and safety of rovalpituzumab tesirine in patients With DLL3-expressing, ≥ 3rd line small cell lung cancer: Results from the phase 2 TRINITY study.

8507Background: Small cell lung cancer (SCLC) accounts for ~15% of lung cancer with no approved therapies in ≥ 3rd line (3L) patients (pts). In 3L pts, historical data demonstrate a median overall survival (mOS) of 4.7 mo and a best overall response of 18%; no historical data exist for objective response rate (ORR). Rovalpituzumab tesirine (Rova-T™) is an antibody-drug conjugate targeting Delta-like 3 protein (DLL3), an atypical Notch ligand that is highly expressed in SCLC but not normal tissue. A Ph1 study showed that Rova-T has antitumor activity in pts with recurrent SCLC and high DLL3 expression, and a manageable safety profile. Methods: TRINITY was an open-label, single-arm, Ph2 study of Rova-T in adult pts with DLL3-expressing SCLC (NCT02674568). Eligibility: ≥ 2 prior systemic regimens including ≥ 1 platinum-based regimen; ECOG 0-1; stable CNS disease. Pts received 0.3 mg/kg Rova-T intravenously on Day 1 of a 6-week cycle for 2 cycles. DLL3-high (hi) pts had ≥ 75% tumor cells positive by immunohis...