LUPER Study Results: Lurbinectedin + Pembrolizumab in Relapsed SCLC

Phase 1 results of the prospective, open-label, uncontrolled, multicenter, phase 1/2 LUPER study (NCT04358237) indicated that the lurbinectedin plus the anti–PD-1 pembrolizumab combination regimen showed promising antitumor activity with a manageable safety profile in patients with relapsed small cell lung cancer (SCLC) and established the recommended phase 2 dose (RP2D) of lurbinectedin + pembrolizumab. Efficacy and safety results of the RP2D in the phase 2 portion of the LUPER study presented at the 2023 ESMO annual meeting are summarized here.

The LUPER study enrolled adult patients who had histologically confirmed SCLC that progressed after first-line platinum-based chemotherapy, no prior exposure to immunotherapy, Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0 to 1, and measurable disease. Eligible patients received lurbinectedin (3.2 mg/m² intravenously [IV] every 3 weeks [Q3W]) in combination with pembrolizumab (200 mg IV Q3W) until disease progression, unacceptable toxicity, or consent withdrawal. The primary end point was confirmed overall response rate (ORR) according to RECIST 1.1, and key secondary end points included investigator-assessed duration of response (DoR), progression-free survival (PFS), overall survival, and safety. Data cutoff date was March 31, 2023.

The study included a total of 28 patients. Median age of the study population was 65.5 years (range, 41-78); the majority were female (46.4%), had ECOG PS of 1 (64.3%), and had a platinum-free interval <90 days (51.9%).

At a median follow-up of 5.7 months, a preliminary ORR of 46.4% was achieved including 2 confirmed complete responses, 11 partial responses, and 4 patients with stable disease for ≥12 weeks; median DoR was 11.4 months and the median PFS was 5.3 months.

The most common grade 3 and 4 treatment-emergent adverse events (TEAEs; >20%) were fatigue, neutropenia, dyspnea, cough, and anemia. The most common any-grade immune-related TEAEs were diarrhea, increase in aspartate aminotransferase/alanine aminotransferase, and increase in blood bilirubin. TEAEs related to the study treatment occurred in 96.4% of patients, and 21.4% of patients experienced a serious TEAE. TEAEs leading to discontinuation of any study drug occurred in 4 patients.

The authors concluded that the combination of lurbinectedin + pembrolizumab is effective and accompanied by a manageable safety profile in second-line treatment of SCLC.

Source:

Blanco AC. Lurbinectedin (LUR) in combination with pembrolizumab (PBL) in relapsed small cell lung cancer (SCLC): the phase I/II LUPER study. Abstract presented at: ESMO Annual Meeting, October 20-24, 2023; Madrid, Spain. Abstract 1989MO.