Real-world use, effectiveness, and safety of second-line lurbinectedin monotherapy in small cell lung cancer.

Aim: Assess real-world outcomes of lurbinectedin and other second-line treatments (OST) in adults with small cell lung cancer that progressed on/after chemotherapy.

Patients & methods: US-based electronic medical data from Flatiron Health (01/01/2013-03/31/2022) were used. Baseline characteristics, including chemotherapy-free interval (CTFI), in patients receiving lurbinectedin or OST were balanced using propensity score (PS) overlap weighting.

Results: Before PS-weighting, median (95% confidence interval [CI]) real-world progression-free survival (rwPFS) was 2.46 months (2.07-2.73), and real-world response rate (rwRR) was 27.5% (23.1-32.4) in 374 eligible lurbinectedin-treated patients. After PS-weighting, median rwPFS was 2.73 months (2.33-3.32) and 2.53 months (2.23-2.99) in 291 lurbinectedin-treated patients and 261 OST-treated patients, respectively; rwRR was 30.9% and 31.8% (relative risk, 0.97). Lurbinectedin demonstrated numerically improved median rwPFS (3.61 versus 3.02 months) and rwRR (38.7% versus 36.1%) versus OST in patients with CTFI ≥90 days but not in patients with CTFI <90 days (2.00 months both; 20.5% versus 26.1%). Lurbinectedin-treated patients reported less grade ≥3 thrombocytopenia (11.7%) and anemia (6.5%) versus OST (27.2% and 20.3%, respectively); prevalence by CTFI status were similar.

Conclusion: Lurbinectedin demonstrated comparable real-world effectiveness with OST with a favorable safety profile; however, these findings are limited by small sample size.