OBJECTIVES: SCLC is associated with limited treatment options and poor survival outcomes. This SLR aimed to understand the clinical unmet need of relapsed SCLC by reviewing real-world treatment outcomes of 3L+ SCLC in North American and European populations.

METHODS: Per the specified protocol, databases (MEDLINE, Embase, and Cochrane Library) were searched on 9^th May 2022 for literature published in the past 10 years (conference abstracts past 5 years). The search included any real-world evidence study design (for example, prospective and retrospective cohort and cross-sectional studies). Dual data screening and extraction were conducted using prespecified templates. Efficacy data including overall survival (OS), progression-free survival (PFS) and objective response rate (ORR) were summarised.

RESULTS: 20 studies were identified, with the majority of studies conducted in Europe (n=13); other studies were conducted in the US (n=4), multinational (n=2) and Canada (n=1). Most studies (n=15) were based on small sample sizes (less than 100 patients), and all but one study followed patients from 3L. Treatments varied widely, with only eight studies reporting on outcomes for treatments recommended by the European Society for Medical Oncology guideline for recurrent SCLC. Across studies reporting outcomes for systemic treatments median OS ranged between 2.7 months and 7.0 months. Median PFS ranged between 1.3 to 3.4 months, and ORR ranged between 7.7% to 21.3%, respectively. The poorest outcomes were observed in patients who were on best supportive care, with median OS ranging between 0.90 to 1.1 months.

CONCLUSIONS: 3L+ SCLC patients have a dismal prognosis and are at high unmet need of new treatment options. The results highlight the challenge of conducting a randomised trial, given the lack of standard of care therapies in this setting.