Real-World Treatment Patterns and Outcomes Among Patients with Basal Cell Carcinoma Following First-Line Hedgehog Inhibitor Discontinuation

INTRODUCTION: Until recently, patients discontinuing first-line (1L) hedgehog inhibitors (HHIs) for basal cell carcinoma (BCC) had few subsequent treatment options. The objective of this study was to describe the treatment journey and prognosis of patients discontinuing 1L HHI for BCC. METHODS: This was a retrospective cohort study of patients with BCC who discontinued 1L HHI treatment in The US Oncology Network between 1 January 2012 and 1 January 2019 (with follow-up until 1 May 2020). Two cohorts were identified: patients who initiated a second-line (2L) treatment (2L initiators), and patients with 1L progression or toxicity without pathology-confirmed complete response who did not initiate 2L treatment (2L non-initiators). Patient demographics, treatment characteristics, and outcomes are reported for each cohort. RESULTS: Among 115 patients with BCC who received 1L HHI treatment, 63.5% (n = 73/115) discontinued 1L HHIs. Of those, 50.7% (n = 37/73) discontinued because of documented toxicity or progression, without evidence of a complete response. We identified 4 patients who initiated 2L systemic treatment (median age 68.7 years, 100.0% female) and 15 patients who were eligible for the 2L non-initiator cohort (median age 80.2 years, 20.0% female). Median 1L HHI duration was 6.8 months (range 1.9–20.6 months) for the 2L non-initiator cohort and 8.6 months (range 6.8–42.2 months) for 2L initiators. At the end of follow-up, among 2L non-initiators (median follow-up duration 9.7 months), 40.0% were lost to follow-up, 33.3% had died, 20.0% continued observation, and 6.7% transitioned to an academic medical center or hospital; among 2L initiators (median follow-up duration 6.3 months), 50.0% were lost to follow-up, 25.0% had died, and 25.0% continued observation. CONCLUSIONS: Following 1L HHI discontinuation, lack of standardized care and suboptimal outcomes were observed, including limited receipt of 2L treatment. Further studies are necessary to evaluate the impact of newer BCC treatment options.