Real-world outcomes associated with afatinib use in patients with solid tumors harboring NRG1 gene fusions

Objectives: Neuregulin-1 (NRG1) fusions may drive oncogenesis via constitutive activation of ErbB signaling. Hence, NRG1 fusion-driven tumors may be susceptible to ErbB-targeted therapy. Afatinib (irreversible pan-ErbB inhibitor) has demonstrated activity in individual patients with NRG1 fusion-positive solid tumors. This study collected real-world data on demographics, clinical characteristics, and clinical outcomes in this patient population. Materials and Methods: In this retrospective, multicenter, non-comparative cohort study, physicians in the USbased Cardinal Health Oncology Provider Extended Network collected data from medical records of patients with NRG1 fusion-positive solid tumors who received afatinib (afatinib cohort) or other systemic therapies (nonafatinib cohort) in any therapy line. Objectives included demographics, clinical characteristics, and outcomes (overall response rate [ORR], progression-free survival [PFS], and overall survival [OS]). Results: Patients (N = 110) with a variety of solid tumor types were included; 72 received afatinib, 38 other therapies. In the afatinib cohort, 70.8 % of patients received afatinib as second-line treatment and Eastern Cooperative Oncology Group performance status (ECOG PS) was 2-4 in 69.4 % at baseline. In the non-afatinib cohort, 94.7 % of patients received systemic therapy as first-line treatment and ECOG PS was 2-4 in 31.6 % at baseline. In the afatinib cohort, ORR was 37.5 % overall (43.8 % when received as first-line therapy); median PFS and OS were 5.5 and 7.2 months, respectively. In the non-afatinib cohort, ORR was 76.3 %; median PFS and OS were 12.9 and 22.6 months, respectively. Conclusion: This study provides real-world data on the characteristics of patients with NRG1 fusion-positive solid tumors treated with afatinib or other therapies; durable responses were observed in both groups. However, there were imbalances between the cohorts, and the study was not designed to compare outcomes. Further prospective/retrospective trials are required.