Postmarketing Surveillance Study of Erlotinib in Japanese Patients With Non-Small-Cell Lung Cancer (NSCLC) An Interim Analysis of 3488 Patients (POLARSTAR)

Introduction: Interstitial lung disease (ILD) is an adverse drug reaction (ADR) of concern in Japanese patients with non-small-cell lung cancer (NSCLC) receiving erlotinib. To investigate erlotinib safety and efficacy in Japanese patients, a large-scale surveillance study was implemented. Methods: All patients with recurrent/advanced NSCLC receiving erlotinib in Japan were enrolled (December 2007-October 2009). During the 12-month observation period, adverse-event data were collected; any adverse event where erlotinib could not be excluded as a causative factor was termed an ADR. An independent review committee assessed ILD-like events. Overall survival and progression-free survival were also assessed. Interim data were analyzed for patients registered before June 30, 2008. Results: In total, 10,708 patients were enrolled, 3743 by June 30, 2008, with data available for 3488 patients. Overall ADR incidence was 81.8% (mostly grade 1/2); skin disorders (68.5%) including rash (63.0%) were most common. However, 81.8% of patients who experienced rash recovered or improved. ILD-like events, diagnosed by local physicians, were reported in 189 patients. The independent review committee confirmed ILD (all grades) in 158 patients (4.5% of interim population) with a mortality rate of 1.6% (55 patients). Significant ILD risk factors included concomitant or previous ILD, smoking history, concomitant or previous lung infection, and Eastern Cooperative Oncology Group performance status 2 to 4. Median overall survival and progression-free survival were 260 and 64 days, respectively. Conclusions: These interim data support the clinical benefits of erlotinib in Japanese NSCLC patients with no new safety signals. The risk/benefit balance for erlotinib in recurrent/advanced NSCLC remains favorable.