Erlotinib and patterns of pharmacogenomic (PGx) testing.

Abstract

182 Background: Erlotinib is an oral oncology drug that costs approximately $5,000 per month. Both the NCCN Guidelines (since March 2011) and ASCO (since April 2011) recommend PGx testing for tumor epidermal growth factor receptor (EGFR) mutation in patients with advanced non-small cell lung cancer prior to erlotinib use in the first line setting. Insight into early utilization patterns of PGx testing is crucial as new reimbursement methods, care models and evidence-based clinical pathways are developed. Methods: Using integrated medical and pharmaceutical data from four Blue Cross Blue Shield plans, we retrospectively identified members who received erlotinib between 01/2011 and 06/2011 and identified the date of the first erlotinib claim (index date). A new erlotinib user was defined as having no erlotinib claims filed in the prior 180 days. Among members who received erlotinib, medical claims were queried for the presence of ICD-9 codes for malignant neoplasm of trachea, bronchus and lung and for any current procedure terminology (CPT) code indicating PGx testing and other chemotherapy in the prior 24-month period and 1-month post the index date. Total paid amounts from all PGx test codes were obtained. The closest PGx testing date to the index date was used to calculate days between PGx testing and index date. Further analyses examining lines of therapy, monthly patterns of erlotinib usage and PGx testing pre- and post-guidelines recommendations, as well as a description of differences in utilized PGx CPT codes per individual patient, were performed. Results: Among 3,357,936 members insured, 125 (40 per million) received erlotinib, and 102 (81.6%) of those patients had a lung cancer diagnosis. Sixty (48%) were new erlotinib users, and 47 had a diagnosis of lung cancer. Of these, 36 (76.5%) had a PGx CPT code claim. The time between the PGx test and erlotinib start ranged from 4 days to 22 months. A total of $30,391 was spent on all PGx testing with an average of $844 per member tested. Conclusions: In a privately insured cohort of members who newly initiated erlotinib for lung cancer, 23.5% had no prior PGx testing. There is an opportunity for consensus guidelines, care management programs and a single PGx CPT code to possibly reduce variation regarding PGx testing patterns.