Drug Utilization and Medical Cost Study Focusing on Moisturizers in Cancer Patients Treated with Molecular Targeted Therapy: A Retrospective Observational Study Using Data from a Japanese Claims Database

Molecular targeted therapies (MTTs) cause skin disorders in patients with cancer, and moisturizers are useful treatments; however, their actual use and costs are unknown. Our purpose was to examine the use and costs of moisturizers prescribed for xerosis (asteatosis) in patients with cancer treated with MTTs.We used data from a Japanese hospital-based claims database. The index date was the first date of MTT prescription from October 2011 to April 2018 (selection period), and the follow-up period was 1 year from the index date. Patients treated with MTTs during the selection period and who were not prescribed moisturizers in the 6 months before the index date were included as the study cohort. Timing, duration, amount, and costs of the prescribed moisturizers and total medical costs were analyzed.Among the 78,190 patients in the study cohort, 27,906 patients (35.7%) were prescribed moisturizers during follow-up. Moisturizer prescription timing, duration, and volume were inconsistent. The average annual total medical costs for treating patients with MTT who were prescribed moisturizers was JPY 6.165 million (USD 53,797) per patient, and the moisturizer costs were JPY 6033 (USD 53). The number of patients who used moisturizers showed an increasing trend.No consistent patterns were observed for the timing or duration of moisturizer use, which suggests various developmental patterns of skin disorders. Furthermore, medical costs for moisturizers accounted for only a small proportion of the total medical costs required for cancer treatment.