Drug utilization pattern of romosozumab and other osteoporosis treatments in Japan, 2019-2021.

Introduction: Describe real-world treatment of osteoporosis and romosozumab treatment patterns in Japan.

Materials and methods: Data for patients initiating romosozumab or other antiosteoporotic medications between March 01, 2018, and May 31, 2022, were extracted from the Medical Data Vision (MDV) and Japan Medical Data Center (JMDC) databases. Patients were categorized into four cohorts: those who newly initiated romosozumab within the first (MDV: n = 4782; JMDC: n = 2578) or second (MDV: n = 3888; JMDC: n = 2446) year after launch and those who initiated teriparatide (TPTD; MDV: n = 14,576; JMDC: n = 8259) or non-TPTD antiosteoporotic medications within the first year of romosozumab launch (MDV: n = 352,142; JMDC: n = 185,785).

Results: Mean age, sex, baseline cardiovascular history, comorbidities, and concomitant medications were similar across cohorts. In the MDV database, fracture history was higher in the romosozumab year-1 (59.3%), year-2 (64.1%), and TPTD (65.5%) cohorts versus the non-TPTD cohort (24.4%). Similar rates were identified in the JMDC database: romosozumab year-1 (64.7%), year-2 (66.6%), TPTD (67.5%), and non-TPTD (27.8%). Vertebral fractures were most common in all cohorts. 12-month romosozumab discontinuation varied between the year-1 and year-2 cohorts in MDV (62.4% and 58.8%) and JMDC (57.1% and 52.7%), whereas mean number of injections remained consistent (MDV: 9.7 and 9.8; JMDC: 7.3 and 7.8). Romosozumab persistence was lower in year-1 versus year-2 (MDV: 37.6% and 42.9%; JMDC: 41.2% and 47.3%).

Conclusion: Patients initiating romosozumab and TPTD had a high fracture history. Given the dual effects of promoting bone formation and suppressing resorption, improving romosozumab adherence and persistence over time may be important for antiosteoporotic therapy.