Romosozumab Prescribing in Relation to Cardiovascular Disease History in Japan: A Nationwide Claims Database Study

Concerns regarding the cardiovascular safety of romosozumab have led to regulatory restrictions and precautionary guidance worldwide. In Japan, although a history of myocardial infarction or stroke is not a formal contraindication, physicians are cautioned to avoid prescribing romosozumab to patients who have experienced these events within the previous year. How this caution is reflected in real-world clinical practice remains insufficiently described. We conducted a nationwide descriptive study using the National Database of Health Insurance Claims of Japan, which covers nearly the entire Japanese population. Patients who initiated romosozumab between March 2019 and March 2023 were identified. Cardiovascular disease (CVD) history was defined as documented myocardial infarction or stroke within 360 days prior to initiation. For comparison of prescribing patterns, users of other anti-osteoporosis medications (AOMs) were also examined. Temporal trends in the prevalence of CVD history and associations with treatment discontinuation were assessed. A total of 311,585 patients initiated romosozumab during the study period. CVD history was present in 11.7% of men and 7.9% of women at initiation. These proportions were lower than those observed among other AOM users (16.4-17.6% in men, 8.9-11.5% in women) and declined across successive fiscal years. Patients with CVD history had higher probabilities of treatment discontinuation, particularly among women. This nationwide claims-based study provides real-world romosozumab prescribing patterns in relation to CVD history in Japan. Continued efforts to enhance awareness and adherence to cardiovascular risk precautions are warranted until the cardiovascular safety profile of romosozumab is more clearly established.