Responders and non-responders to romosozumab treatment

Romosozumab is an anti-sclerostin antibody drug with potent bone formation-promoting and bone resorption-inhibiting properties. It enhances bone mineral density and has a novel effect in preventing fractures. However, there have been reports of non-responders to romosozumab.

If the least significant change is defined as 3%, only 2-12% of patients with spine osteoporosis are non-responders, and romosozumab is highly effective in this population. Low-type 1 amino-terminal propeptide (P1NP) levels during the early treatment phase are associated with non-responders early in treatment. The researchers found a cutoff value of 50.3 μg/L of P1NP in the first month of treatment. In contrast, hip osteoporosis does not respond (54-57% of the time). Low P1NP levels at the start of treatment increase the risk of non-responders. The cutoff value for P1NP was reported as 53.7 μg/L at the beginning of treatment. However, failure to meet these cutoff values does not necessarily indicate that the patient is a non-responder and does not justify a change in drug administration.

In spine osteoporosis, romosozumab demonstrates high effectiveness, with approximately 2-12% of patients showing no response. However, in hip osteoporosis, approximately 54-57% do not respond to the treatment with romosozumab.