MAUI, HAWAII – The investigational bone-building agent romosozumab provided the therapeutic highlight in the field of osteoporosis during the past year, Dr. Martin J. Bergman said at the 2016 Rheumatology Winter Clinical Symposium.
Romosozumab is a monoclonal antibody directed against sclerostin, a glycoprotein that prevents mesenchymal cells from becoming osteoblasts. By inhibiting sclerostin, romosozumab promotes osteoblast production. The result is increased bone mineral density and bone formation coupled with decreased bone resorption, providing physicians with a promising new avenue for rapidly building strong bone, explained Dr. Bergman of Drexel University in Philadelphia and chief of the section of rheumatology at Taylor Hospital in Ridley Park, Pa.
Bruce Jancin/Frontline Medical News
Dr. Martin J. Bergman
Romosozumab caught his eye in a 12-month randomized trial presented last fall at the annual meeting of the American College of Rheumatology. The 430 postmenopausal participants were assigned to blinded romosozumab at 210 mg delivered by subcutaneous injection once per month, blinded placebo, or open-label teriparatide (Forteo). The primary endpoint in this secondary analysis was change in bone strength as measured using the Food and Drug Administration–approved method of finite element analysis based upon quantitative CT imaging.
Romosozumab boosted bone strength at the spine by 27.3% at 12 months, compared with a 3.9% reduction from baseline with placebo and an 18.5% increase with teriparatide. At the hip, romosozumab delivered a 3.6% increase in bone strength versus no significant change from baseline in the other two study arms. Thus, romosozumab increased bone strength both in the cortical and trabecular compartments even more than did teriparatide, the most potent drug currently available for building bone mass.
“The numbers are very impressive,” Dr. Bergman observed. “Trabecular bone, cortical bone, whole bone – across the board, we haven’t seen similar numbers before. I think this is going to be a very exciting new approach to the treatment of osteoporosis. We need to keep an eye on this.”
Romosozumab, which is being codeveloped by Amgen and UCB, is now in phase III testing.
The other big news in osteoporosis is that later this year the ACR will undertake a revision of its 2010 guidelines for the prevention and treatment of glucocorticoid-induced osteoporosis (Arthritis Care Res [Hoboken]. 2010 Nov;62[11]:1515-26).
Among the actions that need to be taken are the incorporation of denosumab (Prolia) and ibandronate (Boniva) into the treatment recommendations, as well as clarification of the recommendation for supplemental calcium in light of recent evidence of an association between high serum calcium and increased cardiovascular risk. Most of the lifestyle modification recommendations in the current guidelines are supported by a weak level of evidence C, meaning “expert opinion,” and the hope is that the evidence has become stronger since 2010, he said.
Dr. Bergman reported having no financial conflicts regarding his presentation.