WASHINGTON — A rapid-delivery transdermal teriparatide patch is more effective at increasing total hip bone mineral density than is a daily subcutaneous teriparatide injection, based on the results of a phase II study.
Furthermore, the patch is just as effective as the injection at building lumbar spine bone mineral density (BMD), Dr. Felicia Cosman said at an international symposium sponsored by the National Osteoporosis Foundation.
The phase II trial, sponsored by Zosano Pharma Inc., found that the 40-mcg patch increased total hip BMD by 1.3% in 24 weeks, whereas the daily injected dose failed to increase total hip BMD at all.
The patches are loaded into a cylindrical delivery system. The patient places the patch by pressing the open end of the device against the skin. Once it has adhered to the skin, the quarter-sized patch rapidly delivers the drug, which reaches its peak plasma concentration within just a few minutes. Delivered this way, 40% of the drug is bioavailable.
The placebo-controlled, multidose trial included 165 postmenopausal women (mean age, 64 years). They were randomized to the daily injection (20 mcg), to a placebo patch, or to an active patch of 20, 30, or 40 mcg teriparatide.
After 24 weeks of treatment, all the active comparators resulted in significant BMD gains at the lumbar spine, relative to placebo. Patients using the 40-mcg patch gained a mean of 5% at the lumbar spine. Patients using the 30-mcg patch and taking the daily injections gained a mean of 3.5%, whereas those using the 20-mcg patch gained a mean of 2%. Patients using a placebo patch lost a mean of 0.5% BMD from baseline, reported Dr. Cosman, medical director of the clinical research center at Helen Hayes Hospital in West Haverstraw, N.Y.
Patients using the 40-mcg patch also showed a significant 1.3% increase in total hip BMD. Those using the 30-mcg patch gained 0.5% at the total hip. Patients using the 20-mcg patch, and those using the injectable drug, showed no significant gain in total hip BMD. The placebo patients experienced a BMD decrease of 0.6%.
Adverse events were localized and transient, and included mild to moderate erythema at the patch site.
Dr. Cosman is a paid consultant to Zosano.