This article is more than 5 years old. Information may no longer be current.
Odanacatib increased BMD in postmenopausal women
Click Here to Manage Email Alerts
Results from the phase 2 study on an investigational cathepsin inhibitor currently in development showed that the medication increased bone mineral density in postmenopausal women who were previously treated with a popular bisphosphonate.
Odanacatib (Merck) is a selective inhibitor of the collagenase cathepsin-K enzyme, which is thought to be responsible for the degradation in bone resorption.
In a randomized, double blind, placebo-controlled, multicenter, 2-year phase 2 trial, researchers examined the use of odanacatib in postmenopausal women (n=243) who were previously treated with daily or weekly alendronate sodium (Fosamax, Merck) for more than 3 years. Patient BMD T scores measured –2 to –3.5 at the spine or hip.
Researchers randomly assigned the patients to weekly placebo or odanacatib 3 mg, 10 mg, 25 mg or 50 mg plus vitamin D3 and calcium. According to a press release, the study aimed to determine the effects of odanacatib 50 mg once weekly based on the following:
- Femoral neck BMD change from baseline compared with placebo over 24 months;
- Femoral neck BMD compared with baseline over 24 months;
- BMD at hip trochanter, total hip, lumbar spine and distal forearm;
- Biochemical markers of bone resorption and formation at months 12 and 24;
- Clinical and laboratory assessment of safety and tolerability.
Data indicate all women were randomly assigned by year 3. Women who received placebo or odanacatib 3 mg in years 1 and 2, placebo in year 3, received odanacatib 50 mg in years 4 and 5. The other patients continued with year 3 treatments.
According to data, women receiving odanacatib 10 mg to 50 mg for 5 years experienced spine and hip BMD increase over time.
Additionally, patients administered odanacatib 50 mg for 5 years (n=13) saw a mean lumbar spine BMD percent change from baseline of 11.9% (95% CI, 7.2-16.5) vs. –0.4% (95% CI, –3.1 to 2.3) in patients switched from odanacatib 50 mg to placebo after 2 years (n=14).
The most common adverse events in the odanacatib group vs. placebo included urinary tract infection (11.5% vs. 16.5%), back pain (11.5% vs. 9.9%), arthralgia (9% vs. 9.9%), fractures (4.9% vs. 13.2%), bronchitis (5.7% vs. 4.1%), nasal pharyngitis (3.3% vs. 5.8%) and upper respiratory infection (4.1% vs. 0.8%). However, researchers wrote that the therapy was well tolerated.
Furthermore, the researchers found that women receiving combinations of odanacatib (10 mg to 50 mg) for 5 years showed improvements in spine and hip BMD, with greater reductions in bone resorption compared with bone formation markers. Once discontinued, the women saw a reversal of treatment effects, researchers said.
In a press release, Merck said the company plans to submit regulatory applications for odanacatib to the FDA in the first half of 2013.
Click Here to Manage Email Alerts