How One Class of Bisphosphonates Could Predict Vertebral Fractures

Using biomarkers to assess the efficacy of existing bisphosphonate drugs in predicting fracture risk could pave the way for improved osteoporosis treatment, according to a new study.

Currently, little analysis exists into how bisphosphonate drugs can relate bone turnover markers to fracture reduction. With the cost of drug development so high - and with the time to get new drugs approved so long - researchers looked into how available drugs can help reduce fracture risk.

In a Sept. 19 presentation at the America Society of Bone Mineral Research conference, lead study author Douglas Bauer, M.D., from the University of California-San Francisco, discussed how biomarkers, such as blood and urine, can help identify how one class of bisphosphonates can predict vertebral - but not non-vertebral - fractures.

Based on the National Institutes of Health Bone Quality project, investigators analyzed data on more than 120,000 participants from 11 clinical trials, including bone turnover markers, dual-energy X-Ray absorptiometry and fracture outcomes. They recorded baseline data from 2,268 individuals with vertebral fractures, 3,286 with non-spine fractures (including 514 hip fractures), and 6,729 N-telopeptide of type 1 collagen fractures.

Researchers compared the mean effect of the bisphosphonate to the placebo over a three-to-four-year period. Results indicate there’s a high statistically-significant relationship between short-term change and bone markers for vertebral fractures compared to the placebo group (p=0.005, r=0.84). However, no such strong relationship exists for non-vertebral fractures. The findings suggest that non-fragile factors, such as falling, come into play for non-vertebral fractures.

For instance, for two hypothetical bisphosphonates with 10 percent versus 30 percent reductions in bone-specific alkaline phosphatase, the model predicted a 19 percent versus 66 percent reduction in vertebral fractures (r2-0.84, p=0.001). The relationship is weaker and not significant for non-vertebral fractures. The comparable risk reductions were 12 percent versus 21 percent (r2=0.06, p=0.27).

Ultimately, Dr. Bauer told Rheumatology Network, the study results can, hopefully, be useful in developing medications for the same bisphosphonate classes and extending the effects to other populations.

“The hope is that this overall effect can be observed in all anti-absorptive medications that will be developed in the future,” Dr. Bauer said. “Hopefully, all this data will be used to fill in predictive efficacy.”

References:

American Society of Bone Mineral Research 2016

, Abstract 1158: “Bisphosphonate-related Changes in Bone Turnover are Associated with Vertebral, but not Non-Vertebral, Fracture Risk Reduction: A Meta-Regression,” Douglas Bauer, M.D. Sept. 19, 2016.