Once-a-Year
Osteoporosis Treatment on the Horizon
Annual injections of a common osteoporosis medication greatly
reduced older women's risk for fractures, according to a report in the New
England Journal of Medicine (NEJM).
The findings could open the door to US
Food and Drug Administration (FDA) approval of once-a-year zoledronic
acid.
"We've been waiting for this for a long time,” says
Paul Brandt, Ph.D., an assistant professor of neuroscience and experimental
therapeutics at Texas A&M Health Science Center College of Medicine in
Houston. “This is really exciting stuff.
"Here we've got something we can give to patients when they're
in the clinic with a 15-minute IV, and it lasts for a whole year," says Dr.
Brandt, who was not involved in the study.
"The FDA hasn't
approved it for a single-year injection, but I hope it will,” he notes. “It
sure is going to be a good kick in the right direction."
Dr. Steven R. Goldstein, at the New York
University School of Medicine, says, "This is a very attractive alternative
for a significant number of people who cannot or will not take traditional
antiresorptive medication.
But this is not for everybody.
“This study was in older people, so in a select group
of patients this would be a very nice alternative but it's not going to be
a sea change, nor should younger people be running towards this methodology," explains
Dr. Goldstein.
The new study was funded by the medication's maker, Novartis
Pharma. One outside expert agreed the new medication formulation could change
the way people care for their bones.
Many women already take bone-preserving pills called oral
bisphosphonates, but they are not for everyone, explains Dr. Nanette Santoro
at Montefiore Medical Center in the Bronx, NY.
"For now, women who do not tolerate oral bisphosphonates
well but who are good candidates will be able to take the medication in a relatively
convenient form," says Dr. Santoro. "For the future, this may be a harbinger
of how this class of medication will be given years from now."
Osteoporosis primarily affects women in their postmenopausal
years, although it can afflict men as well. As bones thin and become more fragile,
they break more easily, causing severe disability and even death.
Bisphosphonates, a class of medications that includes zoledronic
acid, are the most commonly used treatment for osteoporosis. They work by slowing
the body's natural reabsorption of bone.
But there has been one enduring problem with bisphosphonates:
patients don't take the medications as they should.
"The big concern has been in patient compliance," confirms
Dr. Brandt. "The monthly pills run into problems where women start to forget.
It's also a pain to take these drugs. You have to sit upright and there's a
risk of acid reflux, esophageal damage."
Women also have to take the pills with a full glass of water
while fasting.
According to background information in the paper, most women
appear to be taking less than 80 percent of their prescribed pills by 12 months.
Previous research had shown that one annual injection of
zoledronic acid improved bone density for at least one year in postmenopausal
women with osteoporosis.
The current study looks at how well annual injections do
three years out.
Almost 4,000 postmenopausal women were randomly
assigned to receive a single 15-minute infusion of zoledronic acid or a placebo
(inactive
substance) at baseline, and then 12 months and 24 months later. Participants
were followed out to the 36-month point.
Treatment with zoledronic acid reduced the risk of vertebral
fractures by 70 percent (3.3 percent of women in the treatment arm and 10.9
percent of women in the placebo arm suffered such fractures) over three years,
the team reported. It also reduced the risk of hip fracture by 41 percent (1.4
percent of women in the zoledronic acid group vs. 2.5 percent in the placebo
arm).
Meanwhile, nonvertebral fractures, clinical fractures, and
clinical vertebral fractures were reduced by 25 percent, 33 percent, and 77
percent, respectively.
Women in the treatment arm also experienced significant
improvement in bone mineral density and bone metabolism markers.
There was a slight downside to the injections: women in
the zoledronic acid group experienced more incidents of an irregular heart
rhythm called atrial fibrillation. Other side effects were similar in both
groups.
Always consult your physician for more information. |
