Bone health
Is Forteo™ too good to be true?
Dr. Susan E. Brown, PhD
Topics covered in this article:
The new osteoporosis drug Forteo™ (teriparatide) is receiving a lot of attention
these days, and many women are wondering if it’s a safe treatment option for them.
Approved by the FDA in 2001, Forteo works to increase new bone formation instead
of halting bone breakdown like some osteoporosis drug therapies, including Fosamax,
Actonel, Boniva, or even estrogen. This means women who take Forteo are actually
building new bone, instead of simply preventing its degeneration.
Forteo has attracted a lot of attention because of the research showing
increases in lumbar spine bone density, hip density, and the significant reductions
in fracture incidence. But if you’re thinking this sounds too good to be true, you
might be right. Unfortunately, the benefits of Forteo, like most pharmaceutical
drugs, do come at a cost. Forteo is not only very expensive, but animal studies
have shown links to bone cancer. In fact, studies on humans were stopped two years
after they were started because of safety concerns.
Let’s take a closer look at this new osteoporosis drug treatment so you can make
an informed decision about Forteo and your bone health.
What is Forteo, and how does it work for my bones?
Forteo is a synthetic replica of a hormone we make in our bodies called parathyroid
hormone (PTH). It’s formulated using bacterial cultures (E. coli) with an amino
acid sequence identical to part of the human parathyroid hormone (PTH).
In the body, natural parathyroid hormone serves to regulate bone metabolism. Through
activation of various bone metabolic pathways, the PTH drug (Forteo) increases the
number of active osteoblasts (bone-building cells), possibly stimulating them to
overactivity. As I mentioned above, this can certainly increase bone density.
Here’s what the research shows:
- In a 19-month study of high-risk osteoporotic women, Forteo increased bone density
by an average 9.7% in the spine and 2.6% in total hip, while the wrist lost bone
density and total body mineral content remained the same.
- Among 1,637 postmenopausal women with severe osteoporosis and one or more vertebral
fractures at baseline, the drug produced a 9.3% absolute fracture risk reduction over
19 months.
- Over 19 months in these same high-risk women, Forteo reduced hip, pelvis, wrist,
rib, humerus, and other fractures by an absolute 2.9%.
Overall, the short-term studies of Forteo for osteoporosis treatment and bone loss
reported above show this drug to reduce fracture risk substantially more than the
bisphosphonate drugs like Fosamax. In these studies, Forteo also increased bone
density more than the bisphosphonates.
Is Forteo safe for you?
Though Forteo may appear to be a good approach to building bone, there are some
major questions regarding safety. In fact, safety studies done on rats have shown
findings of excessive new bone formation as well as bone cancer. Not surprisingly,
the cancer this drug was found to cause in rat studies (osteosarcoma) is a malignancy
often associated with high osteoblast activity and rapid bone growth.
Another key point is that the longest studies of Forteo were only two years in
duration. Why are there only short-term studies on this new drug treatment? Because
in the animal safety studies, Forteo was shown to cause a very high incidence of
osteosarcoma, as well as osteoblastoma (abnormal mass of tissue in bone), and osteoma
(small, benign bone lesions). Even though the drug doses tested were from 3-, 20-,
and at times, 60-fold higher than those used in human medications, malignant bone
tumors were observed at all Forteo doses, with the incidence reaching 40–50% in
the higher-dose groups.
Given this major safety concern, human trials with this osteoporosis drug treatment
were terminated early, and guidelines were set to limit the duration of its use
in humans. In fact, as the manufacturer specifically states, “The safety and efficacy
of Forteo have not been evaluated beyond 2 years (median 19 months in women and
10 months in men). Consequently, the maximum lifetime exposure to Forteo for an
individual patient is 18 months.” The drug was only approved for treatment of osteoporosis
in 2003, so there are no data, in animals or humans, as to whether use of the drug
contributes to longer-term cancer risk.
Additionally, the FDA now requires a “black box” label warning clearly stating the
increased cancer risk shown in rat studies. This warning also makes clear that the
following individuals should not take Forteo: those with an increased risk for osteosarcoma,
which includes patients with Paget’s disease of bone, those with unexplained elevations
of phosphatase, open epiphyses, or prior external beam or implant radiation on the
skeleton.
A short-term solution with a big price tag
Forteo is certainly not a magic bullet for bone loss and osteoporosis. I would say
it is more like a drug of last resort. Aside from the cancer risk, there are several
other considerations to keep in mind if you are considering taking Forteo.
- By my calculations, since its development, studies on this drug have included only
1943 patients. And according to the manufacturer, a study of one year is considered
“long term,” while the maximum length of any study was only two years. So, not only
is Forteo relatively new, but it is also experimental and needs much more testing.
- Forteo is very expensive — the drug costs upwards of $600–700 per month!
- Forteo must be given as a daily self-administered injection, which may be a concern
for some women.
- While there may be significant bone density gains while using Forteo, the research
is clear that these gains are lost once the drug is stopped. In fact, to maintain
bone density gains, antiresorptive drugs such as Fosamax must be used after stopping
Forteo.
There is another way to rebuild strong, healthy bone
We always support women’s choices and can work with you no matter what you’ve decided
on, but thankfully there is another way to increase bone strength and reduce needless
osteoporotic fractures. I’ve worked with countless individuals on building bone
naturally through healthy nutrition, regular exercise, and the support of several
key vitamins and minerals, and our Personal Program for Bone Health is based upon
this approach. This approach does not run the risk of causing cancer, or lead to
excessive new bone formation — in fact, it’s not only safe for a lifetime, it’s
good for the entire body. Working with the body’s natural pathways enlivens human
healing and the body’s regenerative capacity long-term, so that you don’t have to
rely on a bone drug to have healthier bones.
Our Personal Program for Better Bones is a great place to start
The Personal Program for Better Bones promotes natural bone strength and regeneration
with nutritional supplements, our exclusive bone builder formula, dietary and lifestyle
guidance, and optional phone consultations with our Nurse-Educators. It is based
on over 25 years of research and experience and has helped thousands of women reclaim
their bone health.
- To learn more about the Personal Program for Better Bones, go to
How it works.
- To choose the version of the Program that’s right for you, go to
Compare plans.
- To assess your bone health and fracture risk, take our free
Bone Health Profile.
- To start taking control of your bone health today, sign-up for a
risk-free trial.
If you have questions, don’t hesitate to call us toll-free at 1-800-685-3275.
We’re here to listen and to help.
Related to this article:
References & further reading on Forteo™
Original Publication Date: 01/21/2009
Last Modified:
08/17/2009
Principal Author: Dr. Susan E. Brown, PhD