FDA Approves Forteo® for Steroid-Induced Osteoporosis
Three out of every one hundred Americans take Glucocorticoids for medical conditions like asthma, chronic obstructive pulmonary disorder (COPD), lupus and other auto-immune disorders. People of all ages take steroids, so this new approval opens up a new class of patients who could use this besides the normal age-related osteoporosis group, which prompted the FDA to update the language on the black box warning for osteosarcoma.
Glucocorticoids are a class of steroid hormone. A few examples of these are hydrocortisone, prednisone, cortisone, and methylprednisolone. Osteoporosis caused by these medications is the number one cause of medication-induced osteoporosis.
Eli Lily, the manufacturer of Teriparatide, also know by the brand name Forteo® has discovered that the use of Forteo can reverse and slow bone loss seen in these patients taking these desperately needed medications. In a study done by Lily patients saw an increase of bone mineral density from baseline of 7.2% at the lumbar spine, 3.6% at the total hip and 3.7% at the femoral neck after 18 months of treatment.
Forteo is a man-made form of a portion of our body's parathyroid hormone. This hormone, produced daily by the parathyroid gland, is responsible for regulating calcium and phosphate metabolism in our bodies which is critically important in maintaining strong bones.
This is great news for those who need to take these medications, in my opinion, since Forteo is the only osteoporosis medication approved to halt and slow the occurrence of bone loss through new bone growth.
Forteo can not be taken by those patient's whose bones are still growing, like in our pediatric and young adult populations. We know this from the rat studies that were done on this drug prior to 2002 when the drug was first marketed for osteoporosis in both men and women who are at greater risk from fracture due to low t-scores.
This drug has a black box warning on it for osteosarcoma-a type of bone cancer-because during the testing stage on Fisher rats some of the rats treated developed this type of cancer. However, the rats that contracted osteosarcoma did so because they were given 3-60 times the human dose of 20 micrograms from a young age, while their bones were still growing, and given the drug throughout most of their lives. It is not surprising to me that a rat, that is pre-disposed to osteosarcoma anyway, would develop this bone cancer at such a high dose over a prolonged period starting it while they were still young.
Humans can only take 20 micrograms daily for a 2 year period and in the human study none of the participants contracted osteosarcoma at this dose strength or length.
In a second study done by Eli Lily, rats were given a dose comparable to the human dose for a limited period of 18-24 months and only full grown rats were used since they had finished their bone growth. In that study none of the rats contracted osteosarcoma.
The incidence of osteosarcoma in humans, which is considered rare, is 1 in 250,000 and in rats its 1-3 in 1,000. The largest groups of those who contract this type of bone cancer are young children.
Here are some guidelines on who should or shouldn't take Forteo, the classes given for the injection and how to travel with it, to explain this a bit further, if you are considering this type of treatment for osteoporosis and steroid-induced osteoporosis.
Who Shouldn't Take Forteo?
Patients whose bones are still growing shouldn't take Forteo. If the patient has unexplained elevations of alkaline phosphatase, Pagets disease, other metabolic bone diseases besides osteoporosis, primary hyperparathyroidism, history of osteosarcoma, are pregnant or nursing, has renal impairment, hypercalcemia (high calcium levels) or has ever been treated for cancer with radiation to the bone, shouldn't take Forteo.
Who Should Take Forteo?
Patients, both men and women, who are at high risk for fracture, may take Forteo. Other indications for taking Forteo are for those who continue to loose bone mass or fracture while taking an antiresorptive. Also patients who can not take bisphosphonates or who have taken Glucocorticoids and have fractured would also be suitable candidates for Forteo.
How is Forteo Administered?
Forteo comes in a pre-metered dose pen that last for twenty-eight days. The patient injects a 20 microgram dose daily in the thigh or stomach. The pen should be discarded in a sharps container and disposed at a medical waste facility at the end of twenty-eight days even if there is some medication left in the pen. The contents of the pen shouldn't be transferred from the pen to a syringe.
Forteo was very effective for me, but there are some problems I see with this drug which I'll explain.
Forteo is extremely expensive; at $1,000.00 a month and quite a few of the insurance companies do not cover it, or do so with severely high co-pays. For this reason the cost is prohibited for many patients.
Most insurance companies require patients to treat with a bisphosphonate first without success to qualify or have pre-existing fractures and a t-score of -3.0 or below. Some clinicians will prescribe Forteo with a t-score of ≤ -2.5 with a history of fracture. These treatment determinations are based on the discretion of the treating physician. Since we can only take Forteo for 2 years, this means that when the 2 years are completed, the patient needs to immediately start an anti-resorptive to maintain any gains seen with Forteo because many will see a decline in t-scores within several months if this protocol isn't followed. Because of this many who don't want to take a bisphosphonate are left with few options for follow-up treatment after Forteo.
Currently the FDA and insurance companies considers treatment beyond 2 years experimental, but a small group of physicians with patients that have unique medical issues, will try to get a second course of Forteo approved, but the success of getting insurance companies to pay for this has been very minimal, and comes with the understanding that the patient accepts the risk of using a drug that wasn't tested beyond 2 years.
Eli Lily has started a post-surveillance program to follow those who are taking or have finished taking Forteo to track anyone who might contract osteosarcoma. To sign up for this registry call: 1-866-382-6813 (Eli Lily) or go to: www.forteoregistry.rti.org
According to Eli Lily, in on-going tracking, on the issue of bone cancer they say, "Osteosarcoma has been reported rarely in people who took Forteo. It is not known if people who take Forteo have a higher chance of getting osteosarcoma." Could this have occurred anyway independent of Forteo use, you'll have to decide when more information is made available?
Please weigh the risks versus the benefits, with help from your Doctor, to decide if this is the right treatment for you.