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.