FDA Panel Says 'No' to Osteoporosis Drug

A joint FDA advisory committee voted 9-12 on Tuesday against the continued marketing of calcitonin salmon products for preventing osteoporotic fractures, citing limited efficacy and a slight risk of cancer.

Calcitonin salmon, while beneficial to a small number of patients, has shown limited effectiveness in general in treating osteoporosis of women 5 years after menopause, members of the FDA's advisory committees on reproductive health drugs and on drug safety and risk management said.

Combine that limited effectiveness with an increased risk of cancer that the FDA has spotted after more than 2 decades of use, and the two factors led a majority of members at the joint meeting to vote against its widespread use.

Calcitonin derived from salmon was first approved to treat osteoporosis in late 1984. While nasal spray is the most common formulation available, there are several others in development, the agency said.

The FDA said Tuesday that the drug's safety profile has remained relatively stable since that first approval -- until lately, when an increased risk of cancer was detected in trials for a new oral formulation.

Calcitonin is a naturally occurring hormone involved in the process of bone building. Calcitonin derived from salmon has become a human drug because it's more potent and has a longer half-life.

"The potential for a cancer risk with calcitonin salmon therapy cannot be ignored," the FDA told committee members in briefing documents released ahead of the meeting. "The majority of all calcitonin salmon trials showed an increased risk estimate."

After the cancer risk was detected, the FDA reviewed more than 20 clinical trials involving oral and nasal-use products and found a slight, but consistent risk of cancer -- including melanoma -- in the calcitonin salmon study groups.

The potential cancer risk drew the attention of the FDA when it combined with a lack of efficacy. The FDA said the drug hasn't demonstrated a reduction in the risk of reducing fractures. For example, a 5-year, double-blinded, placebo-controlled trial found calcitonin salmon reduced the risk of fracture in only one of the five treatment groups in the study.

So when the heightened risk of cancer is considered, the FDA wanted to seek the opinion of the two advisory committees about the overall use of the drug and not just for the new formulation, whose application is still pending.

Many of the 12 panelists who voted against continued use of the drug admitted it has a small place for limited use in some patients who can't tolerate other osteoporosis drugs.

"I do see there is a role for calcitonin in my clinical practice," Mary Ruppe, MD, program director of Methodist Hospital's endocrinology fellowship in Houston, said following her No vote. "However, it is a very niche population."