More than one-fifth of patients using a testosterone gel sold by Auxilium Pharmaceuticals Inc. developed heart problems in a study of mobility-impaired men aged 65 and older.
The study found that 23 of 106, or 22 percent, of men getting the gel, Testim, had heart-related side effects such as chest pain, heart attack, stroke, or elevated blood pressure, according to a report published today in the New England Journal of Medicine. Of the 103 men who got a placebo, just five, or 5 percent, had similar adverse effects, the researchers at Boston University Medical Center found.
Testosterone supplements have been shown to boost muscle mass and strength in aging men, the report said. This trial was designed to see if Testim could improve physical function in men with limited mobility. While the testosterone group did show improvement in their ability to climb stairs and do leg presses, the study was halted early because of concern that the drug may be linked to cardiovascular problems.
“Physicians and patients, especially older men, should consider this study’s findings on adverse effects along with other information on the risks and benefits of testosterone therapy,” the study authors said in a statement. They urged further research “to clarify the safety issues raised by this trial.”
Testim had worldwide revenue of $160.5 million last year, 98 percent of the company’s total, according to a regulatory filing. Auxilium rose 65 cents, or 2.8 percent, to $23.50 in Nasdaq Stock Market composite trading at 4 p.m. New York time. The stock has declined 25 percent in the last 12 months.
Testim, a skin gel, was approved in October 2002 as a testosterone replacement therapy for men with hypogonadism, a condition in which the body doesn’t produce enough of the hormone. Hypogonadism can cause fatigue, infertility, decreased sex drive and loss of bone mass. Testim competes with Androgel, sold by Abbott Park, Illinois-based Abbott Laboratories.
The study, which was discontinued in December, was funded by a grant to Shalender Bhasin, the chief of endocrinology at Boston Medical Center, from the National Institute on Aging, part of the U.S. National Institutes of Health. Auxilium donated the product and wasn’t involved in the study design or execution, according to the report.
Twice as many men in the Testim group had complications requiring medical evaluations compared with the placebo group, according to the report. Ten men had full-blown cardiac events, including two confirmed heart attacks and one death.
Bhasin and his co-authors said aspects of this study make it difficult to draw conclusions about the safety of Testim. The main limitations they cited were the small size of the clinical trial and the nature of the population being studied.
Patients in the study were frail, had higher rates of chronic disease than the general population, and had an average age of 74, according to the study. In contrast, 95 percent of patients getting Testim in the real world are under 75, said Eboo Versi, vice president of drug safety and medical affairs of Malvern, Pennsylvania-based Auxilium.
Another factor that makes the findings not apply to other men is that some study participants were given 15 grams of Testim a day, while the medicine’s label recommends starting patients on 5 grams and going up to 10 grams only if needed. That dosing was “totally off label,” Versi said in a telephone interview today.
Overall in the study, 16 men received the highest dose or 15 grams of testosterone, while 61 received 10 grams and 29 received 5 grams, according to the journal report.
Another study of testosterone gel in men over 65, published online Jan. 8 in the Journal of Clinical Endocrinology & Metabolism, found no significant difference in cardiac events between the treatment group and those who got a placebo gel. Auxilium analyzed its Testim registration studies and didn’t find any increased risk of cardiovascular events, Versi said.
“We obviously want to get ahold of this data and we will analyze it and share with the FDA our findings,” he said. “If there was a concern, we’d very much want to ensure we have a change in our label, but for now this study is looking like the odd man out.”
Another study published in the same journal on June 16 found that low testosterone levels in older men are less common than doctors previously thought, with only 2 percent of men from 40 to 80 suffering from hypogonadism.