(Reuters) - Testosterone replacement therapies should be reserved for men with specific medical conditions that impair function of the testicles, an advisory panel to the U.S. Food and Drug Administration concluded on Wednesday.
The FDA is not obliged to follow the advice of its advisory panels but typically does so. The panel also recommended that companies be required to conduct additional studies to assess the cardiovascular risk of their products for patients with age-related low testosterone.
Prescriptions for “Low T,” as low testosterone has been described in television commercials, have soared over the past decade, driven by an increase in use by middle-aged men with lowered testosterone levels related to advancing age.
Symptoms of low testosterone include loss of libido, decreased muscle mass, fatigue and depression.
The panel voted 20-1 in favor of restricting the drugs’ authorization to people with medically related low testosterone, such as a genetic disorder or a tumor.
If implemented, the restriction would mean companies could not market or promote their products for age-related low testosterone, although physicians would allowed to prescribe products “off label” in any way they choose.
Fourteen members of the panel voted in favor of additional safety studies to assess potential cardiovascular risks associated with the drugs in patients with age-related low testosterone.
Four panelists recommended that cardiovascular studies be conducted regardless of the population in which they are used. One member voted against the need for a study. Most panelists said any safety study should be large and randomly controlled, the gold standard for assessing safety and efficacy.
The market for testosterone treatments currently includes skin patches, short-acting injections and topical gels. AbbVie Inc’s AndroGel, the market leader, generated about $1.04 billion in sales in 2013. Other products include Auxilium Pharmaceuticals Inc’s Testim and Eli Lilly & Co’s Axiron.
On Thursday, an FDA advisory panel will consider Rextoro, a product being developed by privately held Clarus Therapeutics Inc. which, if approved, would be the first oral treatment to meaningfully challenge existing treatments.
In a preliminary review of the data published on Tuesday, FDA reviewers said that although the Rextoro drug met the main goal of a clinical trial, a separate analysis by the FDA that accounted for missing data found it was not as effective as it might appear.
In 2013, 2.3 million men received a prescription for testosterone, up from 1.3 million in 2010, according to the FDA. About 70 percent of men prescribed testosterone drugs were between the ages of 40 and 64.
According to an FDA analysis, 21 percent of patients prescribed testosterone drugs did not appear to have had their testosterone concentrations tested before or during treatment, something the agency described as “concerning.”
In February, the consumer watchdog Public Citizen petitioned the FDA to immediately add a black box warning, the most serious available, about heart risks associated with the drugs.
The FDA denied the petition, saying it was still assessing the potential cardiovascular risks of the products. Most panelists said a black box warning would not be appropriate at this time because there was not enough data to assess the level of risk.
Some recommended adding more moderate language to the label noting that the FDA is exploring whether there is a heart risk but that the evidence to date is inconclusive.
Officials for AbbVie argued that there was no evidence of a causal relationship between testosterone replacement therapies and cardiovascular problems, but said more information would be useful and that companies would be willing to discuss changes to the drug labels.
Reporting by Toni Clarke in Washington; Editing by Jim Loney and Peter Cooney