FDA issues safety labeling changes for female sexual dysfunction treatment

The U.S. Food and Drug Administration today issued a safety labeling change order to Sprout Pharmaceuticals for their drug, Addyi (flibanserin), that requires the company to revise important safety information that women and their health care professionals need to have when considering use of the drug. The changes are the result of the FDA's review of postmarketing studies, including one required of Sprout when Addyi was approved in August 2015, to treat acquired, generalized hypoactive sexual desire disorder (HSDD) in premenopausal women, as well as other data.

"The FDA helps ensure that the most current safety information about the use of prescription drugs is accurately reflected in product labeling, giving health care professionals and patients confidence that they are able to make the most informed treatment decisions," said Julie Beitz, M.D. director of the Office of Drug Evaluation III in the FDA's Center for Drug Evaluation and Research's Office of New Drugs. "We recognize that women want access to treatments for female sexual dysfunction, and we are committed to helping ensure approved therapies are safe and effective when taken as indicated and to supporting the development of new therapeutic options for female sexual dysfunction."

At the time of approval, the FDA reviewed data that included several concerning cases of severe hypotension (low blood pressure) and syncope (passing out) when Addyi and alcohol were taken together. As a result, Addyi's labeling currently includes a boxed warning (the strongest warning the FDA requires), which states that alcohol must be avoided in women treated with Addyi. The FDA also required a risk evaluation and mitigation strategy (REMS), which requires that health care professionals who prescribe Addyi and pharmacies that dispense Addyi, must be certified with the Addyi REMS program and that patients must be counseled about the risk of hypotension and syncope. In addition, the FDA required Sprout to further study the interaction between Addyi and alcohol after approval.

Based on the results of postmarketing studies, the FDA has determined that changes must be made to Addyi's labeling to clarify that there is still a concern about consuming alcohol close in time to taking Addyi but that it does not have to be avoided completely. Specifically, the boxed warning, contraindication, warnings and precautions, and adverse reactions sections of labeling are being updated to reflect that women should discontinue drinking alcohol at least two hours before taking Addyi at bedtime or to skip the Addyi dose that evening. Women should not consume alcohol at least until the morning after taking Addyi at bedtime.

The FDA is ordering a safety labeling change requiring Sprout to make these changes because the agency was not able to reach an agreement with the company, which was continuing to request removal of the boxed warning and contraindication about alcohol completely from the product labeling. The FDA determined, based on a careful review of available data, that removing this important safety information was not acceptable for the protection of public health.

"We work diligently with companies to make labeling updates but occasionally are unable to reach agreement. In those rare cases, such as with Addyi today, we have important authorities to compel companies to make safety labeling changes that are critical for the safe use of an approved product. We are taking this action because it is our responsibility to help protect the safety of those who take prescription medicines, which includes helping to ensure that patients are provided access to the most up-to-date information about the drugs they take," continued Dr. Beitz.

The FDA's decision to order modifications to the warnings about Addyi and alcohol, instead of removing the boxed warning and contraindication completely, is based on two sets of postmarket research studies.

In the FDA-required postmarketing trial in women who took Addyi and drank alcohol at the same time, there were missing or delayed measurements for blood pressure from when the women were first laying down to when they stood up that are critical in determining the risk of hypotension and syncope when taking Addyi and alcohol together. The FDA's specific concerns with the trial included:

• While there were no reports of syncope or hypotension needing intervention amongst women in the trial, the safety precautions built into this trial did not allow for an adequate assessment of this risk. For example, women with low blood pressure while lying down or with symptoms that could be related to low blood pressure (such as dizziness) were not permitted to stand up to have blood pressure measurements taken or had to have repeated blood pressure measurements while lying down until they were high enough for the women to safely stand up. As a result, the data collected had missing or delayed blood pressure measurements from these women while standing.
• Many more women had missing or delayed blood pressure measurements when they took Addyi and alcohol together compared to when they received alcohol alone or Addyi alone.
• The amount of missing blood pressure measurements peaked around the time when Addyi's blood levels were highest in those taking Addyi with alcohol.

The pattern of the missing or delayed measurements provides further evidence of an interaction between Addyi and alcohol that can increase the risk of hypotension and syncope. Given these results, the FDA has determined that the boxed warning and contraindication continue to be warranted. Women at home will not have the safety measures that were included in this trial or necessarily have access to immediate assistance if they were to experience severe hypotension or syncope, which can lead to serious outcomes including falls, accidents and bodily harm.

In other postmarketing trials, results showed that the risk of severe hypotension and syncope was reduced when women who consumed up to two alcoholic drinks waited at least two hours before taking Addyi. The FDA has found these results sufficient to support a modification to the boxed warning and contraindication stating that Addyi and alcohol must not be taken close in time (i.e. not within two hours).

Addyi is a serotonin 1A receptor agonist and a serotonin 2A receptor antagonist, but the mechanism by which the drug improves sexual desire and related distress is not known. Addyi is taken once daily. It is dosed at bedtime to help decrease the risk of adverse events occurring due to possible hypotension, syncope and central nervous system depression (such as sleepiness and sedation). Patients should discontinue treatment after eight weeks if they do not report an improvement in sexual desire and associated distress. The most common adverse reactions associated with the use of Addyi are dizziness, somnolence (sleepiness), nausea, fatigue, insomnia and dry mouth.

The Food and Drug Administration Amendments Act of 2007 gave the FDA the authority to require and, when necessary, order safety labeling changes to reflect new safety information about an approved prescription drug. Failure to respond to the order as outlined may result in monetary fines and additional enforcement actions including seizure of the product and injunction. Sprout has until April 16, 2019, to appeal the order through the FDA's formal dispute resolution process.