Without the option of recommending physician certification as a condition for flibanserin approval, the Food and Drug Administration advisory panel vote might have shifted against approval of the drug for treating hypoactive sexual desire disorder in premenopausal women.
At a joint meeting of two FDA advisory panels in June, members of the Bone, Reproductive and Urologic Drugs Advisory Committee and the Drug Safety and Risk Management Advisory Committee voted 18-6 that the overall benefit-risk profile of flibanserin supported approval for treating hypoactive sexual desire disorder (HSDD) in premenopausal women, provided that certain risk management options beyond labeling were implemented. If approved by the FDA, flibanserin would be the first drug approved for treating HSDD.
Assurance that prescribers would be fully apprised of the serious risks of hypotension and syncope associated with the drug, exacerbation of those side effects when combined with alcohol or a CYP3A4 inhibitor – and the modest effects over placebo – was cited by several of the panelists who voted in favor of approval.
All of those voting in favor of approval chose the option of supporting approval “only if certain risk management options beyond labeling are implemented.” None of the panelists voted for the option of supporting approval with “labeling alone to manage the risks.”
The conditions include a risk management plan to address serious adverse effects associated with the drug, a requirement for physician certification, and postmarketing studies to further evaluate and monitor the drug’s safety and efficacy.
The risks of hypotension and syncope, and central nervous system depression are also exacerbated by moderate or strong CYP3A4 inhibitors, but the interaction with alcohol was raised as a particularly serious issue because of the high rate of alcohol use and binge drinking among women who would likely be treated with flibanserin, according to FDA reviewers.
The risk of drug interactions can be mitigated with drug interaction screening programs used in health care systems, such as in electronic medical records and pharmacies, while alcohol use is a patient-dependent behavior, is common among women, and therefore more difficult to control, Kimberly Lehrfeld, Pharm.D., a team leader in the division of risk management in the FDA’s office of medication error prevention and analysis, said at the meeting. Several panelists recommended that alcohol use be a contraindication.
Physician certification is among the Elements to Assure Safe Use or ETASU, which along with a medication guide and a communication plan for health care providers, are components of a Risk Evaluation and Mitigation Strategy ( REMS ), a way to help manage the risks of a drug or biologic while still making it available to patients who need it.
Physician certification is part of the REMS for drugs such as mifepristone (Mifeprex), thalidomide (Thalomid), and natalizumab (Tysabri).
“A risk strategy that gets physicians the information they need to use it properly is going to be key,” said Dr. Robert Silbergleit, who voted for approval.”A REMS strategy is going to be very important because I think that the most likely risks … are going to come from physicians who don’t use the drug properly because they’re not properly educated.”
Dr. Silbergleit, a professor in the department of emergency medicine at the University of Michigan, Ann Arbor, said he was also concerned about the marketing of the drug. “Clinicians may be in the situation where they have to counter direct-to-consumer marketing that could lead to misuse of the drug,” he said at the meeting.
Also voting for approval, Marjorie Shaw Phillips, R.Ph., pharmacy coordinator at Georgia Regents Medical Center in Augusta, said that everyone needs to be aware of the potential safety concerns. But while she does not think pharmacy registration would be beneficial, there is a role for the pharmacist to confirm that it’s an educated provider prescribing the drug and that they’ve discussed the risks with the patient.
She added that it will be important for physicians to set realistic expectations for patients.
“It’s not a magical little pink pill, and there are going to be a whole lot of women with sexual dysfunction for whom there’s no evidence that it’s going to benefit them,” she said at the meeting.
The panel did not specifically recommend pharmacy certification, but pharmacists would have to verify that the prescribing physicians are certified, if the drug is approved, an FDA official said at the meeting.
A decision from the FDA is expected in August. The FDA panelists reported having no relevant financial disclosures.
Sprout Pharmaceuticals, flibanserin’s manufacturer, said in a statement that the company looks forward “to continuing our work with the FDA as it completes its review of our new drug application, including the discussion of a Risks Evaluation and Mitigation Strategy.” If approved, the company plans to market flibanserin as “Addyi.”
