If studies showed it was 10% more effective than palivizumab in reducing hospitalizations, then the risks of non–life-threatening skin reactions and rare cases of more severe anaphylaxis “might be acceptable risks in this high-risk population who comes in and not infrequently expires from RSV,” he added.
Since approval, an estimated 1.2 million people have received palivizumab and 10 cases of anaphylaxis have been reported to the FDA's voluntary adverse event reporting program, according to the FDA. A warning about the potential for anaphylaxis is on the palivizumab label.
If motavizumab is approved, MedImmune plans to market the drug as Rezield, with a risk management plan that would include educating prescribers about how to manage skin reactions, enhanced vigilance of adverse events, and postmarketing studies that would address issues that include evaluating the rates and severity of hypersensitivity reactions associated with motavizumab, the emergence of motavizumab-resistant RSV, and adverse event rates in the real-world setting.
The FDA is expected to make a decision on motavizumab by June 24. MedImmune has not filed for approval elsewhere, but plans to file for approval in the European Union, according to a company spokesperson. Members of FDA advisory panels have been cleared of potential conflicts of interest by the FDA prior to the meeting, but the FDA occasionally grants a waiver to a panelist with a conflict of interest.