The Food & Drug Administration (FDA) has delayed a decision on the approval of  Botox as a treatment for upper limb spasticity in stroke victims.  The agency is seeking more information from Botox maker, Allergan.

According to Reuters, the FDA wants to review  Allergan’s proposed Risk Evaluation and Mitigation Strategy [REMS]  plan for Botox  before making a decision on its application for expanding its use.  The agency is also seeking additional documentation and analysis of a clinical study included in the approval application. Finally, the FDA has also proposed certain label revisions, including one that could broaden Botox use to upper limb spasticity regardless of underlying cause, Reuters said.

The FDA is not requiring  that Allergan conduct additional clinical trials for the new use of Botox , something that could have delayed the agency’s decision by years, Reuters said.  The company told Reuters that it could comply with the FDA’s request within 60 to 90 days.

Allergan markets two Botox products.  Botox Cosmetic is made from botulinum toxin type A, and is approved for temporary improvement in the appearance of moderate to severe facial frown lines.  It is different from Botox, another Allergan botulinum toxin product, which is approved to treat conditions such as blepharospasm (spasm of the eyelids), cervical dystonia (severe neck muscle spasms), and severe primary axillary hyperhydrosis (excess sweating).

Late last month, the FDA announced that all botulinum toxin injection products, including Botox and Botox Cosmetic, would carry a Black Box warning regarding the risk of adverse events when the effects of a botulinum toxin injection spreads beyond the site where it was injected. In addition to the new warning, the agency is also requiring the makers of these drugs to develop and implement a REMS to provide more information regarding the risk for distant spread of botulinum toxin effects after local injection, as well as information to explain that botulinum toxin products cannot be interchanged. The REMS would also include a Medication Guide that explains the risks to patients, their families, and caregivers.

Last February, the FDA launched a safety review of botulinum toxin injections, including Botox and Botox Cosmetic. The FDA said at the time that it had received reports of adverse reactions that resembled botulism infections in patients receiving the injections. The most serious cases had outcomes that included hospitalization and death, and occurred mostly in children treated off-label for cerebral palsy-associated limb spasticity. The FDA said that the adverse reactions may have been due to overdosing.