AbbVie has received a Complete Response Letter from the U.S. Food and Drug Administration regarding its Biologics License Application for trenibotulinumtoxinE, known as TrenibotE, an investigational botulinum neurotoxin serotype E under review for the treatment of moderate to severe glabellar lines. According to AbbVie?s announcement, the agency?s feedback focused on manufacturing-process information and did not cite concerns related to clinical safety or efficacy. The company has said the letter did not request additional clinical trials and that it intends to submit a response in the coming months.

Most neuromodulators in clinical use today are based on botulinum toxin type A, the family behind the products patients recognize from more than two decades of cosmetic use. A serotype E toxin behaves differently. Published descriptions of TrenibotE characterize it as having a rapid onset, with effect reported as early as eight hours after administration, and a short duration of roughly two to three weeks.

That fast-onset, short-duration profile is distinct from the type A products that have defined the category.