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Letybo
Published
Product name
Letybo
Active ingredient
LetibotulinumtoxinA
Submission type
New chemical entity
Decision
Approved
Decision date
Registration date
What this medicine was approved for
Letybo (letibotulinumtoxinA) was approved for the following therapeutic use:
Letybo is indicated for the temporary improvement in the appearance of moderate to severe glabellar frown lines in adults.
How this medicine works
LetibotulinumtoxinA blocks cholinergic transmission at the neuromuscular junction by inhibiting the release of acetylcholine from peripheral cholinergic nerve terminals. This inhibition occurs according to the following sequence:
- heavy chain of toxin binding to cholinergic nerve terminals
- internalisation of the toxin within vesicles into the nerve terminal
- translocation of the light-chain of the toxin molecule into the cytosol of the nerve terminal
- enzymatic cleavage of SNAP25, the presynaptic target protein essential for the release of acetylcholine.
Complete recovery of endplate function/impulse transmission after intramuscular injection normally occurs within three to four months as nerve terminals sprout and reconnect with the muscle endplate and the presynaptic neurotransmitter release mechanism becomes functional again.
Why the TGA approved or did not approve this medicine
The decision was based on quality (chemistry and manufacturing), nonclinical (pharmacology and toxicology), clinical (pharmacology, safety and efficacy) and risk management plan information submitted by the sponsor. The benefit-risk profile of Letybo was considered favourable for the therapeutic use approved.
Sponsor