Objectives: To quantify the amount of botulinum toxin-A (BoNT-A) protein in each vial of commercial BoNT-A product and compare the light chain activity of 150 kDa BoNT-A in different products.
Introduction: BoNT-A effects are mediated by the 150 kDa BoNT-A neurotoxin. Each product available has a unique manufacturing process, different excipients and noninterchangeable potency units. For example, in glabellar lines, total doses are abobotulinumtoxinA (AboBoNT-A) 50U, onabotulinumtoxinA (OnaBoNT-A) 20U, and incobotulinumtoxinA (IncoBoNT-A) 20U. Light chain activity of 150 kDa BoNT-A in different products is unknown.
Materials / method: We used sandwich ELISA with antibodies specific to 150 kDa BoNT-A to quantify the amount (pg) of 150 kDa BoNT-A in each product; each of the commercial products were quantitated versus a calibration curve of recombinant, pure BoNT-A. Light chain activity was assessed using EndoPep assay, where the concentration of the cleaved target was measured and quantity of 150 kDa BoNT-A determined relative to quantity of recombinant BoNT-A required for equivalent light chain activity.
Results: The amount of neurotoxin per product unit was: AboBoNT-A (5.38pg), OnaBoNT-A (9.04pg) and IncoBoNT-A (4.03pg). There were no significant differences between BoNT products in light-chain activity. Thus, when total recommended doses for glabellar lines are injected, there is more neurotoxin injected in AboBoNT-A (50U x 5.38pg = 0.269ng) than in OnaBoNT-A (20U x 9.04pg = 0.181ng) and IncoBoNT-A (20U x 4.03 = 0.081ng).
Conclusion: No differences in light chain activity were seen between BoNT-A products. However, there were greater amounts of neurotoxin in AboBoNT-A at the recommended dose for glabellar lines than either OnaBoNT-A or IncoBoNT-A. At the recommended dose, all BoNT-A products have a similar safety profile. At approved doses, the amount of active neurotoxin in AboBoNT-A is likely to be a major factor to explain the long-lasting symptomatic relief observed in clinical studies within a well-characterised safety and tolerability profile.
Disclosures
Did you receive any funding to support your research for this TOPIC?
Yes
Please specify entities (individual, company, society): Ipsen
Were you provided with any honoraria, payment or other compensation for your work on this study?
Yes
Please specify entities (individual, company, society): Ipsen
Do you have any financial relationship with any entity which may closely compete with the medications, materials or instruments covered by your study?
Yes
Please specify entities (individual, company, society): Employed by Ipsen
Do you own or have you applied for any patents in conjunction with the instruments, medications or materials discussed in your study?
No
This work is presented thanks to the support of: Ipsen