LanbotulinumtoxinA (LAN) is manufactured and registered in China since 1994. Despite its widespread use in China and its increasing use in other Asian countries and in South America, it is not yet well known elsewhere. We wanted to compare its potency labelling using the mouse diaphragm assay (MDA), an isolated muscle model for botulinum toxin (BT) potency measurements, which is superior to clinical tests and which was recently refined as an alternative batch release assay for BT manufacturing. We also wanted to estimate LAN manufacturing quality by testing its inter-batch potency consistency. Potencies of 20, 60 and 100 MU of LAN, onabotulinumtoxinA (ONA) and incobotulinumtoxinA (INCO) were measured by the inversely related paresis time (PT) in the MDA. The PT (M ± SD) of all doses of LAN, ONA and INCO was 90.4 ± 27.0 min, 114.9 ± 46.5 min and 94.3 ± 29.9 min, respectively. Statistical analysis demonstrated indistinguishable potency labelling of LAN and INCO, but revealed a slightly lower potency of ONA compared to LAN and INCO. PT of LAN batch 1 and LAN batch 2 was 86.9 ± 21.2 min and 94.0 ± 32.8 min, respectively (no statistically significant difference), suggesting an adequate LAN manufacturing consistency. The MDA is an appropriate instrument for potency testing of BT drugs, including new ones currently under development. Our results allow comparing therapeutic effects, adverse effects and economics of LAN, ONA and INCO. They also suggest adequate manufacturing consistency of LAN.
Keywords: Conversion factors; Drug comparability; Hemidiaphragm assay; IncobotulinumtoxinA; LanbotulinumtoxinA; Manufacturing consistency; OnabotulinumtoxinA; Potency labelling.