OtherVerdict not stated
Most toxicology studies used a cis/trans isomer mixture (mix-ISA247) rather than the clinical product, with a limited bridging programme
Why: Bridging programme with voclosporin: 13-week rat study, rabbit embryo-fetal study and Ames test
“Voclosporin consists of 2 geometric isomers, a trans-isomer and a cis-isomer, and most studies in the programme have evaluated a mixture of the two isomers (mix-ISA247; 45-50% trans-, 50-55% cis-), whereas a few newer studies have evaluated the clinical product. A bridging programme with the two formulations has been performed which consisted of a 13-week oral voclosporin study in rats, an EFD study in rabbits and an Ames’ test.”
✓ VerifiedEMA assessment report, p. 25Source ↗ GenotoxicityAcceptedBeyond the letter
Genotoxicity battery run with the isomer mixture, underdosing the trans-isomer (about 55% of ICH-recommended doses)
Why: Weight of evidence supports lack of genotoxic potential; additional studies not necessary · Weight of evidence
“Note that the doses used in these studies assessed approximately 55% of the ICH recommended doses for the trans-isomer (for example if the Ames assay maximal dose is 5000 µg, only about 2500 µg, rather than 4500 µg of the trans-isomer (if voclosporin was assayed) would be assayed for this dose.”
✓ VerifiedFDA multi-discipline review, p. 67Source ↗ “While the level of trans-voclosporin might have been underdosed in the original genetic toxicity studies, the weight of evidence supports the lack of genotoxic potential and additional studies are not necessary.”
✓ VerifiedFDA multi-discipline review, p. 67Source ↗ Safety marginAcceptedBeyond the letter
NOAEL exposure margins in pivotal rat and monkey studies below the optimal 10x
Why: Toxicity profile similar to cyclosporine; substantial clinical experience with calcineurin inhibitors allows monitoring and risk minimisation · Class precedent · Human data
“Therefore, the safety margins are lower than the optimal 10x. However, the toxicological profile of voclosporin was similar to that of cyclosporine and the findings observed were either expected due to the pharmacological action of the drug (e.g., thymic medullary atrophy, absence of germinal centers, lymphomas) and/or to the known class specific adverse effects”
✓ VerifiedFDA multi-discipline review, p. 534Source ↗ “There is substantial clinical experience from the use of cyclosporine and other calcineurin inhibitors to allow for the proper monitoring of adverse findings and strategies to minimize risk (e.g., frequent dose adjustments).”
✓ VerifiedFDA multi-discipline review, p. 534Source ↗ Safety marginVerdict not stated
No exposure margin at the developmental NOAEL in the rabbit embryo-fetal study with mix-ISA247 (TK below quantification)
“At this dose, all TK values were BLQ why there are no margins to clinical exposure. Of note, the MoE to the dose associated with increased early and late resorptions is only 1.9.”
✓ VerifiedEMA assessment report, p. 31Source ↗