Impurity or metaboliteCriticised but acceptedBeyond the letter
No toxicokinetics of major human metabolite M34.5 in pivotal rat studies; exposure only extrapolated from single-dose ADME data
Why: Extrapolated exposure margin with uncertainty factor suggests M34.5 likely qualified · Pharmacology or kinetics
“No TK assessments of M34.5 have been performed in any of the pivotal safety studies (including carcinogenicity and reproductive toxicity studies) conducted in the rat.”
✓ VerifiedEMA assessment report, p. 21Source ↗ “As the human exposure of M34.5 after repeat dosing of osilodrostat is only estimated in an uncertain simulation model, the addition of an uncertainty factor of 10 was used, resulting in exposure margin of 1.3 in the high osilodrostat dose (30 mg/kg/day) used in the 2-year rat cancer study. Thus, based on these extrapolations M34.5 has likely been toxicologically qualified.”
✓ VerifiedEMA assessment report, p. 26Source ↗ SpeciesAcceptedBeyond the letter
Toxicity from cortisol inhibition could not be studied: in rats and monkeys osilodrostat mainly inhibits aldosterone synthase
Why: Adverse effects of hypocortisolism are clinically well known · Human data · No relevant species
“Since no inhibition on PCC (plasma corticosterone concentration) in rats and monkeys not infused with ACTH is seen, toxicity associated with cortisol inhibition cannot be studied.”
✓ VerifiedEMA assessment report, p. 21Source ↗ “However, the adverse effects of hypocortisolism are clinically well known (e.g. nausea, vomiting, fatigue, abdominal pain, dizziness).”
✓ VerifiedEMA assessment report, p. 21Source ↗