Safety marginAcceptedBeyond the letter
No NOAEL in 26-week rat study: endocrine pancreas fibrosis, haemorrhage and pigment at all doses
Why: Spontaneous changes in aging rats exacerbated by BTK inhibitors, with no translation to other species · Class precedent · Pharmacology or kinetics
“Whereas a NOAEL was established at the highest tested dose level of 300 mg/kg/day in the 39-week dog study, no NOAEL was established in the 26-week rat study due to an increased incidence and severity of endocrine pancreas fibrosis, haemorrhage and pigment at all tested dose levels (i.e., doses of 30, 300, and 1000 mg/kg/day).”
✓ VerifiedEMA assessment report, p. 52Source ↗ “However, these changes are considered unlikely to translate to humans since they represent spontaneously occurring changes in aging rats, known to be exacerbated by BTK inhibitors with no translation to other species (Erickson et al 2017, Bhaskaran et al 2018).”
✓ VerifiedEMA assessment report, p. 52Source ↗ Juvenile toxAccepted with a conditionBeyond the letter
Ocular and neurobehavioral findings in juvenile rats; repeat juvenile toxicity study in older rats required postmarketing
Why: Juvenile rat results to be reviewed before the paediatric trial starts
“Given ocular and neurobehavioral findings in the completed juvenile toxicity study in rats, an additional PREA PMR will be issued for a repeat juvenile toxicity study in older rats that approximate children 6 years of age.”
✓ VerifiedFDA integrated review, p. 111Source ↗ “The results of the juvenile rat study will need to be submitted and reviewed prior to initiation of clinical study CLOU064F12302.”
✓ VerifiedFDA integrated review, p. 111Source ↗