DARTAcceptedBeyond the letter
No embryo-fetal development study for avutometinib or defactinib; weight-of-evidence assessment instead
Why: Weight-of-evidence assessment in lieu of EFD study; FDA agreed reproductive toxicology studies not warranted · Weight of evidence · Pharmacology or kinetics
“The Applicant provided a Weight of Evidence (WoE) assessment for avutometinib in lieu of an embryo fetal development study.”
✓ VerifiedFDA multi-discipline review, p. 106Source ↗ “The FDA agrees with the Applicant’s conclusions and that reproductive toxicology studies are not warranted to support this application.”
✓ VerifiedFDA multi-discipline review, p. 106Source ↗ DARTAccepted
No dedicated fertility studies; fertility assessed from reproductive organ findings in general toxicology studies
Why: Advanced cancer indication · Within the guideline · Serious disease
“Dedicated fertility studies have not been conducted with avutometinib, nor were warranted to support this marketing application in the proposed advanced cancer indication.”
✓ VerifiedFDA multi-discipline review, p. 36Source ↗ Safety pharmacologyCriticised but accepted
Defactinib rat neurobehavioral study inadequate and inconclusive; no additional CNS safety pharmacology study
Why: Detailed clinical observations in repeat-dose studies; stand-alone safety pharmacology not warranted per ICH S9 · Within the guideline
“Since the Applicant included detailed clinical observations in the repeat dose toxicology studies per ICH S9, and stand-alone safety pharmacology studies are not warranted per ICH S9, an additional CNS safety pharmacology study is not needed to support the proposed marketing application.”
✓ VerifiedFDA multi-discipline review, p. 48Source ↗ “The neurobehavioral study in rats was inadequate, and the results were considered inconclusive.”
✓ VerifiedFDA multi-discipline review, p. 48Source ↗ Safety marginAccepted with a conditionBeyond the letter
Avutometinib rat myocardial degeneration and necrosis at ≥0.01 mg/kg/day, below human exposure at recommended dose
Why: Cardiovascular findings were not observed in patients; findings added to label section 13.2 · Human data
“In the repeat-dose toxicology studies up to 13-weeks duration in rats, myocardial degeneration and necrosis were observed at doses ≥ 0.01 mg/kg/day (below the human exposure at the recommended dose based on AUC).”
✓ VerifiedFDA multi-discipline review, p. 35Source ↗ “The cardiovascular findings were added to section 13.2 of the label considering cardiovascular findings were not observed in patients.”
✓ VerifiedFDA multi-discipline review, p. 35Source ↗