CarcinogenicityAccepted with a conditionBeyond the letter
Vanzacaftor 2-year rat carcinogenicity study not completed before approval; deferred to postmarketing
Why: 2-year rat study to be conducted as a postmarketing requirement
“A 2-year carcinogenicity study in rats will be conducted as a postmarketing requirement (see Section 24).”
✓ VerifiedFDA integrated review, p. 97Source ↗ OtherAcceptedBeyond the letter
No full toxicology program for deutivacaftor; bridged to ivacaftor data via a 13-week rat comparison study
Why: No toxicologically significant differences between D-IVA and IVA at the same doses · Class precedent · Weight of evidence
“There were no toxicologically significant differences in findings between the same doses of D-IVA and IVA. Therefore, a bridge to the ivacaftor nonclinical program was justified and no further toxicology studies with D-IVA alone were recommended.”
✓ VerifiedFDA integrated review, p. 97Source ↗ DARTAcceptedBeyond the letter
No reproductive toxicity studies with deutivacaftor; ivacaftor data used instead
Why: Bridge to ivacaftor established in the 13-week rat toxicity study · Class precedent
“No reproductive toxicity studies have been conducted with D-IVA. A bridge between the toxicity profiles of D-IVA and IVA has been adequately established in the 13-week rat toxicity study.”
✓ VerifiedEMA assessment report, p. 52Source ↗ OtherAcceptedBeyond the letter
Tezacaftor tested only at one dose in the combination study; exposure multiple 1.2 (males) and 2.7 (females)
Why: Tezacaftor well studied and approved in a previous MAA · Class precedent
“TEZ was only assessed in combination studies with an exposure multiple of 1.2 for males and 2.7 for females at a dose where no toxicity was observed (only 1 dose tested). Since TEZ has been well studied and approved in a previous MAA, this limited amount of data is deemed acceptable.”
✓ VerifiedEMA assessment report, p. 54Source ↗ Juvenile toxQuestioned
Juvenile rat study (PND 7 to PND 70) too short to exclude liver toxicity with chronic treatment
“While the current juvenile study (PND 7–PND 70) did not identify the liver as a target organ, its limited duration raises uncertainty regarding potential effects with chronic treatment. Thus, the possibility of liver toxicity in juvenile animals cannot be completely ruled out.”
✓ VerifiedEMA assessment report, p. 62Source ↗