OtherAcceptedBeyond the letter
No new nonclinical program for drospirenone; relies on FDA's previous findings of safety for the listed drug YAZ
Why: Adequate scientific bridge to the listed drug YAZ established · Class precedent
“The Applicant refers to the Agency’s previous findings of safety for the nonclinical pharmacology, pharmacokinetics, and toxicology of the DRSP component of the approved product YAZ® (NDA 021676, approved March 16, 2006) to support the nonclinical safety of drospirenone in Nextstellis.”
✓ VerifiedFDA multi-discipline review, p. 16Source ↗ “An adequate scientific bridge has been established to the Listed Drug YAZ®; therefore, the Applicant may rely on the nonclinical sections of the YAZ approved labeling to support Nextstellis labeling.”
✓ VerifiedFDA multi-discipline review, p. 16Source ↗ GenotoxicityAcceptedBeyond the letter
Estetrol positive in Ames strain TA102; in vivo assays did not suggest genotoxicity
Why: In vivo studies do not suggest that E4 is a genotoxicant · Weight of evidence
“The genotoxicity testing of E4 was not straight-forward. In the first Ames test, E4 was positive, as increased revertants were seen in the TA102 strain.”
✓ VerifiedEMA assessment report, p. 31Source ↗ “Collectively, the in vivo studies do not suggest that E4 is a genotoxicant.”
✓ VerifiedEMA assessment report, p. 32Source ↗ Safety marginCriticised but acceptedBeyond the letter
Low toxicity margins for estetrol and drospirenone in the repeat-dose program
Why: Toxicities identified are clinically well known from other combined oral contraceptives · Class precedent · Human data
“Margins of toxicity are considered to be low, but they are acceptable, considering that the toxicities identified in the programme are clinically well-known from other COC products.”
✓ VerifiedEMA assessment report, p. 36Source ↗ Impurity or metaboliteAcceptedBeyond the letter
Estetrol metabolism not studied in monkey; no animal plasma data on the two major human glucuronide metabolites
Why: Glucuronides have low pharmacological activity and form via direct conjugation; no toxicological concern · Pharmacology or kinetics
“In vivo metabolic pathways have not been studied in monkeys. No data on the levels of the two major human metabolites in plasma, the E4-3- and E4-16-glucuronide, is thus available.”
✓ VerifiedEMA assessment report, p. 27Source ↗ “Since the two glucuronides have low pharmacological activity and glucuronidation and sulfation seem to be formed via direct reactions they are considered to be of no toxicological concern.”
✓ VerifiedEMA assessment report, p. 27Source ↗