Complete Response Letter NDA 505b1 220049 (Aug 18, 2025)

Summary

The FDA has issued a Complete Response Letter (CRL) for NDA 220049 for vatiquinone, indicating that the application is not ready for approval in its current form. The agency found that the nominally significant findings on exploratory endpoints (Upright Stability Subscale and Modified Fatigue Impact Scale) were not statistically robust or persuasive enough to establish effectiveness, especially given negative results on primary and key secondary endpoints. Concerns were raised regarding statistical observations, handling of missing data, baseline imbalances, and the interpretability of certain outcome assessments. Real-world evidence and biomarker data submitted as confirmatory evidence were deemed insufficient to serve as such without a positive, adequate, and well-controlled study. The FDA requires a new positive, adequate, and well-controlled study to establish effectiveness, suggests a specific study design, and outlines deficiencies related to nonclinical/product quality, labeling, proprietary name, and a comprehensive safety update for any resubmission.

Key points

• Conduct a positive, adequate, and well-controlled study to establish the effectiveness of vatiquinone in the treatment of subjects with Friedreich's Ataxia (FA).
• Consider conducting a prospective randomized, controlled study in pediatric subjects with FA with change from baseline in Upright Stability Subscale (USS) as a primary endpoint.
• Conduct adequate studies to qualify the multiple drug substance and drug product impurities identified.
• Resubmit the proposed proprietary name when all application deficiencies have been addressed.
• Include a safety update as described at 21 CFR 314.50(d)(5)(vi)(b) in any resubmission.
• The safety update must describe in detail any significant changes or findings in the safety profile.
• The safety update must present new safety data from studies/clinical trials for the proposed indication using the same format as in the original submission.
• The safety update must present tabulations of new safety data combined with original application data.

Cited reasons

• Insufficient Evidence of Effectiveness from Clinical Trials
• Unqualified Drug Substance and Drug Product Impurities
• Proprietary Name Resubmission Required
• Comprehensive Safety Update Required
• Refine Population Pharmacokinetics (PK) Model
• The application for vatiquinone received a Complete Response Letter primarily due to insufficient evidence of effectiveness from clinical trials, unresolved product quality issues related to impurities, and administrative requirements for resubmission including a comprehensive safety update and proprietary name resubmission. The agency requires a new adequate and well-controlled study to establish effectiveness.

Recommended actions

• Conduct a positive, adequate, and well-controlled study to establish the effectiveness of vatiquinone in the treatment of subjects with Friedreich's Ataxia (FA).
• Consider conducting a prospective randomized, controlled study in pediatric subjects with FA with change from baseline in Upright Stability Subscale (USS) as a primary endpoint.
• Conduct adequate studies to qualify the multiple drug substance and drug product impurities identified.
• Resubmit the proposed proprietary name when all application deficiencies have been addressed.
• Include a safety update as described at 21 CFR 314.50(d)(5)(vi)(b) in any resubmission.
• The safety update must describe in detail any significant changes or findings in the safety profile.
• The safety update must present new safety data from studies/clinical trials for the proposed indication using the same format as in the original submission.
• The safety update must present tabulations of new safety data combined with original application data.

Deficiency summary

The application for vatiquinone received a Complete Response Letter primarily due to insufficient evidence of effectiveness from clinical trials, unresolved product quality issues related to impurities, and administrative requirements for resubmission including a comprehensive safety update and proprietary name resubmission. The agency requires a new adequate and well-controlled study to establish effectiveness.

Findings

Regulatory context

Submission stage

final decision

Regulatory pathway

NDA

Impact

Impact score

0.95

Estimated delay

730 days

Estimated rework cost

$0

Subsequent action

resubmission

Strategic insights

The primary theme is the lack of substantial evidence of effectiveness, necessitating a new pivotal clinical trial. Secondary themes include unresolved product quality issues related to impurities and standard administrative requirements for resubmission, including a detailed safety update.

Regulatory change impact: Pending sponsor mitigation plan

Approval likelihood after response: 5%