Clinical Trial Success Rates

Historical success rates for clinical trials by development phase, based on primary endpoint achievement data from our database.

PhaseTotal TrialsSuccessfulSuccess Rate
N/A552545.5%
Phase 116212.5%
Phase 1/Phase 218211.1%
Phase 21947337.6%
Phase 2/Phase 3201050%
Phase 328919366.8%
Phase 4241354.2%

Understanding Trial Success Rates

Clinical trial success rates vary dramatically by phase and therapeutic area. Industry-wide benchmarks from published research show approximately:

  • Phase 1 → Phase 2: ~65% success (primarily safety)
  • Phase 2 → Phase 3: ~30-35% (efficacy signal)
  • Phase 3 → Approval: ~55-60% (pivotal efficacy)
  • Overall (Phase 1 → Approval): ~10-12%

Oncology trials historically have lower success rates (~5% overall), while rare/orphan diseases often have higher rates due to unmet medical need and regulatory flexibility.

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