Celltrion Early Terminates and Voluntarily Withdraws Keytruda Biosimilar Phase 3 Trial in Europe, Highlighting Drug Development Uncertainty


  • Celltrion has voluntarily terminated the European Phase 3 clinical trial for CT-P51, a Keytruda biosimilar, and withdrawn the trial plan.
  • The trial targeted previously untreated patients with metastatic non-squamous non-small cell lung cancer. Due to changes in the global regulatory environment, EU countries were excluded from participating countries, prompting a strategic shift.
  • Patient enrollment has ended, and the trial will continue in non-EU countries to compare efficacy and safety against the original drug.
  • The statistical probability of a clinical trial drug receiving final approval is approximately 10%, urging investors to exercise caution.
  • [AI Summary]Celltrion's early termination and voluntary withdrawal of the European Phase 3 trial for Keytruda biosimilar CT-P51 reflects a strategic decision driven by regulatory changes, yet underscores the high uncertainty inherent in drug development. Investors should adopt a cautious approach given the low success rate of clinical trials.

KOSPI Filing Information


  • Major Management Matters Related To Investment Judgment (Early Termination Of European Phase 3 Clinical Trial Of CTP51 (Keytruda Biosimilar) And Voluntary Withdrawal Of Trial Plan)
  • Company: Celltrion (068270)
  • Submission: Celltrion, Inc.
  • Under KRX KOSPI Market Division

  • Shares: 232,553,706
  • Price: 175,200 KRW
  • Market Cap: 40,743.4 B KRW