Soft Lock vs. Final Lock: Understanding the Two Critical Stages of Clinical Data Locking

 

Soft Lock

A soft lock occurs before Last Patient Last Visit (LPLV) while the study is still ongoing. Key characteristics:

  • Data are cleaned and source-verified for all visits up to a specified data cutoff date (or visit).
  • All external data and SAEs are reconciled.
  • All queries in scope must be answered and closed.
  • PI signatures are typically obtained.
  • Documentation is created and signed off by Data Management.
  • Data are extracted immediately after soft lock.
  • Changes may still occur after soft lock as additional data continue to come in.

Soft locks are often used for:

  • Interim analyses
  • NDA updates (e.g., 120-day safety update)
  • Topline readouts

Final Lock (Hard Lock)

The final lock occurs after the study is complete and all data are reviewed and declared final.

  • Triggered by LPLV.
  • No further changes are allowed after final lock.
  • Full database is clean, reconciled, and complete for final analysis and CSR.
  • Typically involves two full rounds of data review and reconciliation.

Final lock is required before:

  • Final CSR
  • Regulatory submission packages
  • Definitive deliverables



In Short

AspectSoft LockFinal Lock
Study statusOngoingComplete
Data completenessUp to a cutoff dateEntire study
Edits allowed?Yes (limited)No
PurposeInterim analyses, topline, submissions needing near-final dataCSR, regulatory finalization
PI Sign-offUsually requiredRequired
Data extractionAfter soft lockAfter final lock

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