Platform arm lifecycle and allocation

Track entry closure and assignment

Arm entry and closure change the available comparisons over time. Retain protocol versions and continue the required follow-up after recruitment closes.

Flow diagram

Steps

Define arm entry requirements

Record approvals, intervention evidence and master-protocol compatibility.

Open arm within an epoch

Version eligibility, comparator and allocation specifications.

Allocate among eligible active arms

Record randomization probabilities and eligible comparison sets.

Review continuation or closure

Apply prespecified efficacy, futility, safety or operational rules.

Retain follow-up after closure

Preserve arm history and analysis obligations when recruitment stops.

Continue recruitment

Maintain active-arm eligibility and allocation rules.

Modify under protocol

Apply only approved amendments and version the new epoch.

Close arm recruitment

Preserve outstanding follow-up and safety obligations.