MDR and MTH alerts can contain one of the following workflow states:

Workflow Status Description
Awaiting MDR Review The alert is queued for analyst review.
Note: MTH alerts are only visible after an analyst determines them to be a likely threat. Visible MTH alerts rarely have an Awaiting MDR Review workflow state.
In progress Analyst is actively triaging the alert.
Triage complete Analyst completed triage of the alert and a determination is made.
Pending MDR response Analyst is in the process of responding to your comment.
Received MDR response Analyst responded to your comment or question left on the alert.