From FDA.gov A fundamental responsibility of a

From FDA.gov

A fundamental responsibility of a DMC is to make recommendations to the
sponsor (and/or, as noted in the Introduction, a steering committee or other
group delegated by the sponsor to make decisions about the trial) concerning
the continuation of the study. Most frequently, a DMC’s recommendation
after an interim review is for the study to continue as designed. Other
recommendations that might be made include study termination, study
continuation with major or minor modifications, or temporary suspension of
enrollment and/or study intervention until some uncertainty is resolved.
Because a DMC’s actions potentially impact the safety of trial participants, it
is important that a DMC express its recommendations very clearly to the
sponsor. Both a written recommendation and oral communication, with
opportunity for questions and discussion, can be valuable. Recommendations
for modifications are best accompanied by the minimum amount of data
required for the sponsor to make a reasoned decision about the
recommendation, and the rationale for such recommendations should be as
clear and precise as possible. Sponsors may wish to develop internal
procedures to limit the interim data released by a DMC after a
recommendation until a decision is made regarding acceptance or rejection of
the recommendation, to facilitate maintaining confidentiality of the interim
results should the trial continue. We recommend that a DMC document its
recommendations, and the rationale for such recommendations, in a form that
can be reviewed by the sponsor and then circulated, if and as appropriate, to
IRBs, FDA, and/or other interested parties. Sections 5 and 7.2.1 address
implications for reporting to FDA of DMC recommendations for major study
changes such as early study termination.