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The Research Subject Advocate (RSA) Program
RSA HOME
A Guide to Data
and Safety Monitoring Boards (DSMB)
Reference:
Data Monitoring Committees in Clinical Trails; A Practical Perspective
By:
Susan S. Ellenberg, Thomas R. Fleming and David L. DeMets
Key
Points
- The
purpose of data monitoring committees (DMCs) is to protect the safety of
trial participants, the credibility of the study and the validity of study
results.
- DMCs
have a long history in trials sponsored by government agencies in the USA
and Europe.
- Pharmaceutical
companies are increasing their use of DMCs in trials of investigational
drugs, biologics and medical devices.
- Statistical
methods have been developed for interim monitoring of clinical trials.
- While
not all trails need DMCs, trials that address major health outcomes and are
designed to definitively address efficacy and safety issues should
incorporate DMC oversight.
Responsibilities
of the Data Monitoring Committee
- The
DMC may perform a variety of tasks in meeting its overall responsibilities
for safeguarding trail participants and trial integrity.
- These
tasks may address primarily scientific issues, such as an advisory review of
the study protocol, as well as primarily practical issues such as quality
assurance.
- Trials
may be considered for early termination based on proven efficacy,
unfavorable results ruling out benefit, safety concerns, or low probability
of achieving the trial objectives.
- All
trials monitored by a DMC should function under a charter, agreed to by the
trial sponsor and the committee members, that describes the structure and
operation of the committee.
Composition
of a Data Monitoring Committee
- DMCs
should be multidisciplinary, and should always include individuals with
relevant clinical and statistical expertise.
- Different
trials may require the inclusion of different disciplines on a DMC.
- The
appropriate size of a DMC depends on the type of trial and types of
expertise needed.
- The
study sponsor either appoints the DMC, or delegates this responsibility to
another group such as a steering committee.
- Training
programs for DMC service are needed.
Independence of the Data Monitoring
Committee: Avoiding Conflicts of Interest
- Individuals
with important conflicts of interest in regard to a particular clinical
trial should not serve on a DMC for that trail.
- The
most obvious conflicts are financial, but there can also be intellectual and
emotional conflicts of interest.
- Complete
elimination of all real, potential and perceived conflicts of interest is
generally not possible if one wishes to include DMC members who are
knowledgeable and experienced in the medical area being studied.
Confidentiality
Issues Relating to the Data Monitoring Committee
- Trial
integrity is best protected when interim data comparing treatment groups are
seen only by DMC members and the statistician preparing the interim reports.
- Separate
reports presenting aggregate data on administrative aspects of the trial can
be shared with the sponsor and trial leadership.
- In
limited circumstances there may be a strong rational for wider access to
comparative interim data.
- The
DMC should have access to fully unblinded data, with actual treatments and
not just codes available for its review.
Data
Monitoring Committee Meetings
- Standard
operating procedures for a DMC should be established.
- Early
in the trail, DMC review will focus more on safety, quality of conduct and
trail integrity than on efficacy evaluation..
- Interim
data reports submitted to the DMC should be as accurate and as up to date as
it is feasible to accomplish.
- DMC
meetings may include open and closed sessions, with trial leadership
permitted to attend open sessions and comparative interim data presented and
discussed only in closed sessions.
- Minutes
should be kept for all DMC sessions.
Data Monitoring Committee
Interactions with other Trail Components or Related Groups
- DMCs
will interact, occasionally or routinely, with other trial components, such
as the trial sponsor and the study chair.
- Different
models for such interaction have been developed, but problems can arise when
these other components are provided access to comparative interim data.
- An
independent statistician, separate from the primary (steering committee)
statistician for the trial, can be a useful addition to the trial structure
by preserving the ability of the trial statistician to participate in
unbiased interim decision-making with other members of the trial leadership.
- Sharing
of interim data between DMCs monitoring similar trials can be valuable but
needs to be done judiciously.
Statistical,
Philosophical and Ethical Issues in Data Monitoring
- Specialized
statistical methods are needed for monitoring clinical trials data to
differentiate between ‘evidence providing reliable conclusions’ and
‘fluctuations over calendar time that are consistent with random
variability’.
- Several
statistical approaches have been developed for evaluating and interpreting
data at interim time points during a clinical trial.
- Flexibility,
in terms of number and timing of interim analyses, can be built into the
statistical monitoring plan.
- DMCs
must be in agreement with trial sponsors and trail leadership regarding the
statistical and other criteria that will guide recommendations for early
termination of the trial.
Determining
When a Data Monitoring Committee is Needed
- All
trials need careful monitoring, but not all trials need independent DMcs.
- Independent
DMCs are most needed for randomized trials intended to provide definitive
data regarding treatments intended to save lives or prevent serious disease.
- Independent
DMCs are needed when interim analyses of safety and efficacy are considered
essential to ensure the safety of trail participants.
- ‘Internal”
DMCs may be valuable in some trails that do not need independent monitoring.
Regulatory
Considerations for the Operation of Data Monitoring Committees
- FDA
regulatins require ongoing safety monitoring of clinical trails, but DMCs
are only minimally addressed in government regulations.
- Despite
lack of requirements for DMCs, regulators generally expect randomized trials
with mortality or major morbidity endpoints to be monitored by an
independent DMC.
- FDA
reviewers generally do not participate in DMC meetings or serve on DMCs of
trials they regulate, and there are good reasons why they should not.
- The
FDA issued a draft guidance document on the establishment and operation of
DMCs in 2001.
Updated:
03/03/04