Monday, March 30, 2009

Design of clinical trials

There used to be four primary pediatric cancer research groups in North America:
Children’s Cancer Group (CCG), Pediatric Oncology Group (POG), National Wilms’
Tumor Study Group (NWTSG), and Intergroup Rhabdomyosarcoma Study Group
(IRSG). In July 1998, the four groups decided to form a single pediatric cancer clinical
trials organization. The groups officially merged in 2000 under the new name, Chil-
dren’s Oncology Group (COG). New trials developed for children with cancer will be
offered under the COG name. Trials begun by the previous research groups will
continue until they are completed as planned.
Children’s Oncology Group
440 East Huntington Drive #300
Arcadia, CA 91006
(626) 447-0064
(800) 458-6223 (US and Canada)
http://www.childrensoncologygroup.org
More than 230 institutions that treat children with cancer are members of COG.
Researchers from each institution contribute to the design of new clinical trials for
children with cancer. The National Cancer Institute and some individual institutions
design their own trials for children treated at those institutions.
Supervision of clinical trials
The ethical and legal codes ruling medical practice also apply to clinical trials. In
addition, most research is federally funded or regulated (all COG trials are), with
rules to protect patients. COG also has review boards that meet at prearranged dates
for the duration of a clinical trial to ensure that the risks of all parts of the trial are
acceptable relative to the benefits.
Side effects are reported by the treating institution. If concerns are raised, the study
may be temporarily halted while an independent Data Safety and Monitoring Board
(DSMB) and the study committee review the situation. If one arm of the trial is causing
unexpected or unacceptable side effects, that portion is stopped, and the children
enrolled are given the better treatment. If one of the arms appears to be less effective
than the standard, it will be terminated. Conversely, if one arm is better than the
standard, the trial will also be terminated.
When Brian first entered the CCG-1922 protocol, there were four
arms. One was to see which had the best response in treatments between
prednisone versus decadron and 6MP versus 6TG. After Brian completed
this protocol, in December 1996, we were told that the patients that were
on 6MP and prednisone were to be switched to 6MP and decadron. There
seemed to be a better outcome.
The results of the CCG-1922 study are not complete. But we were told
in the beginning of the protocol that if one arm was doing better than the
other arm, the patients would be switched to the better arm.
All institutions that conduct clinical trials also have an Institutional Review Board
(IRB) or an ethics committee that reviews and approves all research taking place
there. The purpose of such boards and committees—made up of scientists, doctors,
nurses, and citizens from the community—is to protect patients. Before a child is
enrolled on a COG trial, the trial must be reviewed and approved by the NCI and
COG. In addition, the IRB at the hospital where the child is being treated must also
approve the trial.