BOSTONTargeted anticancer drugs such as trastuzumab (Herceptin)
targeting HER-2 and imatinib mesylate (Gleevec) targeting Bcr-Abl represent the
potential of genome-based medicine, but the future may not be as close as it
seems, according to pharmaceutical executives who spoke at the 2001 Drug
Discovery Technology Conference.
They predicted an increase in the number of drugs to be tested as a result
of research into the human genome and a decrease in the time needed for the
early stages of drug development. Clinical trials take years, however, and
thousands of patients will be needed for some of the studies that are
envisioned. As large numbers of new targeted drugs reach the clinical trial
stage, it could create a medical logjam.
Klaus Lindpaintner, MD, MPH, vice president and head of genetics for Roche
Genetics, F. Hoffmann-La Roche AG, Basel, Switzerland, called clinical trials
an unavoidable "bottleneck" through which new drugs must pass.
"We need clinical data to get drugs approved. It’s the meat that we need
to put on that scaffold of the genome," he said.
Participating in a press briefing on the effect of genomics on
pharmaceutical research and development, Dr. Lindpaintner said that
"thousands of patients and thousands of controls" are essential for
complex studies that consider how genes, mutations, and environmental factors
affect illnesses and therapies.
"When it comes to clinical research, you can’t funnel patients
through quickly. They take time. There isn’t any magical shortcut," he
said. He called acquisition of sufficiently large patient cohorts for clinical
studies the major stumbling point in drug development today.
Importance of Markers
George M. Milne, Jr., PhD, senior vice president, Pfizer, Inc., Groton,
Connecticut, predicted that finding genomic markers to identify and monitor
patients will become increasingly important in clinical trials. He forecast
that early phases of future investigations would focus on using markers to
identify which patients might benefit from a therapy. "I think it will
have an increasing impact on the early definition of clinical efficacy and the
selection of doses, both of which are tremendous challenges in drug
development," he said.