In a small, multicenter patient study led by Marilyn J. Telen,
M.D., Wellcome Professor of Medicine in the division of hematology at
Duke University Medical School, patients who received an investigational
drug had quicker resolution of the pain episode, although the
difference compared to a control group did not rise to statistical
significance.
Telen said the study’s small size, as well as the wide variability
in the length of time that all of the study patients suffered painful
vascular obstruction, contributed to the statistical draw. A larger,
international study is planned to begin later this year to provide
greater clarity.
Patients who received the investigational drug also used far less
pain medication, which was self-administered. Those findings were
statistically significant.
The findings were reported online March 2, 2015, in the journal Blood.
“We have not had good therapies for people with this disease,”
Telen said. “But this approach shows more promise than anything else
I’ve seen in 34 years of treating sickle cell disease.”
Sickle cell anemia is a genetic condition in which some of the red
blood cells are stiff and shaped like crescents, or sickles, rather than
smooth and round. The abnormal blood cells can build up and block blood
flow to limbs and organs, causing severe pain and organ damage.
The National Heart, Lung, and Blood Institute estimates that up to
100,000 people in the United States, primarily African-Americans, have
the disease. The disease affects millions of people throughout the
world, and causes more than 75,000 hospitalizations a year in the United
States, which accounts for $1 billion in annual U.S. medical costs.
Telen said the current standard of care is pain control, typically
with opioids, and patients can be hospitalized for days or weeks.
Enrolling 76 patients from 17 sites in the United States, the study
randomly assigned patients to receive either a placebo or the
investigational drug, dubbed GMI-1070, or rivipansel. All patients also
received the standard treatment for pain and symptom management.
The drug is designed to prevent cells from sticking together and
thereby improve blood flow. For study participants who received the
investigational drug, the effects tended to begin within 24 hours, and
their painful crisis passed sooner than those receiving only treatment
for pain, but the statistical difference was not significant.
The researchers said the improvements seen in the amount of time to
resolution would likely be clinically meaningful if they were verified
in a larger trial.
Study authors also said the findings demonstrating lower use of pain medication among patients was a critical step forward.
“The difference in pain medication use was statistically
significant, and it occurred in the first 24 hours, which implies that
the therapy may be interfering with the mechanism of the
vaso-occlusion,” Telen said. “For these patients, having less pain is
very important.”
Telen said the larger study is planned to begin later this year, with a goal of enrolling more than 300 patients.
In addition to Telen, study authors include Ted Wun, Timothy L.
McCavit, Laura M. De Castro, Lakshmanan Krishnamurti, Sophie Lanzkron,
Lewis L. Hsu, Wally R. Smith, Seungshin Rhee, John L. Magnani, and Helen
Thackray.
The drug developer, GlycoMimetics, Inc., funded the study. Telen
has received consulting fees from the company. Full conflict disclosures
are provided in the publication.