A UC Davis clinical trial has found safe a drug designed to treat a common, painful complication of sickle cell disease.
There are currently no specific treatments for vaso-occlusive crises, during which clumped-together blood cells hinder blood flow. It is responsible for more than 70,000 hospitalizations annually, according to Ted Wun, associate dean for research at the UCD School of Medicine.
The 15-patient trial found no severe side-effects from the drug, dubbed GMI 1070, and that it was maintaining adequate concentrations in the blood.
Published online in the journal Public Library of Science ONE, the study was not aimed at determining the drug’s effectiveness, but Wun said it did show small improvements in blood flow and reduced the markers of cell activation.
Sickle cell disease, which lowers life expectancy by 20 to 30 years, affects an estimated 90,000 to 100,000 Americans, mostly blacks, according to the U.S. Centers for Disease Control and Prevention.
It is caused by abnormal hemoglobin that contorts red blood cells into a sickle shape, making them stiff and sticky. These clumped cells reduce blood flow, leading to severe hip, back and long-bone pain, and, often, chest and abdominal pain.
“White blood cells bind to inflamed blood vessel walls and sickle red cells stick to white cells, but interestingly the initiating event is the white cells,” Wun said in a news release. “If we could interrupt that white cell interaction, we could stop the cycle that leads to vaso-occlusions.”
The new drug is designed to do that by mimicking sugars attached to cell-adhesion proteins, called selectins, reducing the stickiness and increasing blood flow.
Sickle cell most often strikes the kidneys, lungs and spleen, but it can affect any organ. Stroke, infections, hypertension and heart failure are among its severe complications.
Patients in the trial tolerated the drug well, with headaches the most common side-effect. Preliminary results of a second trial also have been positive, and have been submitted for publication, according to researchers. A third phase is planned.
“If the phase III study confirms that GMI 1070 is effective, it would be a huge advance for the sickle cell community,” Wun said.
GlycoMimetics Inc., a Maryland-based biotechnology company based in Gaithersburg, produces the new drug under the trade name Rivipansel. The company paid for the trial.
Also this week, National Institutes of Health scientists announced the results of a study that found bone marrow transplants can reverse sickle cell disease. The transplant worked in 26 of 30 adults, and 15 of them were even able to stop taking drugs that prevent rejection one year later.
The treatment is a modified version of bone marrow transplants that have worked in children. Donors are a brother or sister whose stem cell-rich bone marrow is a good match for the patient.
The treatment involves using chemotherapy and radiation to destroy bone marrow before replacing it with healthy donor marrow cells.
Results from the adult study, involving patients aged 29 on average, were published in the Journal of the American Medical Association.
—The Associated Press contributed to this report.