Conference Coverage

SelG1 cut pain crises in sickle cell disease



The humanized antibody SelG1 decreased the frequency of acute pain episodes in people with sickle cell disease, based on results from the multinational, randomized, double-blind, placebo-controlled SUSTAIN study that will be presented at the annual meeting of the American Society of Hematology in San Diego.

In other sickle cell disease research to be presented at the meeting, researchers will be presenting new findings from two studies conducted in Africa. One study examines a team approach to reduce mortality in pregnant women with sickle cell disease in Ghana. The other study, called SPIN, is a safety and feasibility study conducted in advance of a randomized trial in Nigerian children at risk for stroke.

CDC/Janice Haney Carr
In the study of SelG1, a first-in-class humanized anti–P-selectin antibody, a research team led by Kenneth Ataga, MD, of the University of North Carolina at Chapel Hill, recruited 198 patients aged 16-65 years with sickle cell disease. The patients were randomized to one of three groups: a 3 mg/kg dose of SelG1, a 5 mg/kg dose of SelG1, or placebo.

After 1 year, the annual rate of sickle cell–related pain crises resulting in a visit to a medical facility was 1.6 in the group receiving the 5 mg/kg dose, compared with 3 in the placebo group. The 47% difference was statistically significant (P = .01).

Also, time to first pain crisis was a median of 4 months in those who received the 5 mg/kg dose and 1.4 months for those in the placebo group (P = .001).

Infections were not seen increased in either of the groups randomized to SelG1, and no treatment-related deaths occurred during the course of the study. The first-in-class agent “appears to be safe and well tolerated,” as well as effective in reducing pain episodes, Dr. Ataga and his colleagues wrote in their abstract.

In the Nigerian trial, led by Najibah Aliyu Galadanci, MD, MPH, of Bayero University in Kano, Nigeria, the goal was to determine whether families of children with sickle cell disease and transcranial Doppler measurements indicative of increased risk for stroke could be recruited and retained in a large clinical trial, and whether they could adhere to the medication regimen. The trial also obtained preliminary evidence for hydroxyurea’s safety in this clinical setting, where transfusion therapy is not an option for most children.

Dr. Galadanci and her colleagues approached 375 families for transcranial Doppler screening, and 90% accepted. Among families of children found to have elevated measures of risk on transcranial Doppler, 92% participated in the study and received a moderate dose of hydroxyurea (20 mg/kg) for 2 years. A comparison group included 210 children without elevated measures on transcranial Doppler. These children underwent regular monitoring but were not offered medication unless transcranial Doppler measures were found to be elevated.

Study adherence was exceptionally high: the families missed no monthly research visits, and no participants in the active treatment group dropped out voluntarily.

Also, at 2 years, the children treated with hydroxyurea did not have evidence of excessive toxicity, compared with the children who did not receive the drug. “Our results provide strong preliminary evidence supporting the current multicenter randomized controlled trial comparing hydroxyurea therapy (20 mg/kg per day vs. 10 mg/kg per day) for preventing primary strokes in children with sickle cell anemia living in Nigeria,” Dr. Galadanci and her colleagues wrote in their abstract.

In the third study, a multidisciplinary team decreased mortality in pregnant women who had sickle cell disease and lived in low and middle income settings, according to Eugenia Vicky Naa Kwarley Asare, MD, of the Ghana Institute of Clinical Genetics and the Korle-Bu Teaching Hospital in Accra.

In a prospective trial in Ghana, where maternal mortality among women with sickle cell disease is estimated to be 8,300 per 100,000 live births, compared with 690 for women without sickle cell disease, Dr. Asare and her colleagues’ multidisciplinary team included obstetricians, hematologists, pulmonologists, and nurses, and the planned intervention protocols included a number of changes to make management more consistent and intensive. A total of 154 pregnancies were evaluated before the intervention, and 91 after. Median gestational age was 24 weeks at enrollment, and median maternal age was 29 years for both pre- and post-intervention cohorts.

Maternal mortality before the intervention was 9.7% (15 of 154) and after the intervention was 1.1% (1 of 91) of total deliveries.

Dr. Ataga’s study was sponsored by Selexys Pharmaceuticals, the drug’s manufacturer, and included coinvestigators who are employees of Selexys Pharmaceuticals or who disclosed relationships with other drug manufacturers. Dr. Galadanci’s and Dr. Asare’s groups disclosed no conflicts of interest.

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