HONOLULU – (ICH), according to trial results described at the International Stroke Conference sponsored by the American Heart Association. However, the drug is safe and well tolerated and data suggest that it may improve outcomes at 180 days.
Animal studies indicate that iron, which is released from hemolyzed red blood cells, accumulates in the brain after ICH and is associated with secondary neuronal injury and death. Researchers have found that deferoxamine, an iron chelator, provides neuroprotection and improves recovery after experimental ICH. The drug also has anti-inflammatory, antiapoptotic, and BP-lowering effects. Deferoxamine has been approved since the 1960s.
Magdy H. Selim, MD, PhD, a neurologist at Beth Israel Deaconess Medical Center in Boston, and colleagues hypothesized that treatment with deferoxamine could improve outcomes in patients with ICH. The researchers conducted a phase 2 clinical trial to evaluate whether deferoxamine should be studied in a phase 3 efficacy trial. In their multicenter, double-blind study, Dr. Selim and his colleagues randomized patients with spontaneous supratentorial ICH in equal groups to 32 mg/kg per day of deferoxamine or saline placebo. Treatments were administered as intravenous infusions for 3 consecutive days, and therapy was initiated within 24 hours after ICH onset. The follow-up period was 6 months.
Eligible participants had an National Institutes of Health Stroke Scale score of 6 or higher, a Glasgow Coma Scale score greater than 6, and had been functionally independent before the hemorrhage. The researchers excluded patients with a secondary cause for ICH or coagulopathy.
The primary endpoint in the futility analysis was the proportion of participants with a good clinical outcome – defined as a modified Rankin Scale (mRS) score of 0-2 – at 90 days and 180 days. The secondary endpoint was good outcome, defined as an mRS score of 0-3, at 90 days. Safety endpoints included all deferoxamine-related adverse events until day 7 or discharge (whichever was earlier) and serious adverse events through day 90.
Dr. Selim and his colleagues enrolled 294 participants in their trial, 3 of whom did not receive treatment. Of these included participants, 147 (50.5%) were randomized to placebo and 144 (49.5%) were randomized to deferoxamine. Participants’ mean age was 60.3 years, and 38.5% of the population was female.
Overall, the two study arms did not differ significantly according to demographic and clinical characteristics, however, there were more nonwhite patients in the deferoxamine arm than in the placebo arm, however. In addition, thalamic hemorrhage and intraventricular hemorrhage were more common in the placebo-treated group and hemorrhages in the putamen and basal ganglia were more common in the deferoxamine-treated group.
The rates of adverse events were comparable between the two study arms. Dr. Selim and his colleagues found no unexpected safety issues. Mortality was low, and the 90-day and 180-day mortality rates were comparable between the two treatment arms.
Approximately 34% of deferoxamine-treated patients and 33% of placebo-treated patients had an mRS score of 0-2 at 90 days. The adjusted absolute risk difference between arms was 0.6%; this result did not surpass the predefined futility threshold. The risk difference between groups for mRS score of 0-2 at 180 days was 8.6% in favor of deferoxamine, which did surpass the futility threshold.
The risk difference for meeting the secondary endpoint was 6.2% in favor of deferoxamine; this result did not surpass the futility threshold. Patients in both treatment groups improved between day 90 and day 180. The likelihood of good outcome was approximately 10% higher in the deferoxamine group at day 90 and 26% higher in the deferoxamine group at day 180.
“It is futile to conduct a phase 3 trial with the anticipation that treatment with deferoxamine would improve outcome, defined as mRS score of 0-2 at 90 days,” said Dr. Selim. “These data, together with the data from MISTIE and CLEAR, suggest that ICH trials need to have a longer follow-up period to capture the full extent of recovery after ICH. Several of our secondary analyses tended to favor deferoxamine over the placebo arm and leave open the possibility that deferoxamine might lead to improved outcome at 180 days.”
The researchers received support from the NIH and the National Institute of Neurological Disorders and Stroke.
SOURCE: Selim MH et al. ISC 2019, Abstract LB22.