Arginine therapy of limited benefit for acute pain episodes in sickle cell disease

Arginine therapy is no better than placebo in terms of improving outcomes in children and young adults with sickle cell disease (SCD) who are experiencing acute pain episodes, according to the phase III STArT trial.

STArT included 271 SCD patients aged 3–21 years (mean age 14.3 years, 51 percent male, 92 percent Black) presenting to the emergency department with acute pain episodes requiring parenteral opioids. These patients were randomly assigned to receive intravenous arginine (200 mg/kg followed by 100 mg/kg every 8 h until discharge; n=129) or saline placebo (n=142).

The primary outcome was time to crisis resolution, defined as hours from initial study drug delivery to last intravenous opioid dose. Total parenteral opioid use (intravenous morphine equivalents from first study drug dose to last intravenous opioid dose), pain scores, and patient-reported outcomes were also assessed as secondary outcomes.

The trial was terminated prematurely for futility. The median time to crisis resolution was 60.8 h in the arginine group vs 65.8 h in the placebo group. The absolute difference of 7.2 h (95 percent confidence interval, −21.6 to 35.9) was not significant.

Similarly, total parenteral opioid use, pain scores, patient-reported outcomes, and safety events did not significantly differ between the arginine and placebo groups.