Design: Phase 3, randomised, double-blind, placebo-controlled; stopped for futility
Population: 271 patients aged 3–21 with sickle cell acute pain episodes
Primary outcome: Time to crisis resolution (last intravenous opioid dose)
Effect: Median 60.8 vs 65.8 hours; difference 7.2 h (95% CI −21.6 to 35.9)

The phase 3 STArT trial in JAMA (13 October) randomised 271 patients aged 3 to 21 with sickle cell pain crises needing parenteral opioids, in 10 US children's hospitals, to intravenous arginine or saline until discharge.

The trial was stopped early for futility. Median time to crisis resolution was 60.8 hours with arginine and 65.8 hours with placebo, a difference that was not significant. Opioid use, pain scores, patient-reported outcomes and safety did not differ.

Earlier single-centre phase 2 trials had suggested arginine shortened stays and spared opioids, and some centres had begun using it. This larger, blinded trial does not support that. Management of the crisis remains prompt, adequate analgesia, hydration and watching for acute chest syndrome.

Arginine did not shorten crises or reduce opioid use
Do not add intravenous arginine to sickle cell crisis protocols on current evidence
Give timely, adequate opioid analgesia and reassess pain frequently
Watch for acute chest syndrome, especially with chest pain, fever or falling saturation

Why it matters

It closes off a promising-looking treatment that phase 2 trials had encouraged.

The statistics, in plain English

The 95% CI for the difference in resolution time ran from about 22 hours faster to 36 hours slower, so a modest benefit cannot be fully excluded, but the futility stop means a meaningful one was unlikely.