Despite the abundant laboratory evidence of platelet activation and inflammation in sickle cell disease (SCD), the contribution of these changes to the pathogenesis of SCD remains uncertain. Patients with SCD exhibit increased platelet activation in the non-crisis, “steady state,” and further increases with acute pain episodes. In addition, levels of the inflammatory mediator, CD40 ligand (CD40L) are increased in the plasma and significantly reduced in the platelets of SCD patients compared to healthy individuals. CD40L may contribute to the pathogenesis of acute pain episodes. Despite an improved understanding of the pathophysiology of SCD, the treatment of acute pain episodes is supportive. We performed a randomized, placebo-controlled study to evaluate the safety and efficacy of eptifibatide, a synthetic peptide inhibitor of the glycoprotein (GP) IIb/IIIa receptor, in patients with SCD during acute painful episodes.
In this single site placebo-controlled trial, eligible patients admitted for acute painful episodes received eptifibatide (two 180 mg/kg boluses 10 minutes apart, followed by a continuous infusion at 2 mg/kg/min for 6 hours) or placebo at a ratio of 2:1. The Post-Treatment Phase lasted for up to 7 days or until resolution of the crisis, whichever was shorter, but no less than 24 hours after discontinuation of infusion. The Follow-up Phase included safety evaluations obtained 14 to 17 days and 28 to 35 days after discontinuation of infusion. The primary outcomes were major bleeding episodes and the largest observed decrease in platelet count during the study. We also evaluated the effect of eptifibatide on the duration of acute pain episodes, pain intensity, duration of hospitalization, total opioid use and acute chest syndrome.
Thirteen patients (SS - 10, Sb0 - 2, SC - 1) were randomized to receive either eptifibatide (N=9; 6 females; median age - 25 years) or placebo (N=4; 3 females; median age - 31 years). One patient in the eptifibatide arm withdrew consent following completion of study drug infusion and 1 patient in the placebo arm was withdrawn early because she did not meet eligibility criteria. In the intent-to-treat analysis, there were no major bleeding episodes in either group (point estimate of difference in eptifibatide vs. placebo proportion: 0.0, 95% CI; −0.60, 0.37).There was one minor bleeding episode in a patient on the eptifibatide arm (point estimate of difference in eptifibatide vs. placebo proportion: 0.11, 95% CI: −0.502, 0.494). There was a trend for the largest decrease in platelet count to be greater in the eptifibatide arm compared to the placebo arm, although the difference was not statistically significant (Hodges-Lehman estimate of location shift for eptifibatide vs. placebo: −82, 95% CI; −281, 54). There was no significant difference in the proportion of patients with thrombocytopenia between the treatment groups (point estimate of difference in eptifibatide vs. placebo proportion: 0.11, 95% CI: −0.587, 0.495). The median time to discharge and the median time to crisis resolution were 3.0 days for both treatment arms. The median total opioid use was 400.2 morphine equivalents (ME) for the eptifibatide group and 1471 ME for the placebo group (Hodges-Lehman estimate of location shift for eptifibatide vs. placebo: −65.8, 95% CI: −2519, 1700). There was one episode of acute chest syndrome in each treatment arm.
In this small study of SCD patients hospitalized with acute painful episodes, eptifibatide appeared to be safe, but did not improve the times to crisis resolution or hospital discharge. Eptifibatide was associated with a reduced requirement for opioid analgesics, although the difference was not statistically significant. Clinicaltrials.gov Identifier: NCT00834899.
Parise:BD: Consultancy; Biogen-Idec: Consultancy; NIH: Research Funding; AHA: Research Funding; SCDAC-NIH: Membership on an entity's Board of Directors or advisory committees; BRI Milwaukee: Membership on an entity's Board of Directors or advisory committees. Ataga:Pfizer: Consultancy; HemaQuest Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Adventrx Pharmaceuticals: Consultancy. Off Label Use: Eptifibatide, a glycoprotein IIb/IIIa inhibitor, was evaluated as treatment for acute pain episodes in patients with sickle cell disease.
Asterisk with author names denotes non-ASH members.