Subcutaneous injection pain with C.E.R.A., a continuous erythropoietin receptor activator, compared with darbepoetin alfa

Abstract

ABSTRACTObjective: This study assessed injection site pain following subcutaneous (SC) administration with a continuous erythropoietin receptor activator (C.E.R.A.), compared with darbepoetin alfa in healthy adults.Methods: In a randomized, placebo-controlled, single-centre, single-blind, three-way crossover study, subjects received one of six treatment sequences (ABC/ACB/BAC/BCA/CBA/CAB) involving SC injection of (A) C.E.R.A. 50 μg, (B) darbepoetin alfa 50 μg, or (C) placebo on days 1, 29, and 57. An initial pilot phase (n = 12) was used to determine the sample size for the confirmatory phase (n = 72), and data were combined for the final analysis (n = 84).Main outcome measures: The primary endpoint was pain on the 100 mm visual analog scale (VAS) immediately after dosing. Secondary endpoints included VAS at 1 hour after dosing and pain on the six-point verbal rating scale (VRS) immediately and at 1 hour after dosing.Results: C.E.R.A. was associated with significantly less pain immediately after SC injection compared with darbepoetin alfa: least squares mean VAS 21.5 (95% confidence interval [CI]: 17.5, 25.5) versus 33.4 (95% CI: 28.4, 38.4) ( p < 0.0001). Incidence of pain on the VRS was lower with C.E.R.A. compared with darbepoetin alfa immediately after dosing ( p < 0.0001). One hour after administration, most subjects had no VRS pain. A study limitation is the small sample size and the findings need to be confirmed in a large trial of chronic kidney disease patients.Conclusions: SC injection with C.E.R.A. is significantly less painful than SC darbepoetin alfa in healthy adults. Treatment of anemia in chronic kidney disease with SC injection of C.E.R.A. may provide a lower pain burden compared with darbepoetin alfa.