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

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.

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 microg, (B) darbepoetin alfa 50 microg, 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).

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.

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.

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.