Johnson & Johnson's anaemia treatment Procrit (epoetin alfa) is more effective at boosting red blood cells in patients undergoing cancer chemotherapy than rival drug Aranesp (darbepoetin alfa) from Amgen, according to a just-published clinical trial.

Aranesp, first introduced in 2001, has made strong gains in the market for

red cell-stimulating drugs, helped by its long half life that reduced the dosing frequency of anaemia treatment from two or three times a week to once

a week or every fortnight. The latest clinical trial, published in The Oncologist (September 2005) and sponsored by J&J subsidiary Ortho Biotech, suggests that this improvement in dosing may have a trade-off in efficacy.

J&J badly needs some good news to give Procrit a push, as sales of the drug

have been declining on the back of strong competition from Aranesp. Worldwide sales of Procrit dropped 11% to $1.16 billion in the first half of this year [[20/07/05b]]. In the same period, Aranesp put in a 36% sales increase to $1.56 billion, while Amgen's older red cell stimulator Epogen (epoetin alfa) - which has a similar dosing profile to Procrit - also managed a 1% increase to $1.2 billion [[20/07/05d]].

In the head-to-head trial, 47% of patients treated with Procrit achieved the

primary endpoint of the study - an increase in haemoglobin of one gram or

more per decilitre of blood - compared to 33% of patients who received

Aranesp. Those treated with J&J's drug also had a reduced need for transfused blood, said J&J. The proportion of patients needing a transfusion

was not statistically-different between the two treatment groups. However,

when a transfusion was needed, Procrit patients required significantly less

blood than those on Aranesp (2.5 versus 3.9 units).

Amgen recently filed for approval of a new regimen for Aranesp that would

cut dosing down to once every three weeks [[09/05/05f]].