The retrospective chart review, which began analysing data last week according to a posting on US registry ClinicalTrials.gov, is designed to assess what impact switching from darbepoetin alfa, the active ingredient in Amgen's Aranesp, to epoetin zeta has had on CKD patients.
The impact of the change will be measured using a range of disease metrics Amgen said.
“This study will look at the retrospective data of patients that have switched from Darbepoetin Alfa to an approved epoetin alfa biosimilar. Data to be collected includes haemoglobin measurements, dose requirements, iron use, any transfusions, hospitalisations and other lab values including TSAT, Ferritin and albumin.”
Kidney disease market
Amgen’s blockbusting blood cell production booster has dominated the CKD treatment market and earned the US biopharmaceutical firm around $40bn since 1989.
Aranesp’s active pharmaceutical ingredient is darbepoetin alfa, a recombinant version of erythropoietin (EPO) that is produced in Chinese hamster ovary (CHO) cells using recombinant DNA technology.
The drug is protected by patents in Europe and the US that do not expire until July 2016 and May 2024, respectively.
However, Amgen has already faced competition in Europe from Stada’s Silapo and Hospira’s Retacrit, which are both biosimilars of another Amgen drug - the anaemia treatment Epogen (epoetin zeta).
The European Medicines Agency (EMA) approved both Silapo and Retacrit to boost RBC counts in CKD patients in 2007.
Similarly, in India Aranesp faces competition from Cipla and Hetero Drugs’ Actorise, which was approved in June, and from Dr Reddy’s Laboratories Cresp, which was cleared in March 2010. Both drugs are “similar biologics” under Indian regulations.
Also, as Amgen's Clinicaltrial.gov submission points out, Australia's Therapeutic Goods Administration (TGA) approved Sandoz's Novacrit for the treatment of CKD in 2010.
Amgen's biosimilar comparison study, which is taking place at sites in Bulgaria, Greece, Italy, Poland and Spain is expected to examine data from 320 patients and to complete in March 2015.