Anaemia treatment in CKD, ESRD, and kidney transplant recipients Iain C Macdougall BSc, MD, FRCP Consultant Nephrologist and Honorary Senior Lecturer Renal Unit, King’s College Hospital, London, UK

Outline of presentation Erythropoiesis in 2009 ESA therapy Target Hb Iron management Anaemia management in kidney transplantation The future

Development of renal anaemia prior to the availability of EPO therapy 15 Hb (g/dL) 10 Dialysis 5 CKD stages 1–2 Stage 3 4 5 120–60 59–30 29–15 < 15 Declining GFR (mL/min) NHANES data

Erythropoiesis in CKD Erythropoiesis in CKD in 2009 Erythropoietin Iron SCF, GM-CSF, IL-3 SCF, IL-1, IL-3, IL-6, IL-11 About 8 Days Pluripotent Stem Cell Burst-Forming Unit-Erythroid Cells (BFU-E) Colony-Forming Unit-Erythroid Cells (CFU-E) Proerythro- blasts Erythro- blasts Reticulocytes RBCs Papayannopoulou T, et al. In: Hoffman R, et al., ed. Hematology: Basic Principles and Practice. 4th ed. 2005;267-288.

Erythropoiesis in CKD in 2009 EPO +  Fas Ag Apoptosis ─ + Iron  Fe absorption  Fe transport  Fe availability (EPO-R, Tf, TfR, Ferriportin, DMT-1) ─  EPO production Pro-inflammatory cytokines (IL-1, TNFα, IL-6, IFNγ) hepcidin

Anti-Anaemic therapies in CKD Erythropoietin Iron SCF, GM-CSF, IL-3 SCF, IL-1, IL-3, IL-6, IL-11 About 8 Days Pluripotent Stem Cell Burst-Forming Unit-Erythroid Cells (BFU-E) Colony-Forming Unit-Erythroid Cells (CFU-E) Proerythro- blasts Erythro- blasts Reticulocytes RBCs Papayannopoulou T, et al. In: Hoffman R, et al., ed. Hematology: Basic Principles and Practice. 4th ed. 2005;267-288.

Outline of presentation Erythropoiesis in 2009 ESA therapy Target Hb Iron management Anaemia management in kidney transplantation The future

Development of recombinant human EPO 1977 - human EPO isolated from 2,500 litres of urine (Miyake et al) 1983 - gene for human EPO isolated and cloned (FK Lin et al) 1986 - first clinical report in dialysis patients 1990 - r-HuEPO licensed for use in Europe

Epoetin alfa (Eprex) Epoetin beta (NeoRecormon)

Development of renal anaemia prior to the availability of EPO therapy 15 EPO Hb (g/dL) Winearls CG, et al. (Lancet 1986; 2: 1175-8) Eschbach JW, et al. (N Engl J Med 1987; 316:73-8) Macdougall IC, et al. (Lancet 1990; 335: 489-93) 10 Dialysis 5 CKD stages 1–2 Stage 3 4 5 120–60 59–30 29–15 < 15 Declining GFR (mL/min)

Macdougall et al., Lancet 1990; 335: 489-493.

Hb increment > 5g/dl Mean baseline Hb = 6.3g/dl Hb (g/dl) EPO 14 12 Hb increment > 5g/dl 10 Hb (g/dl) 8 Mean baseline Hb = 6.3g/dl 6 EPO 2 4 6 8 10 12 Time (months) Macdougall et al., Lancet 1990; 335: 489-493. 3 3 3

Strategies for treating renal anaemia Hb (g/dl) Prevention Higher target 15 Earlier start 2002 1998 1994 Dialysis 10 1990 5 Time or creatinine

Anaemia therapy in CKD Initially, Epoetin alfa (Eprex, Erypo) – 1990 Epoetin beta (NeoRecormon) – 1990 Epoetin alfa Epoetin beta

Anaemia therapy in CKD Initially, 2nd generation ESA:- Epoetin alfa (Eprex, Erypo) – 1990 Epoetin beta (NeoRecormon) – 1990 2nd generation ESA:- Darbepoetin alfa (Aranesp) – 2001 Epoetin alfa Epoetin beta

Darbepoetin alfa: a molecule with two more N-linked glycosylation chains than r-HuEPO Second extra N-linked chain First extra N-linked chain Five amino acids on the rHuEPO polypeptide backbone were changed to introduce two new N-linked carbohydrate recognition sites, resulting in Aranesp®. Aranesp® is about 51% carbohydrate by weight, and its two extra carbohydrate side chains attach precisely in the region where the amino acid sequence has been altered. Although space-filling models of Aranesp® based on crystallographic data do not show us the carbohydrate side chains, the extra glycosylation sites of Aranesp® tend to be covered by two tetraantennary glycans. These are the largest of the three kinds of carbohydrate chain (bi-, tri- and tetraantennary), and contribute to the maximal biological activity of Aranesp®.

Third-generation ESAs C.E.R.A. (MIRCERA) Methoxy polyethylene glycol epoetin beta – licensed 2007

C.E.R.A. Continuous Erythropoietin Receptor Activator EPO PEGylated Epoetin beta

Epoetin delta (DYNEPOTM)

Biosimilar EPOs First biosimilar epoetins licensed in Europe – BinocritTM (Sandoz) – RetacritTM (Hospira)

Current licensed ESAs in Europe Epoetin alfa (Eprex) Epoetin beta (NeoRecormon) Darbepoetin alfa (Aranesp) C.E.R.A. (MIRCERA) Epoetin delta (Dynepo) Biosimilar Epoetin alfa (Binocrit) Biosimilar Epoetin zeta (Retacrit) A comprehensive clinical candidate development program was undertaken to identify a new agent to improve anemia management. A variety of options were explored, including hyperglycosylated variants of epoetin, dimers of epoetin, peptides and other small molecules, synthetic proteins, gene therapy, and integration of polymers such as polyethylene glycol. The integration of specific polyethylene glycol moieties was selected for further exploration.

IV half-lives of ESA therapy

Simulation of EPO kinetics for short-acting ESAs vs longer-acting ESAs* Epoetin (TIW) Plasma ESA (ng/ml) 100 10 1 0.1 0.01 0 12 24 36 48 days *estimated values based on 6000 IU epoetin / week

Simulation of EPO kinetics for short-acting ESAs vs longer-acting ESAs* Epoetin (TIW) Darbepoetin (QW) Plasma ESA (ng/ml) 100 10 1 0.1 0.01 0 12 24 36 48 days *estimated values based on 6000 IU epoetin / week

Simulation of EPO kinetics for short-acting ESAs vs longer-acting ESAs* Epoetin (TIW) Darbepoetin (QW) C.E.R.A. (QM) Plasma ESA (ng/ml) 100 10 1 0.1 0.01 0 12 24 36 48 days *estimated values based on 6000 IU epoetin / week

ESAs Dosing frequency x2 or x3 / week x1/wk or x1/2wks Short-acting x2 or x3 / week Medium-acting x1/wk or x1/2wks Long-acting x1/2wks or x1/mth

Outline of presentation Erythropoiesis in 2009 ESA therapy Target Hb Iron management Anaemia management in kidney transplantation The future

Hb predicts survival in observational studies HD patients Ofsthun et al, Kidney Int 2003; 63: 1908-1914.                                                       

Hb predicts survival in observational studies ND-CKD patients Levin A. et al, Nephrol Dial Transplant 2006; 21: 370-377.

US Normal Haematocrit Trial Besarab A et al. N Engl J Med 339: 584-590, 1998.

US Normal Haematocrit Trial - probability of death or first non-fatal MI 60 Normal-haematocrit group 50 40 Low-haematocrit group Probability of death or MI (%) 30 20 10 0 3 6 9 12 15 18 21 24 27 30 Months after randomization Besarab et al. NEJM 1998; 339: 584-90.

CREATE CHOIR

CREATE 1

Primary endpoint Time to first CV event (105 events) Events: 58 vs 47 HR=0.78 (0.53–1.14) Log rank test p=0.20

CHOIR 1

CHOIR Trial 125 vs 97 events; p < 0.03

Hb target ranges – the evidence Sources:- – Lancet meta-analysis – K/DOQI Anemia Guidelines update (evidence review by Boston Tufts University Evidence Rating Group) 15 14 13 Hb (g/dl) Key message CKD patients have a higher risk for poor outcomes compared to those with normal eGFR. Data was accumulated from four community-based longitudinal cohort studies carried out in the USA between 1987 and 1993: Atherosclerosis Risk in Communities Study, the Cardiovascular Health Study (CHS), the Framingham Heart Study (FHS) and the Framingham Offspring Study (Offspring). Analyses from 22,634 patients were included with a mean follow-up time of 99 months. CV events refers to myocardial infarction or fatal coronary heart disease. 12 11 10 9 Weiner et al., Chronic kidney disease as a risk factor for cardiovascular disease and all-cause mortality: a pooled analysis of community-based studies J Am Soc Nephrol 2004; 15:1307-1315

Outline of presentation Erythropoiesis in 2009 ESA therapy Target Hb Iron management Anaemia management in kidney transplantation The future

Why are CKD patients prone to develop iron deficiency? REDUCED INTAKE Poor appetite Poor G-I absorption Concurrent medication – e.g. omeprazole Food interactions Occult G-I losses Peptic ulceration Blood sampling Dialyser losses Concurrent meds. – e.g. aspirin Heparin on dialysis INCREASED LOSSES

Iron metabolism Serum TfR PLASMA Serum iron/TIBC TSAT stores PLASMA Serum iron/TIBC TSAT Marrow stainable iron Ferritin % hypochromic RBC CHr RBC ZPP

Monitoring iron status Minimum ranges: Serum ferritin > 100 g/l Hypochromic RBC < 10% TSAT > 20% Aim for : Serum ferritin 200-500 g/l Hypochromic RBC < 2.5% TSAT 30-40%

IV Iron Agents are Spheroid Particles with an Iron Core and a Carbohydrate Shell oxyhydroxide core carbohydrate shell

DOPPS III: Type of IV Iron Prescribed in HD patients Fe-Oxide Saccharate Polymaltose Other Dextran Cideferron Gluconate Patients (%) - Sucrose n = (393) (396) (333) (339) (419) (304) (566) (469) (449) (334) (1327) Chondroitin SO4 DOPPS III data (2005-07), among prevalent cross-section of HD patients using IV iron.

Benefits of IV iron in CKD patients  IV iron can improve the anaemia of CKD even in the absence of ESA therapy  IV iron can significantly enhance the response to ESA therapy, even in iron-replete patients

Potential dangers of IV iron ? Short-term Anaphylactic reactions (iron dextran only; dextran Abs) “Free iron” reactions (all IV iron preparations) Long-term Increased susceptibility to infection Increased oxidative stress Iron overload

Balance of benefits vs. risks of IV iron  Mortality risk Oxidative stress Infection risk Anaphylaxis Benefits of IV iron

Outline of presentation Erythropoiesis in 2009 ESA therapy Target Hb Iron management Anaemia management in kidney transplantation The future

Prevalence of anaemia in European kidney transplant recipients Hb < 12 g/dl : 28.4% Hb < 12 g/dl : 22.7% Overall 24.5 % were anaemic Hb < 12 g/dl : 25.5% Hb < 12 g/dl : 24.4% n = 4263 - 76 centres, 16 countries Y Vanrenterghem et al., For TRESAM, Am J Transplantation 2003

Prevalence of severe anaemia in Europe Overall 8.5% with severe anaemia Hb < 11 g/dl Hb < 10 g/dl Among 8.5% patients with severe anaemia, 18% were on EPO therapy Y. Vanrenterghem et al., for TRESAM, Am J Transplantation 2003.

Post-transplantation anaemia Causes – iron deficiency – infections (CMV) – immunosuppresssive therapy – ACE-I / ARB therapy – impaired renal function ( EPO) – failing graft (pro-inflammatory cytokines) 51

ESA hyporesponsiveness in renal transplantation Iron deficiency Infection/ inflammation Underdialysis Hyperparathyroidism Aluminium toxicity Carnitine deficiency PRCA Blood loss Haemolysis B12/folate deficiency Marrow disorders Haemoglobinopathies ACE inhibitors Viral (CMV, EBV, Parvovirus) Malignancy (e.g. lymphoma) Immunosuppression (Aza, MMF, SRL)

Outline of presentation Erythropoiesis in 2009 ESA therapy Target Hb Iron management Anaemia management in kidney transplantation The future

Clin J Am Soc Nephrol, 2008 1

Hematide EPO-mimetic peptide, now in Phase III clinical trials Amino acid sequences completely unrelated to native EPO Shows same functional / biological properties as EPO 2

What is different about Hematide? Peptide-based (epoetin, darbepoetin, CERA – all protein-based) Not genetically-engineered in cells (unlike epoetin, darbepoetin, CERA) Manufactured by synthetic peptide chemical techniques ? More stable at room temperature ? less immunogenic Does not cross-react with antibodies against EPO – should not cause PRCA; can be used to treat Ab+PRCA First ESA to be tested de novo once-monthly in CKD patients

Anti-EPO antibodies do not neutralise Hematide EPO, rHuEPO Darbepoetin alfa C.E.R.A. Peg-rHuEPO EPO-mimetic peptide Jak2 P Jak2 P Jak2 P Jak2 P membrane Signal Transduction Gene Activation Survival, differentiation, proliferation, and maturation of RBC progenitors and precursors

Hematide in the Treatment of Antibody-Mediated Pure Red Cell Aplasia Hematide in the Treatment of Antibody-Mediated Pure Red Cell Aplasia I C Macdougall et al, ASN 2007 (updated in 2008) n = 13 13 13 11 11 10 9 8 7 8 6 7 7 6 6 7 6 6 6 6 6 6 6 6 6 5 6 6 5 4 3 2 (Data from three subjects were censored due to kidney transplantation) 10 20 30 40 50 60 BL 1 2 3 4 5 6 7 8 9 11 12 13 14 15 16 17 18 19 21 22 23 24 25 26 27 28 29 31 32 Study Months Percent Patients Receiving RBC Transfusions During Each Study Month 8.0 9.0 10.0 11.0 12.0 13.0 14.0 Mean (SD) Hb Concentration (g/dL) 58 58

HIF stabilisers Upside Downside HIF is the hypoxic sensor that upregulates EPO gene expression HIF is broken down by a prolyl hydroxylase enzyme An inhibitor of HIF hydroxylase has been synthesised (FibroGen) It causes an increase in EPO levels, even in CKD patients Upside This enzyme inhibitor is orally-active Downside >100 other genes (e.g. VEGF) also turned on Rare development of severe liver toxicity (may be fatal) 2

New IV irons pending……. 2 new IV irons forthcoming:- – Ferumoxytol (US) – Ferric carboxymaltose – FerinjectTM (Europe) Advantages – ? safer – no need for test dose – more rapid high-dose bolus injection – main benefits in the pre-ESRD population

Ferric carboxymaltose (Ferinject)  Ferric hydroxide molecules  Ribbon-like carboxymaltose Licensed in Europe Stable iron complex Low immunogenic potential – dextran-free Minimal detectable and releasable free iron No test dose required Rapid administration – 200mg push – 500mg in 6 mins – 1000mg infusion in 15 mins

Ganz, 2006.

Ganz, 2006.

Iron transport

EPO: an all-purpose tissue-protective agent? Savino R, Ciliberto G. Cell Death Differ. 2004;11 Suppl 1:S2-4.

EPO therapy: beyond Hb Mediated via the anti-apoptotic action of EPO on non-erythroid cells Relevant for acute cardiac, renal, and cerebral ischaemia ? Therapeutic benefit in :- – Acute MI – Acute stroke – Reperfusion injury – Post-transplantation 1

Conclusions Our understanding of erythropoiesis in 2009 has advanced to include the role of hepcidin and pro-inflammatory cytokines Until further evidence is forthcoming, we should generally target an Hb of 11–12 g/dl Even in 2009, there is still a need for additional grade A level evidence in the management of anaemia in CKD Several new ESAs and IV iron preparations are appearing, and the non-erythropoietic effects of ESAs are being explored BA16738 – 132 patients in CERA arm SC, 52 week treatment period (18 week correction, 10 week evaluation, 24 week extension) 264 BA16736 – 126 patients in the CERA arm IV, 52 week treatment period (24 week correction, 28 week evaluation) 168 BA16739 – 310 patients in 2 CERA arms IV, 52 week treatment period 465 BA16740 – 310 patients in 2 CERA arms SC, 52 week treatment period 465 BA17284 – 132 patients in the CERA arm pre-filled syringes, 36 week treatment period 264 BA17283 – 132 patients in the CERA arm IV, 52 week treatment period 264 Total 897 IV patients Total 729 SC patients