Slide 1 of 26 Iron Chelator Basics Ali T. Taher, MD Professor of Medicine Haematology-Oncology Division American University Beirut Medical Center Beirut, Lebanon

Slide 2 of 26 Outline Goals of iron chelator therapies and strategies Comparison and contrast between current iron chelators Update in efficacy and safety/tolerability of iron chelators –New data on myocardial iron removal –Update on long-term tolerability of iron chelators –High-dose (>30 mg/kg/day) efficacy and safety

Slide 3 of 26 Goals of Iron Chelation Therapy Maintain iron balance with “safe” tissue iron levels –Prevention  Match transfused iron with chelated (excreted) iron  Prevent iron from reaching levels at which tissue damage occurs –Rescue  Remove excess iron—slow process—finite pools  Reverse dysfunction Detoxification of labile iron—24-hour protection –Extracellular (non–transferrin-bound iron, labile plasma iron) –Intracellular (labile iron pool) Wide therapeutic safety margin of regimen

Slide 4 of 26 Properties of an Ideal Iron Chelator To control body iron –High and specific affinity for Fe 3+ –High chelating efficiency To minimize iron toxicity –24-hour coverage –Slow metabolism and elimination rate –Good tissue penetration with stable iron complex Acceptable efficacy–toxicity profile –Clear drug–dose relationship with efficacy and toxicity –No iron redistribution Simplicity and ease of monitoring Patient acceptance/compliance –Oral bioavailability –Suitable for monotherapy

Slide 5 of 26 Decreasing Cellular Toxicity with Chelators By inhibiting non–transferrin-bound iron uptake By directly chelating labile intracellular iron By preventing the incorporation of this iron into new ferritin synthesis By intercepting iron derived from lysosomal degradation of ferritin Porter JB. Am J Hematol. 2007;82: Effective mechanisms for the action of chelation therapy

Slide 6 of 26 Overview of Iron Chelators PropertyDesferrioxamine 1 Deferiprone 2 Deferasirox 3 Usual dose25–60 mg/kg/d75 mg/kg/d20–30 mg/kg/d RouteSC, IV 8–12 h, 5 d/wk PO 3 times daily PO Once daily Half-life20–30 min3–4 h8–16 h ExcretionUrinary, faecalUrinaryFaecal Adverse effectsLocal reactions, ophthalmologic, auditory, growth retardation, allergic GI disturbances, agranulocytosis/neutropenia, arthralgia, elevated liver enzymes GI disturbances, rash, mild non- progressive creatinine increase, ophthalmologic, auditory, elevated liver enzymes StatusLicensedNot licensed in the United States or Canada Licensed Approved indications Treatment of chronic iron overload due to transfusion- dependent anaemias Thalassaemia majorTreatment of chronic iron overload due to frequent blood transfusions 1.Desferrioxamine [PI]. Stein, Switzerland: Novartis Pharma Stein AG; Deferasirox [Summary of Product Characteristics] [PI]. Apotex Europe LTD Deferiprone [PI]. West Sussex, UK: Novartis Europharm LT; Abbreviations: GI, gastrointestinal; IV, intravenous; PO, by mouth; SC, subcutaneous.

Slide 7 of 26 Thalassaemia International Federation Guidelines for Iron Chelation in  -Thalassaemia Major TreatmentRecommendation Deferasirox 20 mg/kg/day starting dose in averagely transfused patients 30 mg/kg/day in patients with pre-existing high levels of iron loading 10–15 mg/kg/day for patients with low levels of iron loading Desferrioxamine 20–40 mg/kg for children, ≤50–60 mg/kg for adults In paediatric patients <3 years of age, recommend reduced dose and monitoring of growth and bone development Deferiprone 75 mg/kg/day May be combined with desferrioxamine if desferrioxamine monotherapy is ineffective

Slide 8 of 26 Cardiac T2* and Risk of Cardiac Dysfunction Left Ventricular Ejection Fraction (%) Cardiac T2* (ms) Severe cardiac iron Minimal liver iron Severe liver iron Minimal cardiac iron With permission from Anderson LJ, et al. Eur Heart J. 2001;22:

Slide 9 of 26 Cardiac T2* and Risk of Cardiac Dysfunction Cardiac T2* (ms ) Percentage of Assessments with LVEF <56% Abbreviation: LVEF, left ventricular ejection fraction. With permission from Westwood MA, et al. J Cardiovasc Magn Reson. 2005;7:46-47.

Slide 10 of 26 Mean Change in LIC and Cardiac T2* During 6 Months of Therapy with DFS a in TM Patients Study US04, preliminary data. a Dosage: 30–40 mg (given over 18 months). Abbreviations: DFS, deferasirox; dw, dry weight; LIC, liver iron concentration; TM, thalassaemia major. With permission from Wood J, et al. Blood. 2007;110:abstr Changes in cardiac T2* and LIC (mean ± SE) Cardiac T2* (ms) LIC (mg/g dw) Cardiac T2* (P =.0136) LIC (P =.0027)

Slide 11 of 26 Effect on Oxidant-Stress and Inflammation— DFS vs DFO Mean Decline at 1 Year MarkersDFSDFOP value Tx vs Baseline P value DFS vs DFO Malondialdehyde-21%-25%P =.006 ns C-reactive protein-51% -27% +8.6% +34% NA a P =.02 b P =.02 c a P values not provided. b Confounded by differences in baseline values and missing baseline data. c Controlled for confounding differences and missing baseline data. Abbreviations: DFO, desferrioxamine; DFS, deferasirox. Walter PB, et al. Haematologica. 2008;93:

Slide 12 of 26 Effect on Oxidant-Stress and Inflammation— DFS vs DFO Conclusions Liver iron concentrations and ferritin declined significantly in both treatment groups, paralleling a significant decline in malondialdehyde C-reactive protein decreased significantly only in patients receiving DFS, although this finding should be interpreted with caution Abbreviations: DFO, desferrioxamine; DFS, deferasirox. Walter PB, et al. Haematologica. 2008;93:

Slide 13 of 26 Deferasirox—3.5 Years of Data TrialPatient PopulationPhaseDesignNEnd-Points 106PaediatricThalIISingle arm DFS 10 mg/kg/d 401° safety 2° LIC by SQUID 107Adult, paediatric ThalIIIRandomized DFS 5  30 mg/kg/d vs DFO 20  60 mg/kg/d 5861° LIC by biopsy or SQUID 2° tolerability 108Adult, paediatric Thal, MDS, rare anaemias IISingle arm DFS 5  30 mg/kg/d 86 thal 98 other 1° LIC by biopsy or SQUID 2° tolerability 109Adult, paediatric SCDIIRandomized DFS 10  30 mg/kg/d vs DFO 20  60 mg/kg/d 1951° safety 2° LIC by SQUID 652 patients have received DFS for a median of 3.4 years (range 0–4.5) Extension studies: 312 patients crossed over from DFO to DFS: median of 2.2 years on DFS (range 0–2.9) Efficacy analysis based on DFS extension trials: β -thalassaemia: 421; other anaemias: 231 Abbreviations: DFO, desferrioxamine; DFS, deferasirox; LIC, liver iron concentration; SCD, sickle cell disease; SQUID, superconducting quantum interference device; Thal, thalassaemia.. Cappellini MD, et al. ASH December 8-10, Poster 967. Porter J, et al. ASH December 8-10, Poster 968.

Slide 14 of 26 Median Change in Serum Ferritin Levels from Baseline (By Initial Dose Group) −1500 − Time Since Start of Treatment (months) Median Change in Serum Ferritin Levels (µg/L) 0 Core Extension 5–10 (n = 227)20 (n = 182)30 (n = 243) Initial deferasirox dose, mg/kg/day Studies 106–109 With permission from Porter J, et al. ASH December 8-10, Poster 968.

Slide 15 of 26 Deferasirox—Long-Term Efficacy Long-term data highlights –The importance of regularly monitoring serum ferritin levels –Ensuring that patients receive the appropriate deferasirox dose, based on iron burden and transfusional iron intake to reach therapeutic goal In general, serum ferritin levels decreased at deferasirox doses of 30 mg/kg/day and were maintained at doses of 20–25 mg/kg/day Treating to a target serum ferritin level of 500 μg/L is a realistic goal Porter J, et al. ASH 2007; December 8-10, 2007.

Slide 16 of 26 Most Common (> 4% overall) Drug-Related Adverse Events During 3.5 Years of Treatment a Adverse eventFrequency, n (%)Severity, n (%) MildModerateSevere Nausea 99 (10.3)84 (8.7)14 (1.5)1 (0.1) Diarrhoea86 (8.9)68 (7.1)16 (1.7)2 (0.2) Vomiting60 (6.2)46 (4.8)13 (1.3)1 (0.1) Abdominal pain50 (5.2)36 (3.7)10 (1.0)4 (0.4) Rash50 (5.2)28 (2.9)19 (2.0)3 (0.3) Upper abdominal pain48 (5.0)37 (3.8)10 (1.0)1 (0.1) a Total number of patients: 964. With permission from Cappellini MD, et al. ASH December 8-10, Poster 967. Drug-related adverse events during deferasirox treatment were generally transient and of mild-to-moderate severity Studies 106–109

Slide 17 of 26 Serum Creatinine Increase During 3.5 Years of Treatment 2 Consecutive Serum Creatinine Values >33% Above Baseline 2 Consecutive Serum Creatinine Values >33% Above Baseline and Beyond the ULN β-thalassaemia (n = 680) 284 (41.8%)39 (5.7%) Other anaemias (n = 284) 92 (32.4%)36 (12.7%) No patient has developed progressive increases in serum creatinine values >2 x ULN 2 patients discontinued due to stable creatinine increases of 1.5 x ULN and confounding circumstances (concomitant cyclosporin and multiple infections, respectively) With permission from Cappellini MD, et al. ASH December 8-10, Poster 967. Studies 106–109 Abbreviation: ULN, upper limit of normal.

Slide 18 of 26 Hepatic Safety During 3.5 Years of Treatment 8 patients (0.8%) experienced an ALT value at 2 consecutive visits that exceeded 10 x ULN; ALT already exceeded ULN at baseline in 6 of these patients Discontinuation –1 patient due to recurrent episodes of proteinuria –12 patients due to increases in transaminases Drug-induced liver toxicity was suspected in 2 patients with early onset and positive re-challenge In patients who showed increased LIC, underchelation was the likely explanation in at least some of the cases Studies 106–109 Abbreviations: ALT, alanine transaminase; LIC, liver iron concentration; ULN, upper limit of normal. Cappellini MD, et al. ASH December 8-10, Poster 967.

Slide 19 of 26 Deferasirox >30 mg/kg/d Efficacy PopulationnRelative Change vs Levels Before Dose Escalation (%) Absolute Change vs Levels Before Dose Escalation (µg/L) P value All patients223– 9.4 – 407<.001 β-thalassaemia195 – 12.0 – 437<.001 Sickle cell disease23– 0.6– 26NS Other anaemias5 – 11.0 – 703– Adults117– 6.8 – Paediatrics103 – 15.2 – 572<.001 P values based on paired Wilcoxon test; absolute serum ferritin changes vs pre-escalation. Abbreviation: NS, nonsignificant. Median of relative and absolute change in serum ferritin levels at last observed assessment after dose escalation to >30 mg/kg/day, by subgroup (efficacy population) With permission from Taher A, et al. Thalassemia International Federation October 8-11, Abstract CHE40.

Slide 20 of 26 Deferasirox >30 mg/kg/day Safety Adverse eventFrequency, n (%) Before Dose EscalationAfter Dose Escalation Median exposure (wk) ALT increase12 (5.4)7 (3.1) Vomiting17 (7.6)6 (2.7) Abdominal pain15 (6.7)3 (1.3) Abdominal pain upper3 (1.3) Nausea24 (10.7)3 (1.3) Serum creatinine increase13 (5.8)3 (1.3) Rash19 (8.5)2 (0.9) Diarrhoea12 (5.4)2 (0.9) Most common drug-related adverse events, as assessed by investigators (observed in >1 patient after dose escalation to >30 mg/kg/day) Abbreviation: ALT, alanine transaminase. With permission from Taher A, et al. Thalassemia International Federation October 8-11, Abstract CHE40.

Slide 21 of 26 Deferasirox >30 mg/kg/day Serum Creatinine Serum creatinine levels remained unchanged after dose escalation >30 mg/kg/day (overall population) − 9− 9− 6− 6− 3− 3 Baseline Dose escalation to >30 mg/kg/day Time (months) Serum Creatinine Levels (µmol/L) With permission from Taher A, et al. Thalassemia International Federation October 8-11, Abstract CHE40.

Slide 22 of 26 Deferasirox >30 mg/kg/day—ALT Adverse Events 12 patients (5.4%) had ALT levels 5 x ULN at 2 consecutive assessments at least 7 days apart, 10 of whom had ALT >ULN prior to receiving deferasirox 1 patient, who had ALT >ULN prior to deferasirox treatment, had ALT values 10 x ULN at 2 consecutive visits after dose escalation Abbreviations: ALT, alanine aminotransferase; ULN, upper limit of normal.

Slide 23 of 26 Long-Term Efficacy— DFP vs DFO vs DFP + DFO (N = 64 patients with β -thalassaemia) Mean T2* Myocardial Iron (msec) DFO DFP a DFP + DFO b (+/- 13)(+/- 18.3)(+/- 15.3) a DFO vs DFP: P =.02 b DFO vs DFO + DFO: P =.001 Dosages: DFO (30–50 mg/kg/d, >5 d/wk); DFP (75 mg/kg/d); DFO (30–50 mg/kg/d, >5 d/wk) + DFP (75 mg/kg/d) Abbreviations: DFO, desferrioxamine; DFP, deferiprone. Perifanis V, et al. Int J Hematol. 2007;86:

Slide 24 of 26 Long-Term Efficacy— DFP vs DFO vs DFP + DFO (N = 64 patients with β -thalassaemia) Mean T2* Hepatic Iron (msec) DFO a DFPDFP + DFO b (+/- 8.4)(+/- 2.5)(+/- 10.9) a DFP vs DFO: P =.014 b DFP vs DFO + DFP: P =.003 Dosages: DFO (30–50 mg/kg/d, >5 d/wk); DFP (75 mg/kg/d); DFO (30–50 mg/kg/d, >5 d/wk) + DFP (75 mg/kg/d) Abbreviations: DFO, desferrioxamine; DFP, deferiprone. Perifanis V, et al. Int J Hematol. 2007;86:

Slide 25 of 26 Long-Term Efficacy— DFP vs DFO vs DFP + DFO Conclusions DFO had significantly higher myocardial iron than DFP and DFP + DFO DFP had significantly higher hepatic iron than DFO and DFP + DFO DFO + DFP appears to combine the different benefits of DFO and DFP with respect to cardiac and hepatic iron Abbreviations: DFO, desferrioxamine; DFP, deferiprone. Perifanis V, et al. Int J Hematol. 2007;86:

Slide 26 of 26 Conclusions Ease of administration, ensuring compliance, is an important property in choosing an iron chelator DFS at dose of 30 mg is efficacious and safe with newer dosing being studied (up to 40 mg) Treatment of iron overload may initially require higher doses to achieve iron balance Maintaining iron balance with “safe” tissue iron levels may require lower dose levels Dosage for an individual patient is determined by number of blood transfusions received and patient’s iron burden