YES Antonio M. Risitano, M.D., Ph.D. Hematology Department of - PowerPoint PPT Presentation

The 1st World Congress on Controversies in Hematology Rome, September 4th Do the benefits of complement blockade extend to all patients with PNH clone? YES Antonio M. Risitano, M.D., Ph.D. Hematology Department of Biochemistry and Medical Biotechnologies Federico II University of Naples

CLINICAL CONSEQUENCES OF HEMOLYSIS IN PNH PNH Without the complement inhibitors CD55 and CD59 PNH RBC are susceptible to complement attack Complement activation Fatigue Renal Failure Smooth Muscle Dystonias including Dysphagia, Pulmonary Abdominal Pain, Hemolysis of PNH RBC Hypertension and Male Erectile Dysfunction Thrombosis Hemoglobinuria Anemia

Eculizumab (h5G1.1mAb) Anti-C5 Humanized mAb Human framework regions Variable heavy chain Variable C H light chain 1 C hinge k Murine complementarity Human constant determining regions light chain Ck CH2 Human constant Human constant heavy chain IgG4 CH2 and CH3 heavy chain IgG2 CH1 and hinge CH3

Targeting Complement Inhibitors Classical Pathway Activation Eculizumab Antibody/Antigen Complexes Potent Anaphylatoxin C1q Activated C1 Chemotaxis Cell Lectin Pathway Activation Activation (MBL) C3 Convertase C5 Convertase C4b2a C4+C2 C4b2a3b Weak C5a Anaphylatoxin C3a X Immune Complexes C5b-9 C5 C5b C3 C3b and Microbial Opsonization C6 C7 C8 C9 C3, C3b C3bBb C3bBb3b C3 Convertase C5 Convertase C3H 2 O Factor B+D Cell Activation Alternative Pathway Activation Lysis Microbiological membranes Bacterial LPS Immune Complexes Mammalian Cell Membranes

EFFECT OF ECULIZUMAB ON HEMOLYSIS Lactate dehydrogenase (LDH) 3000 TRIUMPH – Placebo/extension Lactate Dehydrogenase (U/L) TRIUMPH – SOLIRIS/extension 2500 SHEPHERD – SOLIRIS 2000 1500 1000 500 0 0 10 20 30 40 50 Time, Weeks

EFFECT OF ECULIZUMAB ON TRANSFUSIONS Time to first transfusion 100 Patients Avoiding Transfusion (%) 90 44% reduction 80 Eculizumab in PRBC units transfused 70 60 51% 50 40 P < 0.000001 30 20 Placebo 10 0% 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Study Week

� SHEPHERD study: a non randomized trial for broader PNH population – patients with thrombocytopenia and minimal transfusional need 40 1 Year Pre-Treatment 1 Year Post-Treatment 33,5 35 Median Units Packed RBCs 51% of patients 30 treated with eculizumab 25 were transfusion independent (12 m) 20 17 Efficacy 15 demonstrated in all patient cohort 10 8 8 7,5 4 5 2 0 0 0 0 (n = 97) (n = 21) (n = 47) (n = 15) (n = 14) Overall < 4 Units 4 - 14 Units 15 - 25 Units > 25 Units Transfusion Requirements (12 Months Prior to Treatment)

ECULIZUMAB IN NON TRANSFUSED PATIENTS An Italian pilot experience (Risitano et al, EHA 2009) Years Treatment LDH LDH Hb Hb PNH RBC PNH RBC from duration before during befor e during Hb before during Patient Age diagnosis (months) Ecu Ecu Ecu Ecu gain Ecu (%) Ecu (%) 1 41 15 17 680 225 10 12,8 +2,8 n.a. 48 2 25 2 18 1216 356 7,5 10 +2,5 23 60 3 51 10 16 727 250 9,3 10,5 +1,2 40 89 4 16 1 1 1425 342 7,3 9 +1,7 10 24 5 50 7 39 3968 860 8 10 +2 19 89 6 59 17 4 3100 290 7 11,6 +4,6 50 n.a. 7 39 10 5 2190 250 10,7 11,5 +0,8 46 48 8 38 3 18 1500 360 9 10,7 +1,7 12 45 9 16 1 9 2100 250 9 11,7 +2,7 13 52 Mean 37 6,1 14,1 1878 353 8 10 +2,2 26,6 58,1 Median 39 5 16 1500 290 9 10,7 +2 21 52 � Terminal complement inhibition by eculizumab in non transfused PNH patients leads to improvement of most clinical manifestations, including symptoms of intravascular hemolysis and anemia

16 39 events 3 events 14 Thrombosis Event Rate 12 P = 0.0001 (TE per 100 pt-years) 10 Normalized by time of 8 observation (pre and post) 6 4 ( n=195 ) ( n=195 ) 2 0 Pre-Eculizumab Treatment Eculizumab Treatment � 92% reduction in event rate with eculizumab Hillmen et al., Blood 2007

Blocking C5 Activity Lead to An Increase in Platelet Counts in Thrombocytopenic Patients Platelet count change in Platelet count in thrombocytopenic vs non- thrombocytopenic patients thrombocytopenic patients 100 25 Mean Platelet Counts (x10 9 /L) Mean Change in Platelets (x10 9 /L) 20 <100,000 90 >100,000 15 80 10 70 5 0 60 -5 50 -10 40 -15 -20 30 26 52 0 26 52 Eculizumab Treatment (Weeks) Eculizumab Treatment (Weeks) � Complement-mediated platelet consumption? � Possible relation with thrombophilia? Hill et al., ASH 2009

Haematologica. 2010 Apr;95(4):574-81. Epub 2010 Jan 15. Evaluation of hemostasis and endothelial function in patients with paroxysmal nocturnal hemoglobinuria receiving eculizumab. Helley D, de Latour RP, Porcher R, Rodrigues CA, Galy-Fauroux I, Matheron J, Duval A, Schved JF, Fischer AM, Socié G; French Society of Hematology. � Markers of thrombin generation and fibrinolisis decrease during eculizumab treatment � Markers of endothelial activation decrease during eculizumab treatment

NATURAL HISTORY OF PNH Overall survival by subcategory Increased mortality due to: – Thromboembolism – Severe marrow failure – (Clonal evolution to MDS/leukemia?) De Latour et al, Blood 2008

NATURAL HISTORY OF PNH Cumulative incidence of complications Thrombosis Cytopenia MDS/AML De Latour et al, Blood 2008

Br J Haematol. 2010 May;149(3):414-25. Epub 2010 Mar 8. Effect of eculizumab on haemolysis-associated nitric oxide depletion, dyspnoea, and measures of pulmonary hypertension in patients with paroxysmal nocturnal haemoglobinuria. Hill A, Rother RP, Wang X, Morris SM Jr, Quinn-Senger K, Kelly R, Richards SJ, Bessler M, Bell L, Hillmen P, Gladwin MT. Am J Hematol. 2010 Aug;85(8):553-9. Long-term effect of the complement inhibitor eculizumab on kidney function in patients with paroxysmal nocturnal hemoglobinuria. Hillmen P, Elebute M, Kelly R, Urbano-Ispizua A, Hill A, Rother RP, Khursigara G, Fu CL, Omine M, Browne P, Rosse W.

ECULIZUMAB AND PNH Indication to the treatment � Soliris TM is the first and only approved therapy for the treatment of hemolysis of transfusion-dependent PNH (USA March 2007, Europe June 2007) � In Italy, extended access program (law #648) for all PNH patients (even not transfusion dependent) with either: � Severe symptomatic intravascular hemolysis (frequent paroxisms, invalidating symptoms) � Overt life-threatening thromboembolism Caveat: Caveat: � Patients with concomitant aplastic anemia are very unlikely to respond

CLINICAL OVERLAP BETWEEN PNH AND BMF AA MDS? IMF? Hypoplastic Florid PNH Subclinical PNH in the PNH context of other AA/PNH PNH hematological disorders

ANTI-COMPLEMENT THERAPY AND PNH Reasons to treat all PNH patients (but not patients with PNH clone) � In almost all patients, optimal control of intravascular hemolysis, with: � Reduced transfusion requirement, improvement of anemia � Improved hemolysis-related symptoms and QoL � Marked reduction in thromboembolic risk � Improvement of markers of pulmonary hypertension and chronic kidney failure (clinically relevant?) � Possible effect on survival � No major safety concerns However: However: 1. Elevated cost 2. Life-long supportive treatment, without expected cure 3. No effect on underlying bone marrow failure 4. Minor hematological benefit (as Hb level) in many patients � Proven reasons and possible solutions

THE CLINICAL RESPONSE TO ECULIZUMAB The Italian experience Hematological response Hgb ≥ ≥ ≥ 11 ≥ >50% 7.3% 36.6% ≤ 50% ≤ ≤ ≤ 12.2% 8 ≤ ≤ Hgb < 11 ≤ ≤ 43.9% n = 41 • Normal or almost-normal LDH level in all patients • Persistent reticulocytosis in almost all patients Risitano et al , Blood 2009

C3 coating on RBCs from PNH patients on eculizumab Double color flow cytometry Anti CD59 PE Anti C3d FITC PNH on Untreated eculizumab PNH Risitano et al , Blood 2009

THE COMPLEMENT CASCADE REGULATION IN PNH CD55 CD55 CD59 Physiological C3 tick-over Alternative pathway C3 C5 Classical MAC C3b C6 C7 C8 C9 pathway + C3b C5b Lectin C5 Amplification pathway convertase loop C3b PNH RBCs MAC-mediated intravascular hemolysis

THE COMPLEMENT CASCADE REGULATION IN PNH CD55 CD55 Eculizumab Physiological C3 tick-over Alternative pathway C3 C5 Classical C3b pathway + C3b Lectin C5 Amplification pathway convertase loop C3b,iC3b,C3d C3 C3 C3 Spleen Liver RES macrophages PNH RBCs C3-mediated extravascular hemolysis Risitano et al, Blood 2009

In vivo RBC survival 51 Cr hepato-splenic uptake after RBC labeling 3000 2000 PNH #2 Excess count PNH #3 1000 Hemolytic anemia 0 control -500 0 192 480 96 288 384 Hours Spleen Liver Risitano et al, Blood 2009

SPLENECTOMY: THE PROOF OF PRINCIPLE Overcoming extravascolar hemolysis in PNH on eculizumab Transfusions 12,0 4000 3500 100 10,0 3000 8,0 80 % PNH RBC Hb g/dL 2500 LDH IU/L 60 6,0 2000 1500 4,0 40 1000 20 2,0 500 0 0,0 0 -100 -12 -1 1 3 5 7 9 13 Weeks from splenectomy Placebo Eculizumab Risitano et al, Blood 2008 Splenectomy