1. FDA Review of Clinical Data Agalsidase alfa for treatment of Fabry Disease Transkaryotic Therapies, Inc. FDA/Center for Biologics Evaluation and Research

2. Agalsidase alfaIntroduction Proposed indication: “Replagal is indicated for long-term enzyme replacement therapy for patients with Fabry Disease (  -galactosidase A deficiency)” Proposed dose: 0.2 mg/kg IV every 2 weeks

3. Agalsidase alfaOverview of Studies Studies submitted to BLA: StudyCountryDesignn 001USASingle dose/dose escalation10 003USAPlacebo-controlled26 006USANoncontrolled, post 00325 011USANoncontrolled, post 00624 005UKPlacebo-controlled15 014GermanyNoncontrolled15

4. Agalsidase alfaOverview Notable observations:  Pain outcomes  Renal function  Renal histopathology  Cardiac outcomes  Weight changes  Antibody formation  Safety findings

5. Agalsidase alfaStudy 003 Design Study 003 design:  Single center, randomized, double-blind, placebo-controlled, six months  26 Men with neuropathic pain  Evaluations  Pain scores, renal biopsy, cardiac data  Primary EP: “Worst Pain” score while “off pain medication”  Many 2 ⁰ and 3 ⁰ EP

6. Agalsidase alfa Study 003 Design Analytic Plan  Primary endpoint: T-test comparison of area under the curve of pain score change from baseline for the four “off pain medication” assessments  Numerous exploratory analyses:  Repeated measures analysis  Analyses of all pain assessments (on and off pain medication; RM & AUC)  Missing value imputations

7. Agalsidase alfa Study 003 Results Primary endpoint result: Agalsidase n = 14 m ± se Placebo n = 12 m ± se AUC- 22 ± 9- 1 ± 14 P-value 0.20

8. Agalsidase alfa Study 003 Results Limitations to “off medication” analyses:  Inability to verify medication use status at the time of pain score assessment  Definition of “pain medication” highly problematic  Distinguished between types of analgesics  Common analgesics (e.g. NSAID, opiates) treated as ineffective on Fabry pain

9. Agalsidase alfa Study 003 Results  Additional pain outcomes and exploratory analyses Other prospective planned analytic methods (repeated measures) and analyses of all pain assessments (mixed on and “off” medication; AUC or RM analyses) generally provide no support for a finding of efficacy in the reduction of pain.

10. Agalsidase alfa Study 003 Results  Study 003 Pain endpoint findings: Primary endpoint data cannot be interpreted due to inability to verify pain medication usage and a problematic definition of “pain medication.” Exploratory and additional pain data analyses also provide no evidence for a treatment effect.

11. Agalsidase alfa Renal Function AgalsidasePlaceboP-value Ch to Wk 240- 200.05 Ch to Wk 234- 20.54 Study 003 Average Cr Cl Change (mL/min)

12. Agalsidase alfa Renal Function Study 003 Serum Cr (mg/dL) & Cr Cl (mL/min) AgalsidasePlacebo CrCr ClCrCr Cl Baseline1.01031.3103 Week 231.11071.9101 Week 241.11031.985

13. Agalsidase alfa Renal Function Creatinine clearance

14. Agalsidase alfa Renal Function StudyAgalsidasePlaceboP-value 003- 9- 200.65 00525140.34 Average GFR Change (mL/min)

15. Agalsidase alfa Renal Function GFR

16. Agalsidase alfa Renal Function Renal function in noncontrolled studies show no change in: Cr Cl GFR

17. Agalsidase alfa Renal Function Historical Assessment of Renal Deterioration Datan Rate of decline (mL/min/yr) Literature review1121 Branton et al.1412.2 003 Placebo subjects1125 Summary3618.7 Average age of 38 years for onset of ESRD from literature review of 363 subjects Average age of 34.5 at enrollment in Study 003

18. Agalsidase alfa Renal Function Limitations of Historical Assessment of Renal Deterioration:  Small sample size  Published data are from subjects with marked renal insufficiency at baseline

19. Agalsidase alfa Histopathology Renal histopathology:  Data:  Paired samples for 21 subjects  Missing samples for 5 subjects: Agalsidase n = 2, Placebo n = 3  Analyses:  Acute Lipid Damage Score (ALDS)  Chronic Damage Score (CDS)  Standard Histopathology

20. Agalsidase alfa Histopathology Average ALDS score Agalsidase n = 11 Placebo n = 9 P-value Baseline98n/a Wk 24 Change - 210.11

21. Agalsidase alfa Histopathology ALDS Components Change in: Agalsidase n = 11 m ± se Placebo n = 9 m ± se P-value Endocapillary cells- 0.7 ± 0.20.0 ± 0.30.04 Vascular endothelium- 1.2 ± 0.30.2 ± 0.3< 0.01 Glomerular epithelial cells 0.0 ± 0.3 0.83 Proximal tubules- 0.1 ± 0.10.1 ± 0.10.31 Distal tubules0.2 ± 0.40.0 ± 0.20.72 Vascular media0.0 ± 0.20.2 ± 0.40.80

22. Agalsidase alfa Histopathology Standard Histopathology Change in fraction of glomeruli with: Agalsidase n = 12 m ± se Placebo n = 9 m ± se P-value Normal appearance 0.08 ± 0.04- 0.16 ± 0.080.01 Mesangial widening - 0.13 ± 0.05 0.17 ± 0.080.01 Segmental sclerosis 0.04 ± 0.02- 0.03 ± 0.020.05 Obsolescence 0.00 ± 0.05 0.02 ± 0.030.87

23. Agalsidase alfa Histopathology Renal histopathology limitations:  Unclear clinical correlation  Limited rigor:  Criteria for “severity” of deposition  Criteria for glomerular category  Training of pathologists  Number of slides/stains/glomeruli reviewed  Source documents unavailable

24. Agalsidase alfa Cardiac Outcomes Study 005 design:  Single center, randomized, double-blind, placebo-controlled, six months  15 men with left ventricular enlargement on echo  Cardiac biopsy, MRI, echo, EKG  Primary endpoint: Cardiac Gb 3

25. Agalsidase alfa Cardiac Outcomes Study 005 primary endpoint: Change to: Agalsidase n = 6 m ± se Placebo n = 8 m ± se P-value Week 13- 0.0 ± 0.10.1 ± 0.10.73 Week 24- 0.1 ± 0.20.1 ± 0.10.42 Change from baseline in cardiac Gb 3 content (nmol/mcg protein)

26. Agalsidase alfa Cardiac Outcomes Other cardiac outcomes: LV mass by MRI and Echo Electrocardiographic changes  Study 005  Study 003  Noncontrolled studies

27. Agalsidase alfa Cardiac Outcomes MRI LV Mass, Study 005, Change: Agalsidase m ± se Placebo m ± se P-value LV M ITT (gm) - 12 ± 11 n = 7 11 ± 12 n = 8 0.10 LV M Subset (gm) - 12 ± 11 n = 7 22 ± 6 n = 7 0.04 LV P Wall (mm) 0.7 ± 0.4 n = 7 0.6 ± 0.6 n = 7 0.95

28. Agalsidase alfa Cardiac Outcomes Echo LV Mass, Study 005, Change : Agalsidase n = 7 m ± se Placebo n = 8 m ± se P-value Mass (g) - 20 ± 2722 ± 200.26 Mass Index (g/m 2 ) 4 ± 2640 ± 280.66 LV P Wall (mm) - 0.7 ± 1.01.0 ± 0.50.15

29. Agalsidase alfa Cardiac Outcomes LV mass findings, Study 003, Change : MeasureAgalsidase n = 14 Placebo n = 11 P-value MRI (g) 4 ± 34 ± 60.93 Echo (g/m 2 ) 14 ± 4- 8 ± 130.06 Similar findings in subset of subjects with LV enlargement, Agalsidase n = 7, Placebo n = 6

30. Agalsidase alfa Cardiac Outcomes Study 006 LV mass Prior AgalsidasePrior Placebo MRI (g) - 22 ± 5 n = 14 - 28 ± 10 n = 10 Echo (g/m 2 ) 7 ± 11 n = 12 28 ± 43 n = 7 Study 014 LV mass Subjects completing 6 months Echo (g/m 2 )- 23 ± 6 n = 11

31. Agalsidase alfa Cardiac Outcomes QRS duration in Study 005: QRS duration in Study 003: Agalsidase n = 7 m ± se Placebo n = 8 m ± se P-value Change (msec)- 12.9 ± 11.74.6 ± 1.90.81 Agalsidase n = 14* m ± se Placebo n = 12 m ± se P-value Change (msec)- 2.4 ± 3.93.6 ± 1.20.05 *one subject with intermittent BBB, baseline = 150 or 103 msec

32. Agalsidase alfa Cardiac Outcomes Study 006No change from baseline 014 Duration at week 27 only QRS Changes in Noncontrolled Studies

33. Agalsidase alfa Weight Weight changes in controlled studies: Study Change (kg) P-value AgalsidasePlacebo 003 1.6 ± 0.6 n = 13 - 1.4 ± 1.3 n = 10 0.03 005 0.7 ± 0.7 n = 7 1.3 ± 0.5 n = 8 0.33

34. Agalsidase alfa Weight Weight changes in noncontrolled studies:  Two years of follow-up, Study 006 & 011: Prior Agalsidase group ~ 2.1 kg (n = 12) Prior Placebo group ~ 2.7 kg (n = 9)  Six months follow-up in Study 014: Weight gain of ~ 0.9 kg (n = 11)

35. Agalsidase alfa Weight Limitations of weight data:  Concomitant medication  steroids  diuretics  Unclear nutritional status  Average baseline weights in controlled studies ~ 70 kg

36. Agalsidase alfa Antibody Antibody formation in Study 003:  50% to 64%, depending on assay ( ELISA, immunoprecipitation, neutralization) Antibody formation (ELISA) during 003, 006, 011 time periods:  13/25 (52%) positive at some point  3/13 had reversion to baseline levels  10 had persistently positive levels -- 7 had increasing magnitude

37. Agalsidase alfa Antibody Impact Plasma Gb 3 Concentration Among Subjects Completing Study 011 Interim

38. Agalsidase alfa Antibody Impact Urine Gb 3 Content Among Subjects Completing Study 011 Interim

39. Agalsidase alfa Safety Safety findings  No anaphylaxis  Infusion reactions  ~ 60 % in 003  ~ 40 % in 006  ~ 25 % in 011  Two infusion reaction SAE

40. Agalsidase alfa Overall Summary Multi-dose studies:  47 Adult Fabry Disease subjects infused with Agalsidase at 0.2 mg/kg on alternate weeks

41. Agalsidase alfa Overall Summary Controlled studies:  Study 003 (pain)  1  endpoint uninterpretable  Renal, cardiac, safety data  Study 005 (cardiac)  1  endpoint: no statistical difference between treatment groups in cardiac Gb 3 content  Renal, safety data

42. Agalsidase alfa Overall Summary Major observations from studies:  Renal function  Renal histopathology  Cardiac outcomes  Weight changes  Antibody formation  Infusion reactions

43. Agalsidase alfa Overall Summary Renal Function in controlled studies:  Cr Cl:  Study 003—Wk 23/24 inconsistent  Study 005—uninterpretable  GFR:  Study 003—no difference  Study 005—no difference

44. Agalsidase alfa Overall Summary Renal function in noncontrolled studies:  GFR and CC generally unchanged over 0.5 – 2.5 years Limitations in historical review of renal function changes over time preclude meaningful comparisons to noncontrolled clinical findings

45. Agalsidase alfa Overall Summary Renal histopathology:  Vascular Gb 3 deposition  Standard histopathology:  Agalsidase : fraction normal glomeruli fraction glomeruli with mesangial widening  Placebo : fraction glomeruli with segmental sclerosis

46. Agalsidase alfa Overall Summary Cardiac outcomes: StudyMRIEcho 005 in AgalNo difference 003No difference LV Mass in Controlled Studies

47. Agalsidase alfa Overall Summary Cardiac outcomes: QRS Changes in Controlled Studies Study 003 Duration with Agalsidase 005No difference

48. Agalsidase alfa Overall Summary Weight changes:  Study 003:  Agalsidase group gain, p = 0.03  Study 005:  No statistical difference  Study 006 & 011:  Gain of 2.1 – 2.7 kg over 2 yrs

49. Agalsidase alfa Overall Summary Infusion reactions:  ~ 60% in Study 003, lower in subsequent studies  Most mild – moderate severity Antibody formation:  ~ 30% have persistent antibody formation  Antibodies impact biomarkers