Fabry Disease: new therapies in 2019

1. Fabry Disease: new therapies in 2019 Dr. Michael L. West Division of Nephrology Department of Medicine Dalhousie University Halifax NS Canada mlwest@dal.ca

2. Fabry DiseaseOMIM #301500 Glycosphingolipid= Gb3

3. Most specific therapies in Fabry disease increase a-gal enzyme activity X DNA* Effects Protein/Enzyme activity Gene Therapy ERT, modified ERT, SRT, Chaperone

4. New Therapies Chaperone Modified ERT Substrate Reduction Therapy Gene Therapy

5. Migalastat Chaperone (Galafold™, Amicus) • oral every 2 days • licensed in Canada 2017 • well tolerated • no problems with infusion reactions, antibodies • decreased heart wall thickness in some after switched from ERT to Migalastat • Recent reports of clearing of cornea verticillata

6. Chaperone Therapy • promotes enzyme folding, pairing, processing in cell • prevents breakdown of misfolded mutant enzyme • results in increase in residual a-gal activity of >3% • useful for only certain α-gal A mutations Frustaci et al NEJM 2001;345:25-32

7. Issues with Migalastat Chaperone • reimbursed in almost all provinces in Canada • private insurance coverage • costly • must have mutation that is “amenable” to chaperone • only 25% Fabry patients in Canada eligible • must also meet Canadian Fabry treatment guidelines, same as for ERT • adults only

8. “Amenable” Mutations in Canada CFDI unpublished data 2018

9. Canadian Fabry Disease Initiative Registry 2019 • total number of active FD patients 429 M 133, F 271, C 23 • patients on specific therapy 226 (53%) M 110, F 116 • ERT 211 (94%) 135 α, 76 β • Chaperone 15 (6%) • Modified ERT (study) 2 • Gene therapy (±ERT) (study) 5 • SRT (study) 0 CFDI registry unpublished data Jan 2019

10. Ongoing Migalastat Studies (Amicus) • Migalastat registry to determine long term outcomes • Switch studies from ERT (Replagal, Fabrazyme) to Migalastat • Study of biomarkers in blood and urine to determine Migalastat effect • Study of Migalastat in children (no sites in Canada) Search clinicaltrials.gov Contact: Amicus Therapeutics Patient Advocacy 609-662-2000; clinicaltrials@amicusrx.com

11. Modified ERT-Pegunigalsidase (Protalix) • human α-galactosidase enzyme made in tobacco plant cells in laboratory • different structure; additional large sugars on surface • lasts 25x longer with higher levels in blood than current ERT • given iv 1 mg/kg every 2 weeks PRX-102 Image courtesy of Protalix

12. Modified ERT • Pegunigalsidase alfa (PRX-102) • more stable, may cause less antidrug antibodies, safe, effective, well tolerated • phase III studies in adults-Canada, US, EU, Aus • not licensed anywhere PRX-102 Image courtesy of Protalix

13. Pegunigalsidase alfa Longer half life and higher exposure compared to other ERT Plasma drug concentration vs. time T½: Approx. 80 hours pegunigalsidase alfa time frame agalsidase beta time frame T½ (Hours) * ** Up to 14 days AUC (0-∞): >35 fold from current ERTs Concentration (ng/mL) AUC (ug*min/mL) * *agalsidase beta – USPI ; ** agalsidase alfa -SMPC

14. Pegunigalsidase Results • BRIDGE study adults, prior ET agalsidase alfa x 2 yrs • 16 pts treated w pegunigalsidase 1 mg/kg iv every 2 wks • eGFR improved from -6.8 to +3.7 ml/min/1.73m2 • Preliminary data, of 16/22 subjects, unpublished

15. Ongoing Modified ERT Studies • BRIDGE-adults switched from Replagal to Pegunigalsidase every 2 wks iv • BALANCE-adults switched from Fabrazyme to Pegunigalsidase every 2 wks iv • BRIGHT-adults taking Pegunigalsidase double dose every 4 wks iv • BRILLIANCE-long term extension study 2 years • Halifax is only site in Canada

16. Substrate Reduction Therapy SRT • inhibitor of enzyme upstream from a-galactosidase • Shown to decreases build up of Gb3 • Lucerastat (Idorsia) • oral, well tolerated • Phase III study Fabry patients with neuropathic pain, switch from ERT to SRT • Canadian study sites Halifax, Winnipeg, Vancouver • Web site for prospective subjects https://www.modifyfabry.com

17. Substrate Reduction Therapy SRT • Gb3 A-galEnz Enz 1 GCS Enz 2 Storage Lucerastat-inhibitor of glucosylceramide synthase (GCS)

18. Substrate Reduction Therapy SRT A-galEnz • Gb3 Enz 1 GCS Enz 2 Storage SRT Lucerastat-inhibitor of glucosylceramide synthase (GCS)

19. Gene Therapy: how it works • virus is altered to carry human GLA gene; viral DNA removed • stem cells in test tube injected with DNA • stem cells infused back into patient • stem cells make and release a-gal enzyme throughout body + Stem cell Altered virus vector Gene therapy

20. Why Gene Therapy for Fabry Disease? • single gene defect • small DNA • mice created with gene therapy are healthy with >10,000-fold higher a-gal A activity

21. Why Gene Therapy for Fabry Disease? low levels of sustained enzyme activity may be more effective than a large intermittentinfusion i.e. ERT

22. Metabolic Cooperativity Model for Gene Therapy of LSDs Primary Producer Cell Secondary Recipient Cell Gene Transfer of the enzyme coding sequence Nucleus or Nucleus Overexpression of the lysosomal hydrolase Functional Correction of recipient cells TGN Man-6-P Receptors Lysosome Lysosome Uptake into uncorrected bystander cells Intracellular Correction of the enzymatic defect (ERT) Secretion of the lysosomal enzyme FACTs Project: FAbry Disease Clinical Research and Therapeutics

23. FACTS Study Lentivirus transduction in lab Collection of blood stem cells from patient Measure outcomes Infusion back into patient given low dose chemotherapy x1 FACTs Project: FAbry Disease Clinical Research and Therapeutics

24. FACTs Fabry Gene Therapy Trial: Long-term Outcome Measures • presence of viral vector with human DNA in cells of blood and bone marrow • increase in enzyme in blood • antibody responses • clonality of integration FACTs Project: FAbry Disease Clinical Research and Therapeutics

25. Additional Drug Regimen • Drug conditioning to make space in BM (melphalan 100 mg/m2 ivx1) • with metabolic cooperativity effects, do not need 100% donor cells transfected • out-patient procedure: well tolerated by Fabry patients FACTs Project: FAbry Disease Clinical Research and Therapeutics

26. FACTS study Nov. 2018: patient 4 during infusion of transduced cells in Halifax • Health Canada approval April 29, 2016 • 5 patients enrolled, last in Calgary Feb 2019 • Enrollment finished Permission was obtained to use patient image

27. FACTS Study • 5 adult males underwent SCT after LV/AGA treatment • monitor patients closely for adverse effects to determine safety • followed by Fabry specialist and bone marrow specialist for 5 years FACTs Project: FAbry Disease Clinical Research and Therapeutics

28. Jan 2017: patient 1 during infusion of transduced cells in Calgary What about ERT? • A-gal activity measured pre ERT so will reflect patient’s own residual enzyme activity • no ERT for 60 days, then resume • Can stop after 6 months if well, normal enzyme level • 2/3 pts so far have stopped ERT Permission has been obtained to use patient image FACTs Project: FAbry Disease Clinical Research and Therapeutics

29. Outcomes • Patients all feeling well • All with increased a-gal activity in plasma and white blood cells • All with new GLA gene present in their DNA in white blood cells FACTs Project: FAbry Disease Clinical Research and Therapeutics

30. Safety Adverse Events • none related to viral vector • transient low blood counts week 2 in all patients 3 patients: adverse effects related to protocol but not viral vector • fainting spell • bled into thigh with low platelet count • fever with low WBC, FACTs Project: FAbry Disease Clinical Research and Therapeutics

31. FACTs trial offers several firsts • first in the world Fabry disease gene therapy trial • first adult LV gene therapy trial in lysosomal diseases 1

32. Questions about Gene Therapy • How long can transduced stem cells live and function in the body? • Can stem cells make enough enzyme to keep patients healthy? • Is this procedure safe in the long term? • Will gene therapy cost less than ERT?

33. AvroBio gene study • based on same vector • 12 male Fabry patients ages 16-55; 2 done already • no prior ERT • kidney biopsies • Australia, USA, Calgary, Halifax in Canada

34. Other gene studies • AAV adeno-associated virus, iv infusion x1; targeted to liver cells, make enzyme, increase a-gal activity in kidney, heart and liver in Fabry mouse studies (Sangamo, USA), recruiting patients now • AAV8, similar study in mice w increased a-gal activity, decr GB3 in organs (Freeline, UK) • AAV targeted to heart, study in mice, monkeys, (4DMT, USA) • AAV9 study in mice, increased a-gal activity in organs (Niu, Taiwan) • mRNA iv, makes enzyme, study in mice (Moderna, USA)

35. New ERT Studies • Switch from chaperone Migalastat or Replagal ERT to Fabrazyme ERT (Sanofi-Genzyme) • Adult males on therapy <5 years • Kidney biopsy x 2 • ? any study sites in Canada

36. New ERT Studies • Replagal ERT increased dose (Takeda) • No details yet • ? any study sites in Canada

37. Comparison of New Therapies ADA antidrug antibodies; IAR infusion associated reactions

38. Fabry disease treatment studies 2019 Halifax gene therapy, SRT, modified ERT, chaperone Vancouver SRT Montreal chaperone Calgary gene therapy, SRT, chaperone Winnipeg SRT Toronto gene therapy

39. Conclusions • ERT and chaperone are only licensed therapies to date for Fabry disease in Canada • Still awaiting a cure • Many new therapies being developed: • modified ERT • substrate reduction therapy • gene therapy • other • Treatment and outcomes will only get betterwith studies of new agents