1. Gaucher Disease: Problems, Solutions, and Problems Seymour Packman, MD Department of Pediatrics Division of Medical Genetics Institute for Human Genetics University of California San Francisco

3. Gaucher Disease Type 1: Pathophysiology Deficiency of the lysosomal enzyme acid β- glucosidase Storage of glucosylceramide primarily in cells of the monocyte/macrophage lineage Progressive, multi-organ dysfunction primarily involving the reticulo- endothelial system Gaucher Cell Grabowski et al. MMBID Online. 2013. GMRB-0125-01

4. Clinical Manifestations of Gaucher Disease Type 1 Massive splenomegaly Cytopenia Hypermetabolic state: fatigue Infiltrative lung disease Avascular osteonecrosis Osteoporosis Pathological fractures Chronic bone pain Hepatomegaly Marrow infiltration Cytopenia Reflect Cellular Sites of Substrate Accumulation Grabowski et al. MMBID Online. 2010. Lung Alveolar macrophages Spleen Tissue macrophages Osteoclasts Bone Liver Kupffer cells (Hepatocytes spared) Bone marrow Monocytes Macrophages

5. Gaucher Clinical Presentation Charrow J et al., Arch Intern Med. 2000;160:2835. Clinical Involvement Patients with GD1 can present with any of these symptoms. Some may be severe and others completely absent. Pathologic fracture (15%) Osteonecrosis (25%) Osteopenia (42%) Anemia (64%) Thrombocytopenia (56%) Erlenmeyer flask deformity (46%) Hepatomegaly (79%) Splenomegaly (87%) Bone pain (63%) Bone crisis (33%) Joint collapse (8%) General symptoms: Fatigue Easy bruising/bleeding Menorraghia Decreased appetite Abdominal pain Bone marrow infiltration (40%) GMRB-0125-01

6. Milestones in Gaucher Disease Treatment 199020002010 1985: Glucocerebrosidase gene (GCB) cloned 1 and mapped to chromosome 1q21 1,2 First recombinant human glucocerebrosidase ERT approved in US (Cerezyme ® ) in 1994 and in EU in 1997 1991: First placental-derived glucocerebrosidase ERT approved in US and EU (Ceredase ® ) 1983: First patient with GD1 treated at NIH with glucocerebrosidase purified from human placenta 2011: Placebo- controlled trial of eliglustat completed in treatment-naïve GD1 patients 2012 1980 2003: IND filed for GZ- 112638 (eliglustat) 2003: First SRT approved in patients with GD1 for whom ERT is not an option (Zavesca ® ) IND=Investigational New Drug; ERT= enzyme replacement therapy; GD1=Gaucher disease type 1 1. Sorge. PNAS, 1985:82:7289; 2. Ginns, PNAS 1985;82:7101.

7. Approved Treatments for Gaucher Disease – Alglucerase (Ceredase ® ); purified human placental enzyme. Approved in 1991; no longer available – Imiglucerase (Cerezyme ® ); recombinant human enzyme; produced in CHO cells. Approved in 1994. – Velaglucerase alfa (Vpriv ®, Shire); recombinant human enzyme, produced in human cells. Approved in 2010. – Taliglucerase alfa (Elelyso TM, Pfizer/Protalix), recombinant human enzyme, produced in carrot cells Approved in 2012 GMRB-0125-01

8. ENZYME REPLACEMENT THERAPY Replacement of defective enzyme with normal genetically engineered enzyme Engineered enzyme is tagged with a specific recognition signal for delivery to appropriate cell or organelle Administration by intermittent IV

9. Rough ER P Cis Golgi P Trans Golgi Lysosome P Mannose-6-Phosphate Receptor System P = Mannose-6-P

10. GAUCHER DISEASE Enzyme Replacement Therapy  hemoglobin in a few months  platelets  organomegaly in ~ 6 months  bone pain, bone crises Slow change of bone X-ray abnormalities

16. Approved Treatments for Gaucher Disease Substrate reduction therapy (SRT); oral administration – Zavesca ® (miglustat, Actelion); imino sugar-based analogue Approved in 2003. Indicated only for adults with mild to moderate Gaucher disease who are unable or unwilling to receive ERT – Cerdelga ® (eliglustat, Genzyme); ceremide-based analogue Approved in 2014 Indicated for the longterm treatment of adult patients with Gaucher disease type 1 who are CYP2D6 extensive metabolizers (EMs), intermediate metabolizers (IMs), or poor metabolizers (PMs) as detected by a genetic test GMRB-0125-01

17. Synthesis (S) & Degradation (D) of glucosylceramide (GL-1) Normal Gaucher Gaucher Disease + ERT + SRT SDSSSDDD For graphic illustration purposes only. ERT=enzyme replacement therapy; SRT=substrate reduction therapy. Shayman. Drugs Future. 2010:35:613. Restoring a Balance Between GL-1 Substrate Synthesis and Degradation

20. Zavesca (miglustat) Effective in Gaucher treatment FDA approved if cannot use ERT Adverse reactions: - peripheral neuropathy (tingling, numbness, burning) - tremor (30%) - diarrhea (85%; reduce high CHO) - mild weight loss (65%)

21. miglustat

22. Eliglustat (Cerdelga) Mechanism of Action Glucosylceramide Synthase Acid β -glucosidase Deficient in Gaucher disease Eliglustat Ceramide + GlucoseGlucosylceramide Enzyme Replacement Therapy Shayman. Drugs Future. 2010:35:613. GMRB-0125-01

23. Ver. 10 May2010 23 Eliglustat Tartrate is a Novel Analog of Glucosylceramide GlucosylceramideEliglustat tartrate OH HN O O HO OH O HO N O O O HN OH

24. Inhibitors of Glucosylceramide Synthase GMRB-0125-01

25. Rough ER P Cis Golgi P Trans Golgi Lysosome P Mannose-6-Phosphate Receptor System P = Mannose-6-P

26. Chaperones

28. SMALL MOLECULES: CHAPERONES Stabilize mutant enzyme Increase β-glucocerebrosidase levels in Gaucher patients’ cells In development for Gaucher In phase III clinical trial for other lysosomal disorders

29. TREATMENT APPROACHES for LYSOSOMAL DISORDERS Enzyme replacement Novel biochemical measures – substrate reduction – chaperones – other small molecules: regulate gene expression or protein function; encapsulated cells

30. …out of nature’s certain course, A gift that rather was come late than soon. W. Wordsworth