CURRENT AND FUTURE STRATEGIES FOR THE TREATMENT OF METABOLIC STORAGE DISORDERS

Roscoe O. Brady, M.D.

Chief, Developmental and MetabolicNeurology Branch

National Institute of NeurologicalDisorders and Stroke

National Institutes of Health

Bethesda, Maryland

CURRENT AND FUTURE STRATEGIES FOR THE

TREATMENT OF METABOLIC STORAGE DISORDERS

1. BONE MARROW TRANSPLANTATION

2. ENZYME REPLACEMENT THERAPY

3. SUBSTRATE REDUCTION THERAPY

4. MOLECULAR CHAPERONE THERAPY

5. GENE THERAPY

Hereditary Lipid Storage Disorders

Sphingolipidoses

SPHINGOSINE

CH3 -(CH2)12-CH=CH-CH-CH-CH2OH

OH NH2

Carbon atoms 1 and 2 arise from the amino acid serine

Carbon atoms 3 to 18 arise from palmitic acid

1318 2

CERAMIDE

Sphingosine

CH3 -(CH2)12-CH=CH-CH-CH-CH2OH

OH NH

CH3 - (CH2)22 - C = 0

Long Chain Fatty Acid

GAUCHER DISEASE

Gaucher DiseaseType 1

(Non-

Neuronopathic)

Enlargedliver Huge spleen

Easy bruisingdue to lowblood platelets

Anemia

Bone damage

ACCUMULATING LIPID IN GAUCHER DISEASE

GLUCOCEREBROSIDE

SPHINGOSINE GLUCOSE

FATTY ACID

ENZYMATIC DEFECT IN GAUCHER DISEASE

DEFICIENCY OF GLUCOCEREBROSIDASE

SPHINGOSINE GLUCOSE

FATTY ACID

R. O. Brady et al. Biochem Biophys Res Commun 1965; 18: 221

WHAT IS THE ORIGIN OF THE ACCUMULATING LIPID?

CERAMIDELACTOSIDE

SPHINGOSINE GLUCOSE GALACTOSE

FATTY ACID

MAJOR LIPID OF WHITE BLOOD CELLS

MAJOR LIPID OF RED BLOOD CELLS

GLOBOSIDE

SPHINGOSINE—GLUCOSE—GALACTOSE—GALACTOSE—N-ACETYGALACTOSAMINE

FATTY ACID

• 20-40 times more glucocerebroside arises from senescent

white blood cells than red blood cells

TREATMENT OF PATIENTS WITH

LYSOSOMAL STORAGE DISORDERS

1. Bone Marrow Transplantation

BONE MARROW TRANSPLANTATION (BMT)

If a suitable match is available, BMT can cure a

patient with type 1 Gaucher disease

Risks

Graft-versus host disease

Continuous immunosuppression probably necessary

Implication

? Gene therapy using transduced bone marrow stem cells

R. O. BRADY N Engl J Med 1966; 275: 312

TREATMENT STRATEGIES

2. ENZYME REPLACEMENT THERAPY

GAUCHER DISEASE

The required enzyme glucocerebrosidase is currently

produced recombinantly in Chinese hamster ovary cells.

It is necessary to modify the glycoform of this enzyme

in order to target it to macrophages, the principal lipid-

storing cells in the body of patients.

Amino Acid Chain

GLUCOCEREBROSIDASE IS TREATED WITH

3 EXOGLYCOSIDASES

Amino Acid Chain

Delivery of mannose-terminal glucocerebrosidase

to lipid-storing macrophages (Kupffer cells in the

liver) is increased 50-fold over that of unmodified

glucocerebrosidase

RESULTS OF ENZYME REPLACEMENT THERAPY

IN GAUCHER PATIENTS USING MACROPHAGE-

TARGETED GLUCOCEREBROSIDASE

Spleen size decreases Liver size decreases Hemoglobin increases Blood platelets increase Skeleton improves

MRI OF ABDOMEN

SPLEEN

ERT 7 months ERT

MORE THAN 4,300 PATIENTS WITH GAUCHER

DISEASE ARE NOW RECEIVING ENZYME

REPLACEMENT THERAPY

TYPE 2 GAUCHER DISEASE

Acute Neuronopathic Gaucher Disease

Neuronophagia in the brain of a patient with Type 2 Gaucher disease

WHAT IS THE SOURCE OF GLUCOCEREBROSIDE

IN THE BRAIN?

Ganglioside GDIa

SPHINGOSINE -GLUCOSE -GALACTOSE- N-ACETYGALACTOSAMINE- GALACTOSE

FATTY ACID N-ACETYLNEURAMINIC ACID N-ACETYLNEURAMINIC ACID

ENZYME REPLACEMENT THERAPY IN

PATIENTS WITH TYPE 2 GAUCHER DISEASE

No benefit of intravenous glucocerebrosidase on brain

WOULD DIRECT INTRACEREBRAL INJECTION OF GLUCOCEREBROSIDASE BE EFFECTIVE?

(CONVECTION-ENHANCED DELIVERY)

Safety and Distribution of Mannose-terminal

Glucocerebrosidase Injected into the Brain of Normal Rats

G.C. Zirzow et al. Neurochemical Res 1999; 24: 301

NEURONAL UPTAKE OF INTRA-CEREBRALLY

ADMINISTERED GLUCOCEREBROSIDASE

Safety Study of Intracerebrally Injected Glucocerebrosidase

in Non-human Primates

R. Lonser et al, Annals of Neurology 2005; 57: 543

TREATMENT STRATEGIES

3. SUBSTRATE REDUCTION THERAPY

REDUCE THE FORMATION OF GLUCOCEREBROSIDE

SPHINGOSINE + UDP–GLUCOSE SPHINGOSINE GLUCOSE + UDPFATTY ACID

FATTY ACID

UDP-GLUCOSE = URIDINE DIPHOSPHATE GLUCOSE

= SITE OF INHIBITION OF GLUCOSYLTRANSFERASE

Glucocerebroside

MIGLUSTAT

Small Molecule Inhibitor of Glucocerebroside Formation

SUBSTRATE DEPLETION

Miglustat OGT 918 (Zavesca) has been approved for the treatment of patients with type 1 Gaucher disease for whom enzyme replacement therapy is not appropriate.

(Cox T, Lachmann R, Hollak C, et al. Lancet 2000; 355: 1481)

Patient withType 3a ChronicNeuronopathicGaucher Disease

Slow horizontaleye movement

SUBSTRATE DEPLETION

• Ongoing NIH Investigation of OGT 918 in Patients with Type 3 (Chronic Neuronopathic) Gaucher Disease Who Also Receive Enzyme Replacement Therapy to Control the Systemic Manifestations of the Disease

TREATMENT STRATEGIES

4. MOLECULAR CHAPERONE THERAPY

GM1-GANGLIOSIDOSIS

Juvenile

Infantile

Chronic Adult Adult

GM1

Gangliosidosis Phenotypes

SPHINGOSINE-GLUCOSE-GALACTOSE-N-ACETYGALACTOSAMINE-GALACTOSE

FATTY ACID N-ACETYLNEURAMINIC ACID

Accumulation of Ganglioside GM1

SPHINGOSINE-GLUCOSE-GALACTOSE-N-ACETYGALACTOSAMINE-GALACTOSE

FATTY ACID N-ACETYLNEURAMINIC ACID

Enzymatic Defect in GM1-Gangliosidosis

-galactosidase deficiency

Okada and O’Brien 1968

CHEMICAL CHAPERONE THERAPY FOR BRAIN

PATHOLOGY IN GM1-GANGLIOSIDOSIS

CREATED A MOUSE MODEL WITH THE

JUVENILE PHENOTYPE OF GM1-

GANGLIOSIDOSIS BY CHANGING

ARGININE AT POSITION 201 OF

-GALACTOSIDASE TO CYSTEINE

(R201C)

N-0ctyl-4-epi--valienamine (NOEV)

Chemical Chaperone

J. Matsuda et al. Proc Natl Acad Sci USA 2003; 100: 15912

EFFECT OF N-OCTYL-4--VALIENAMINE (NOEV) ON -GALACTOSIDASE ACTIVITY IN CULTURED

MURINE FIBROBLASTS

Additions

None 0.2 M NOEV Fold

(nmols/h/mg protein)

Wild type 68 79 1.2

Juvenile GM1 23 116

5.1

REDUCTION OF GM1 IN THE BRAIN OF MICE

WITH THE JUVENILE PHENOTYPE OF GM1-

GANGLIOSIDOSIS WITH THE NOEV

CHAPERONE IN THE DRINKING WATER

Ganglioside GM1

? Chaperone Therapy for Gaucher Disease

N-Octyl--valienamine up-regulates activity of

F213I mutant -glucosidase in cultured cells:

a potential chemical chaperone therapy for

Gaucher disease.

Lin H, et al. Biochim Biophys Acta 2004; 1689: 219-228

FABRY DISEASE

CERAMIDETRIHEXOSIDE

SPHINGOSINE – GLUCOSE – GALACTOSE - GALACTOSE

FATTY ACID

PRINCIPAL ACCUMULATING LIPID IN FABRY DISEASE

CERAMIDETRIHEXOSIDASE

(Alpha-Galactosidase A)

SPHINGOSINE – GLUCOSE – GALACTOSE - GALACTOSE

FATTY ACID

ENZYMATIC DEFECT IN FABRY DISEASE

R. O. Brady et al New Engl J Med 1967

ENZYME REPLACEMENT THERAPY IN FABRY

PATIENTS HAS PRODUCED DISTINCT BENEFIT,

BUT NOT ALL OF THE MANIFESTATIONS ARE

COMPLETELY RESOLVED

MOLECULAR CHAPERONE THERAPY FOR

FABRY DISEASE

TREATMENT OF METABOLIC STORAGE DISORDERS

5. GENE THERAPY

1. GAUCHER DISEASE

Retroviral transduction of patients’ autologous bone-

marrow stem and progenitor cells -- 2 patients no clinical

benefit

2. FABRY DISEASE

Intravenous injection of adeno-associated virus with

human -galactosidase A gene into -galactosidase A

knock-out mice -- spectacular results - ?neoplasms

CURRENT AND FUTURE STRATEGIES FOR THE

TREATMENT OF METABOLIC STORAGE DISORDERS

1. BONE MARROW TRANSPLANTATION

2. ENZYME REPLACEMENT THERAPY

3. SUBSTRATE REDUCTION THERAPY

4. MOLECULAR CHAPERONE THERAPY

5. GENE THERAPY ?