sb-525, a novel gene therapy for treatment of … · preclinical and clinical studies • efficient...

SB-525, A NOVEL GENE THERAPY FOR TREATMENT OF HEMOPHILIA A

Kathleen Meyer MPH, PhD, DABT

Sangamo Therapeutics

NorCal SOT Meeting

October 24, 2019

We are committed to translating ground-breaking science into genomic medicines that transform patients’ lives

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Our capabilities allow us to design therapeutic approaches targeting the underlying genetic causes of disease

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Gene Therapy

Gene therapy provides tractable, valuable near-term

opportunities


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Gene Therapy Gene-EditedCell Therapy


opportunities

Continue to advance ex vivo editing to

create cell therapies

Ex Vivo


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Genome Editing Gene RegulationGene Therapy Gene-EditedCell Therapy

In Vivo


opportunities

Continue to advance ex vivo editing to

create cell therapies

Sustain momentum toward the long-term goal with in vivo gene editing and gene regulation

Ex Vivo

Sangamo’s genomic medicines encompass a breadth of technical approaches and diverse pipeline assets

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SB-525: Hemophilia AST-920: Fabry disease

Undisclosed targets

ST-400: Beta thalassemiaBIVV003: Sickle cell disease

TX200: Solid organ transplantKITE-037: Allo-CD19 CAR-T

Undisclosed targets

SB-913: MPS IISB-318: MPS I

SB-FIX: Hemophilia BUndisclosed targets

Genome Editing Gene Regulation

TauopathiesC9ORF72-linked ALS/FTLD

Huntington’s diseaseUndisclosed targets

Gene Therapy Gene-EditedCell Therapy

In VivoEx Vivo

Therapeutic Area Research Preclinical Phase I/II Phase III Collaborator

Gene Therapy

Hemophilia A (SB-525)

Fabry disease (ST-920)

Ex Vivo Gene-Edited Cell Therapy

Hemoglobinopathies (ST-400, BIVV003)

Solid organ transplant CAR-Treg (TX200)

Allogeneic anti-CD19 CAR-T (KITE-037)

In Vivo Genome Editing

MPS II (SB-913)

MPS I (SB-318)

Hemophilia B (SB-FIX)

In Vivo Gene Regulation

Tauopathies

ALS/FTLD - C9ORF72

Huntington’s Disease

Robust pipeline of genomic medicines in clinical and preclinical stages of development

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• Deficiency in FVIII clotting factor• Bleeding disorder occurring most often inside joints and

muscles• 70% of patients inherit Hemophilia A and 30%

develop spontaneous genetic mutation• Approximate incidence (CDC) 1 in 5,000 male births• 16,000 patients in US• 108,000 patients identified globally (WFH)• Average annual Hemophilia A treatment cost in

developed work $150 – 300K

Hemophilia A: chronic, disabling, painful and destructive disease

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.

FVIII and the coagulation cascade

Ther

apeu

tic V

alue

Evolution of Products

Evolution of hemophilia treatment

Recombinant Era

Improved Safety► Eliminated

potential for transmission of blood borne pathogens

Recombinant Clotting FactorsFVIII, FIX, FVIIa (1990s)

Plasma-DerivedClottingFactors(1969)

► Widespread viral contamination

► Biosimilars► Humanized► Prolonged half-life (FVIII/FIX)

EHL clotting factors (2014 - )

► Gene therapy► Novel agents

Investigational therapies(2015 – )

• Single gene disorder– Clear cause and effect relationship

• Replacement administration is demanding– Must be given 3x weekly iv

• Wide therapeutic window– Low levels will improve outcome– High levels welcome (up to a point)

• Efficacy easy to assess– Clinical– Laboratory

Why gene therapy for hemophilia?

SB-525

• Recombinant adeno-associated virus (AAV) has been used extensively for nearly 20 years as a gene therapy vector in preclinical and clinical studies

• Efficient transduction and long term, stable transgene expression in non-dividing cells such as liver, neurons and muscle

• Non-pathogenic, replication-deficient

• High degree of stability which allows for rigorous methods of vector purification

• AAV vectors carrying capacity is small (~4.7 kb of DNA)

• Composed of inverted terminal repeats (ITRs) flanking transgene construct

• SB-525 utilizes AAV2 ITRs and AAV6 capsid proteins

SB-525 for the treatment of adults with hemophilia A

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AAV2/6

• hF8 is not an ideal gene for AAV– Constrained by hF8 gene sizeo Optimal AAV transgene size is ~4.7 kg; full length hF8 is ~7kb

• AAV dose required to achieve therapeutic hFVIII levels• Shorter coding sequence for hF8• Optimized B-domain deleted sequence (BDD)• Optimized liver-specific promoter modules to drive hF8 expression• Improved virus yields

What is optimal for rAAV human F8 cDNA?

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Optimization of AAV hF8 cDNA required multi-factorial modifications

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PolyAhF8 B-domain deleted (BDD)ITR ITRLiver-specific promoter

Promoter module modifications

• Assembled different permutations of liver-specific promoter elements

• A systematic mutational design approach was used to improve regions of the promoter module

Transgene modifications

• Optimized the F8 cassette

Other modifications

• Identified minimal synthetic polyA

• Removed unnecessary nucleic acids to reduce size

• Optimized sequences outside transgene

hFVIII protein has the same amino acid sequence as biologics currently in clinic

SB-525 liver directed AAV6 hF8 cDNA gene therapy for hemophilia A

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P liver- specific promoterTG therapeutic gene (F8)

Transgene packaged into AAV vectors

Therapeutic delivered by a single infusion

Liver produces and secretes therapeutic hFVIII protein

AAV vectors

Liver Cell DNA

Promoter

TherapeuticGene (hF8)

Nucleus

Liver Cell

Transgene is expressed from the liver, but remains separate from the cell’s DNA

P TGtransgene

Transgene packaged into AAV vectors

AAV is delivered by a single infusion

AAV traffics to liver to deliver transgene into nucleus of liver cells

• Establishment of biological plausibility• Identification of biologically active dose levels• Selection of potential starting dose level, dose-escalation schedule and dosing

regimen for clinical studies• Establishment of feasibility and reasonable safety of product’s proposed

clinical route of administration• Support of patient eligibility criteria• Identification of physiological parameters that can guide clinical monitoring• Identification of potential public health risks

Objective of the nonclinical program

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• In vitro studies in primary human hepatocytes showing hFVIII production• 3-month pharmacology study in hemophilia A mice• 2-month pharmacology and toxicity study with highly related variant of

SB-525• 3-month GLP pharmacology, biodistribution and toxicity study in mice• 2-month pharmacology, biodistribution and toxicity study in cynomolgus

monkeys

Nonclinical studies supporting First-in-Human study

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Gene therapy FDA and EMA guidance documents

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• Hemophilia A mouse model to demonstrate SB-525 pharmacodynamic activity

• SB-525 IV dose of 7.2E+12 vg/kg

• Hemophilia A R593C mice are tolerized to hFVIII as they contain a hF8-R593C transgene under control of a mouse albumin promoter

• Human FVIII-R593C mutation is frequently found in Hemophilia A patients; in mice produces no detectable hFVIII protein

• Thought to be rapidly degraded in mice, with peptide fragments presented to the immune system

• Mice also contain a knockout of the mouse F8 gene and are deficient for endogenous mouse FVIII protein

SB-525 pharmacodynamic activity in hemophilia A mice

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70

Test articleinjection

14 21 28 days 3 months

Plasma collection schedule

Endpoint• Chromogenic assay for

hFVIII activity

• Tail vein transection (TVT) for hemostasis

Hemophilia A mouse model shows SB-525 functional impact

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TVT method based onJohansen et al., Haemophilia, 1-7, 2016

F o rm u la tio n S B -5 2 5 0

1 0

2 0

3 0

4 0

5 0

p < 0 .0 0 0 1

To

tal

Ble

ed

ing

Tim

e (

min

)

n o r m a l b le e d in g t im e

Bleed TimeTail Vein Transection (TVT)

F o rm u la tio n S B -5 2 5 0

2 0 0

4 0 0

6 0 0

hF

VII

I (P

erc

en

t N

orm

al)

458.1

hFVIII Activity

Activity determined by Chromogenic Activity Assay

• 2-month study in cynomolgus monkeys• SB-525 IV doses 2E+11 vg/kg to 6E+12

vg/kg• Pharmacodynamic endpoints• Biodistribution endpoints• Safety endpoints

SB-525 pharmacology and toxicology NHP study design

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70

Test articleinjection

14 21 28 days 56 days

Plasma collection schedule

Endpoints• ELISA for hFVIII levels• qRT-PCR for hF8 mRNA • Biodistribution• Safety assessment

Immunosuppression (IS) regiment of rituximab and steroids; early and late IS regiment

SB-525 NHP data – h8 mRNA expression restricted to liver

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hF8 mRNA (qRT-PCR)

L ive r

H e a r t

K idn e y

B rain

(FC )

B rain

(Ce r )

S p lee n

T e s tes

L u n g0

5

1 0

1 5

2 0

2 5

Re

lati

ve

No

rma

lize

d E

xp

res

sio

n

Restricted hF8 mRNA liver expression; identical results observed in mice

6 E + 1 1 9 E + 1 1 2 E + 1 2 6 E + 1 2 0 .1

1

1 0

1 0 0

D o s e (v g /k g )

Re

lati

ve

No

rma

lize

d E

xp

res

sio

n

L e f t L a te ra l L iv e r L o b e

6 E + 1 1 9 E + 1 1 2 E + 1 2 6 E + 1 2 0 .1

1

1 0

1 0 0

D o s e (v g /k g )

Re

lati

ve

No

rma

lize

d E

xp

res

sio

n

R ig h t L a te ra l L iv e r L o b e

6 E + 1 1 9 E + 1 1 2 E + 1 2 6 E + 1 2 0 .1

1

1 0

1 0 0

D o s e (v g /k g )

Re

lati

ve

No

rma

lize

d E

xp

res

sio

n

L e f t M e d ia l L iv e r L o b e

6 E + 1 1 9 E + 1 1 2 E + 1 2 6 E + 1 2 0 .1

1

1 0

1 0 0

D o s e (v g /k g )

Re

lati

ve

No

rma

lize

d E

xp

res

sio

n

R ig h t M e d ia l L iv e r L o b e

6 E + 1 1 9 E + 1 1 2 E + 1 2 6 E + 1 2 0 .1

1

1 0

1 0 0

D o s e (v g /k g )

Re

lati

ve

No

rma

lize

d E

xp

res

sio

n

C a u d a te L iv e r L o b e

Uniform hF8 mRNA distribution across liver lobes

SB-525 dose response supports clinical dose selection

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2 E + 1 1 6 E + 1 1 9 E + 1 1 2 E + 1 2 6 E + 1 21

1 0

1 0 0

1 0 0 0

T o ta l D o s e (v g /k g )

hF

VII

I (P

erc

en

t N

orm

al)

5 6 .4

2 27 .9

6 .41 1 .7

3 .9

Therapeutic levels of hFVIII (> 5% of normal) support starting clinical doses in the E11 vg/kg range

NHP Data – kinetics of hFVIII expression, peak levels Day 7-14

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Plasma hFVIII Levels

G ro u p 56 E + 1 2 v g /k g

- 2 0 0 2 0 4 0 6 00

5 0

1 0 0

1 5 0

2 0 0

2 5 0

3 0 0

3 5 0

D a y s P o s t D o s in g

hF

VIII

(P

erce

nt

No

rmal

)

A n im a l 2 2 h F V III



G ro u p 42 E + 1 2 v g /k g

- 2 0 0 2 0 4 0 6 00

2 0

4 0

6 0

8 0

D a y s P o s t D o s in g

hF

VIII

(P

erce

nt

No

rmal

)




SB-525 safety - summary of liver biodistribution and histopathology

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Strain/Species

Highest AAVDose (vg/kg)

Duration(months)

Immuno-suppression

ALT/ASTLevels

Biodistribution/Shedding

End of Study

Liver HistopathologyEnd of Study

C57BL/6 /Mouse GLP Study

2E+13 1, 2, 3 No Normal

• VGs highly liver-trophic, none detected in brain/testes

• No VGs detected in urine, saliva, feces, semen

No signs of hepatocellular hyperplasia, tumors or toxicity

Hemophilia A (hFVIII-R593C) / Mouse

2E+13 2 No Not Done • Not DoneNo signs of hepatocellular hyperplasia, tumors or toxicity

CynomolgusMonkey(highly related variant)

6E+12 8-9 Yes Normal• VGs highly liver-trophic, none detected in

brain/testesNo signs of hepatocellular hyperplasia, tumors or toxicity

CynomolgusMonkey 6E+12

3 Yes Normal

• VGs highly liver-trophic, none detected in brain/testes

• No VGs detected in urine, saliva, feces in high dose group after 4 days

No signs of hepatocellular hyperplasia, tumors or toxicity

SB-525, gene therapy for hemophilia A

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Goals

• Orphan Drug• Fast Track• RMAT

IND open• Orphan Medicinal Product

Patient safety FVIII activity Reduction of bleeding events

Reduction of factor replacement use

Phase I/II Open Label Study (ALTA)

Dose Escalation Complete

Cohort 3Cohort 1 Cohort 2 Cohort 4 • Enrollment complete• Updated results presented at ISTH

Next stepsOngoing Phase I/II Study

9e11 vg/kg 2e12 vg/kg 1e13 vg/kg 3e13 vg/kg(Patients did not receive prophylactic steroids)

• Present follow-up patient data in 4Q 2019• Complete transfer of manufacturing to Pfizer• Regulatory discussions underway for Phase III

Factor VIII activity: chromogenic assay

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Konkle BA et al. ISTH 2019 Melbourne, AU, 6 July 2019

Study Week0 10 20 30 40 50 60 0 10 20 30 40 50 60

Study Week

250

200

150

100

50

0

100

10

1

LogarithmicLinearSubject 4 (2e12 vg/kg)Subject 5 (1e13 vg/kg)Subject 6 (1e13 vg/kg)Subject 7 (3e13 vg/kg)Subject 8 (3e13 vg/kg)Subject 9 (3e13 vg/kg)Subject 10 (3e13 vg/kg)

Moderate (1-5%)

Normal (50-170%)

Mild (6-49%)

Fact

or V

III A

ctiv

ity (I

U/d

L)

* Subsequent to the data cut used for the ISTH presentation, Subject 9 attained normal levels at week 7

*

*

Factor VIII activity: chromogenic, Cohort 4 (3e13 vg/kg)

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Fact

or V

III A

ctiv

ity (I

U/d

L)

100

10


Logarithmic

5 10 15 20 25Study Week

Subject 7 (week 24)Subject 8 (week 19)Subject 9 (week 6)Subject 10 (week 4)

Normal (50-170%)

Mild (6-49%)

*

* Subsequent to the data cut used for the ISTH presentation, Subject 9 attained normal levels at week 7

Spontaneous bleeding episodes

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Dose Cohort(dose vg/kg)

1 (9e11) 1 93 7

1 (9e11) 2 83 5

2 (2e12) 3 73 8

2 (2e12) 4 66 5

3 (1e13) 5 50 5

3 (1e13) 6 41 0

4 (3e13) 7 24 0

4 (3e13) 8 18 0

4 (3e13) 9 5 0

4 (3e13) 10 2 n/a*

Subject Follow-Up (weeks)

Bleeding Episodes≥3 weeks

Post Treatment

Konkle BA et al. ISTH 2019 Melbourne, AU, 6 July 2019Data cut-off date: 30 MAY 2019

*n/a: < 3 weeks of follow-up at time of data cut

Factor VIII replacement usage

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Dose Cohort(dose vg/kg)

1 (9e11) 1 93 2/Week 115

1 (9e11) 2 83 2/Week 26

2 (2e12) 3 73 2/Week 13

2 (2e12) 4 66 3/Week 9

3 (1e13) 5 50 Every Other Day 11

3 (1e13) 6 41 Every Other Day 0

4 (3e13) 7 24 Every 4 Days 0

4 (3e13) 8 18 Every Other Day 1*

4 (3e13) 9 5 Every 3 Days 0

4 (3e13) 10 2 Every 3 Days n/a§

Subject Follow-Up (weeks)

Factor VIII Prophylactic

RegimenPrior to Dosing

Factor VIII Infusions≥ 3 weeks

Following SB-525 Treatment

*Prophylactic coverage stopped 3 weeks and 2 days after SB-525 administration, §n/a: < 3 weeks of follow-up at time of data cut


Treatment-related adverse event (TRAE) summary

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N= Total number of subjects in each treatment group, n= number of subjects in each system organ class (SOC), [T]= total number of treatment-related adverse events. *All 3 events were reported as Grade 2 ** Grade 3 event reported.

MedDRA Preferred Term

Any treatment-related event 0 2 (100) [4] 0 3 (75) [8] 5 (50) [12]

Alanine aminotransferase increased 0 2 (100) [3] 0 1 (25) [1] 3 (30) [4]

Pyrexia 0 0 0 3 (75) [3]* 3 (30) [3]

Aspartate aminotransferase increased 0 1 (50) [1] 0 0 1 (10) [1]

Fatigue 0 0 0 1 (25) [1] 1 (10) [1]

Hypotension 0 0 0 1 (25) [1]** 1 (10) [1]

Myalgia 0 0 0 1 (25) [1] 1 (10) [1]

Tachycardia 0 0 0 1 (25) [1] 1 (10) [1]

Cohort 19e11 vg/kg

(N=2)n(%)[T]

Cohort 22e12 vg/kg

(N=2)n(%)[T]

Cohort 31e13 vg/kg

(N=2)n(%)[T]

Cohort 43e13 vg/kg

(N=4)n(%)[T]

Overall(N=10)

n(%)[T]


● Treatment-related SAEs of hypotension (grade 3) and fever (grade 2) in one Cohort 4 subject occurred 6 hrs following SB-525 infusion. Fully resolved with treatment within 24 hrs

o Based on the temporal association, assessed as related to study treatment o No similar hypotension observed in subsequent 3 subjects dosed

● In the 3e13 vg/kg cohort two subjects experienced a transient grade 1 alanine aminotransferase elevation (>1.5 x baseline) managed with a tapering course of oral steroids. Neither resulted in a loss of FVIII activity levels

Safety summary

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Data cut-off date: 30 MAY 2019

Acknowledgements

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• Liching Cao

• Mubarack Muthalif

• Judy Greengard

• Annemarie Ledeboer

• Lisa King

• Stephen Ballaron

• Daniel Richards

• Melanie Butler

• Carolyn Gasper

• Kathy Meyer

• Dale Ando

• Didier Rouy

• Nathalie Dubois-Stringfellow

• Our clinical trial subjects, families and physicians

• Brigit Riley

• Mike Holmes

• Jeff Boonsripisal

• Derek Liu

• Rainier Amora

• Lei Zhang

• Jianbin Wang

• Susan Abrahamson

• Richard Surosky

• Alicia Goodwin

• Andrea Kang

• Tim Gabriele

• Hung Tran

• Jennifer Huang

• David Lillicrap

• Christine Hough

• Dominique Cartier

• Kate Nesbitt

• Courtney Dwyer

• Kassandra Herbert

sb-525, a novel gene therapy for treatment of … · preclinical and clinical studies • efficient...

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