Sandro Rusconi (09.03.52)Sandro Rusconi (09.03.52)UNIFRRusconi

2005

UNIFRRusconi

2005

What have we learned from 15 years in gene

therapy?

Sept 08, 2005GTRV Debio

1972-75 School teacher (Locarno, Switzerland)

1975-79 Graduation in Biology UNI Zuerich, Switzerland

1979-82 PhD curriculum UNI Zuerich, molecular biology

1982-84 Research assistant UNI Zuerich

1984-86 Postdoc UCSF, K Yamamoto, (San Francisco)

1987-93 Principal Investigator, UNI Zuerich, PD

1994-today Professor Biochemistry UNI Fribourg

1996-2002 Director Swiss National Research Program 37

'Somatic Gene Therapy'

2002-03 Sabbatical, Tufts Med. School Boston andUniv. Milano, Pharmacology Department

2002-05 President Union of Swiss Societies for

Experimental Biology (USGEB)

2002-06 Euregenethy Network (EU-harmonsiation of

biosafety and ethical aspects in gene therapy)

2005-xx Director of governmental division for cultureand university affairs of Canton Ticino

Gene therapy: A 15-years hailstorm of highly emotionalised good and bad news

Gene therapy: A 15-years hailstorm of highly emotionalised good and bad news

UNIFRRusconi

2005

UNIFRRusconi

2005

BBC, NBC, CNN,...

New York TimesWashington PostTimesLe MondeFrankfurter Allgemeine...

Feb 1990 First trial ADA deficiency

Dec 1988 IL-2 cancer treatment trial

Mar 1994 SAE cystic fibrosis

NatureScienceNEJM...

Jun 1995 Motulsky NIH report

Feb 1996 r-lentiviruses

Oct 1998 VEGF ischemia

Jess

e Gelsi

nger Oct

1999

A Fischer, E Thrasher Paris & UK Dec 2000

AAV germline Sept 2000

C Bordignon, Milano trial May 2002

First SAE Paris Sep 2002 second SAE Paris Feb 2003

Internet

Autoimmunity monkeys May 2004

SiRNA preclinical 2004

third SAE Paris Jan 2005No previous medical procedure

generated that many discussions so long before

being ever clinically applicable

How many of you have heard mostly bad news... ?mostly good news...?

1 Gene -> 1 or more functions1 Gene -> 1 or more functions

RNA(s)DNA

GENE

Protein(s)

2-5 FUNCTIONS

Gene expression

Transcription / translation

>300 ’000 functions(>150 ’000 functions)

100 ’000 genes(50 ’000 genes?)

UNIFRRusconi

2005

UNIFRRusconi

2005

Multifunctional character of genes implies: cross talk with different pathways unclarified hyerarchical position unclarified side-effects potential

Ergo to say

'one gene -> one function' is like pretending'one disease -> one drug'

Recap: what is a gene?:a regulated nanodevice for RNA production

Recap: what is a gene?:a regulated nanodevice for RNA production

RNA(s)DNA Protein(s)

GENE FUNCTIONTranscription / translation

codingspacer spacerregulatoryDNA

RNA

Therefore, to fullfil its role, a transferred gene segment must include:

regulatory sequences for Transcription proper signals for RNA Maturation/transport proper signals for mRNA Translation proper signals for mRNA Degradation

UNIFRRusconi

2005

UNIFRRusconi

2005

1 Organism -> more than 105 developmentally and genetically-controlled functions

1 Organism -> more than 105 developmentally and genetically-controlled functions

2m 2 mm 0.2mm

0.02mm

DNA RNA Protein

0.001mm Remember1 Cm3 of tissue 1'000'000'000 cells!

UNIFRRusconi

2005

UNIFRRusconi

2005

Reductionistic molecular biology paradigm(gene defects and gene transfer)

Reductionistic molecular biology paradigm(gene defects and gene transfer)

GENE transfer FUNCTION transfer

GENE KO FUNCTION KO

GENE OK FUNCTION OK

DNA

GENE

Protein

FUNCTION(s)

Gene transfer implies either: transfer of new function, or transfer of restoring function, or transfer of interfering function

UNIFRRusconi

2005

UNIFRRusconi

2005

Gene therapy as logical consequence: 'the third era'Gene therapy as logical consequence: 'the third era'UNIFRRusconi

2003

UNIFRRusconi

2003EightiesGenes as probes

ok ** ** **ok1 2 4 53

NinetiesGenes as factories

80 85 90 95 99

10

50

Y2KGenes as drugs

80 85 90 95 00

1000

3000

Ergo gene transfer is a logical

development of molecular biology

Somatic Gene Therapy (SGT) definitionSomatic Gene Therapy (SGT) definition

Definition of SGT:'Use genes as drugs':Correcting disorders by somatic gene transfer

Chronic treatment

Acute treatment

Preventive treatment

Hereditary disorders

Acquired disorders

Loss-of-function

Gain-of-function

NFP37 somatic gene therapywww.unifr.ch/nfp37

UNIFRRusconi

2005

UNIFRRusconi

2005

Why 'somatic'?Why 'somatic'?

Germ Line Cells: the cells (spermatocytes and oocytes and their precursors) that upon fertilisation can give rise to a descendant organism

Somatic Cells: all the other cells of the body

i.e. somatic gene therapyis a treatment aiming atsomatic cells and conse-quently does not lead to a hereditary transmission of the genetic alteration

Ergo transformation of germ line

cells is avoided, to exclude risk of erratic mutations due to insertional mutagenesis

germline changes are avoided also because of ethical problems

Requestioned? whenever genomic repair

systems will be perfectioned the issue of germ line therapy will probably be readdressed.

UNIFRRusconi

2005

UNIFRRusconi

2005

When/where/ may be SGT (currently) indicated?When/where/ may be SGT (currently) indicated?

No existing cure or treatment most monogenic diseases

Side effects and limitations of protein injection interleukin 12 (cancer)

-> toxic effects and rapid degradation VEGF (ischemias)

-> angiomas Factor VIII or IV (hemophilia)

-> insufficient basal level

Complement to conventional increases specificity of conventional therapy (cancer) increases efficacy of conventional therapy (hemophilia)

Life quality burden of patient costs of enzyme therapy (ex. ADA) burden of daily injections (ex. Insulin)

Ergo: there are many indications

for SGT as stand-alone or as complementary therapy

Perverse deviation dreams (with current technologyI:

gene-based sports doping performance amelioration cosmetics

UNIFRRusconi

2005

UNIFRRusconi

2005

UNIFRRusconi

2005

UNIFRRusconi

2005Pharmacological considerations for DNA transferPharmacological considerations for DNA transfer

OHOH

O

OHOH

O

O

OHOH

O

O

Mw 50- 500 Daltons Synthetically prepared Rapid diffusion/action Oral delivery possible Cellular delivery:

- act at cell surface- permeate cell membrane- imported through channels

Can be delivered as soluble moleculesÅngstrom/nm size

rapidly reversible treatment

Classical Drugs

Mw 20 ’000- 100 ’000 Da Biologically prepared Slower diffusion/action Oral delivery not possible Cellular delivery:

- act extracellularly

Can be delivered as soluble moleculesnm size

rapidly reversible treatment

Protein Drugs

Mw N x 1’000’000 Da Biologically prepared Slow diffusion Oral delivery inconceivable Cellular delivery:

- no membrane translocation - no nuclear translocation- no biological import

Must be delivered as complex carrier particles50-200 nm size

slowly or not reversible

Nucleic Acids

Ergo: Therapy with nucleic acids requires particulated formulation is much more complex than previous drug deliveries has a different degree of reversibility (intrinsic dosage / titration problem)

SGT's FOUR fundamental questions & playersSGT's FOUR fundamental questions & players

Efficiency of gene transfer

Specificity of gene transfer

Persistence of gene transfer

Toxicity of gene transfer

The variables which disease? which gene? which vector? which target organ? which type of delivery?

UNIFRRusconi

2005

UNIFRRusconi

2005

THREE classes of anatomical gene deliveryTHREE classes of anatomical gene delivery

Ex-vivo In-vivotopical delivery

In-vivosystemic delivery

V

Examples:- bone marrow- liver cells- skin cells

Examples:- brain- muscle- eye- joints- tumors

Examples:- intravenous- intra-arterial- intra-peritoneal

UNIFRRusconi

2005

UNIFRRusconi

2005

Ergo ex vivo or local delivery are

currently preferred over systemic delivery

TWO classes of gene transfer vectors: non-viral & viral delivery

TWO classes of gene transfer vectors: non-viral & viral delivery

a

b

Non-viral transfer(transfection of plasmids)

Viral gene transfer(Infection by r-vectors)

Nuclear envelope barrier! see, Nature BiotechDecember 2001

UNIFRRusconi

2005

UNIFRRusconi

2005

Ergo viral transfer is much more efficient nonviral transfer must solve a

number of hurdles

Transfection versus InfectionTransfection versus Infection

Transfection

Infection

exposed to106 particles/cell12 hours

exposed to 1 particle/cell30 min

Ergo virally mediated gene transfer is millions of times more efficent than nonviral

transfer (when calculated in terms of transfer/particle)

UNIFRRusconi

2005

UNIFRRusconi

2005

Comparing relevant issues in the two main 'vectorology' sectors (viral versus nonviral)

Comparing relevant issues in the two main 'vectorology' sectors (viral versus nonviral)

Viral vectors Packaging capacity from 4 to 30 kb problem for

some large genes (ex. dystrophin gene or CFTR gene)

important toxic load: ratio infectious/non-infectious particles from 1/10 to 1/100

strong immunogenicity: capsid and envelope proteins, residual viral genes

contaminants: replication-competent viruses (ex. wild type revertant viruses)

Viral amount (titre) obtainable with recombinants (ex. 10exp5 = poor, 10exp10=excellent)

Complexity of manufacturing (existence or not of packaging cell systems)

Emotional problems linked to pathogenicity of donor vectors (ex. lentiviruses)

Nonviral vectors Packaging capacity not an issue, even very large

constructs can be used (example entire loci up to 150 kb) minor toxic load: small percentage of non relevant

adventitious materials moderate immunogenicity: methylation status of DNA

(example CpG motifs) contaminants: adventitious pathogens from poor DNA

purification (ex endotoxins) Amount of DNA molecules is usually not a problem, the

other components depends on chemical synthesis No particular complexity, except for specially formulated

liposomes no particular emotional problems linked to the nature of

the reagents

Ergo problems that must be solved to be suitable for clinical treatment and for

manufacturing are different between viral and non-viral vectors when ignoring thir low efficiency, nonviral vectors appears largely superior

UNIFRRusconi

2005

UNIFRRusconi

2005

Short list of popular vectors/methodsShort list of popular vectors/methods

r-Adenovirus

r-Adeno-associated V.

r-Retrovirus (incl. HIV)

Naked DNA

Liposomes & Co.

Oligonucleotides

UNIFRRusconi

2005

UNIFRRusconi

2005

Recombinant AdenovirusesRecombinant AdenovirusesUNIFRRusconi2005

UNIFRRusconi2005

Manufacturing

Generation I/ II

Generation III

Hybrid adenos: Adeno-RV Adeno-AAV Adeno-Transposase

Examples OTC deficiency (clin, ---) Cystic Fibrosis (clin, --- ) Oncolytic viruses (clin, +++)

Advantages / Limitations

8 Kb capacity Generation I / II>30 Kb capacity Generation IIIAdeno can be grown at very high titers,However Do not integrate in host genome

Can contain RCAs

Are toxic /immunogenic

Recombinant Adeno-associated-virus (AAV)Recombinant Adeno-associated-virus (AAV)

Examples Hemophilia A (clin, animal, +++(autoimm?) Gaucher (clin, animal, +++) Brain Ischemia (animal, +++) Cystic fibrosis (animal, +/-) retinopathy (animal (+/-)

Advantages / Limitations

Persistence in the genome permits long-term expression, high titers are easilyobtained, immunogenicity is very low,However the major problems are: insertional mutagenesis Promotes autoimmunity? Small capacity (<4.5 kb) which does

not allow to accommodate large genes or gene clusters.

Manufacturing

Helper-dependent production

Helper independent production

Cis-complementing vectors

Co-infection

UNIFRRusconi2005

UNIFRRusconi2005

Recombinant retroviruses (incl. HIV)Recombinant retroviruses (incl. HIV)

Manufacturing

Murine Retroviruses

VSV-pseudotyped RV

Lentiviruses !

Self-inactivating RV

Combination viruses

Examples SCID (IL2R defect, Paris) (clin, +++) Adenosine Deaminase deficiency (clin, +++!!!) Parkinson (preclin, +++) Anti cancer (clin +/-)

Advantages / Limitations

9 Kb capacity + integration throughtransposition also in quiescent cells(HIV), permit in principle long-termtreatments, however disturbed by: Insertional mutagenesis

Gene silencing

High mutation rate

Low titer in manufacturing

UNIFRRusconi2005

UNIFRRusconi2005

Naked or complexed DNANaked or complexed DNA

Approaches

Naked DNA injection /biolistic

Naked DNA + pressure

Naked DNA + electroporation

Liposomal formulations

Combinations

Advantages / Limitations

Unlimited size capacity + lowerimmunogenicity and lower bio-riskof non viral formulations isdisturbed by

Low efficiency of gene transfer

Even lower stable integration

Examples Critical limb Ischemia (clin, +++) Cardiac Ischemia (clin, +/-) Vaccination (clin, +/-) Anti restenosis (preclin. +/-)

UNIFRRusconi2005

UNIFRRusconi2005

OligonucleotidesOligonucleotides

Approaches

Antisense

Ribozymes

DNAzymes

SiRNA

Triple helix

Aptamers

Decoy / competitors

Gene-correcting oligos √ !

Advantages / Limitations

reversible (except gene correcting oligos),easy manufacturing, easy deliverythese procedures may be suitable for :

handling dominant defects

transient treatments (gene modulation)

permanent treatments (gene correction)

efficacy still questionable in most cases

Examples Anti cancer (clin,preclin., +/-) Restenosis (clin, +++) Muscular Distrophy (animal, +++)

UNIFRRusconi2005

UNIFRRusconi2005

Recap: current limitations of popular vectorsRecap: current limitations of popular vectors

r-Adenovirus- no persistence- limited packaging- toxicity, immunogenicity

Biolistic bombardmentor local direct injection- limited area

Electroporation- limited organ access

Liposomes, gene correction & Co.- rather inefficient transfer

General- low transfer efficiency- no or little genomic integration

Solutions:- improved liposomes with viral properties (“Virosomes”)

UNIFRRusconi

2004

UNIFRRusconi

2004

r-AAV- no integration in host g.- very limited packaging- autoimmunity?

r-Retrovirus (incl. HIV) - limited packaging- random insertion- unstable genome

General- antibody response- limited packaging- gene silencing- Manufacturing limitations

Solutions:- synthetic viruses (“Virosomes”)

Ergo the future will probably see an increasing

interest in viral-like, but artificial particles

Technologies related to-, but not all genuinely definable as 'gene therapy'

Technologies related to-, but not all genuinely definable as 'gene therapy'

Transiently bioactive oligonucleotides antisense decoy dsDNA, decoy RNA ribozymes DNAzymes Si RNA oligonucleotides

Oncolytic viruses ONYX-15, ONYX-638 (r-adeno) r-HSV r-FSV Implants of encapsulated cells

neurotrophic factor producer cell implants hormone-producing cells

UNIFRRusconi

2005

UNIFRRusconi

2005

from www.nature.com

Genuine gene therapy oligos chimeroplasts (*gene correction induction)

Ergoamong all the above, SiRNA is among

the most promising inhibitor factors, and can conceived as transienttly acting oligo (improper gene therapy) or as permanently expressed from DNA vectors

Gene Therapy in the clinics: Trials Worldwide (cumulative)

Gene Therapy in the clinics: Trials Worldwide (cumulative)

cancer

hered.

Infect.vasc.

40

60

100

20

80

trials

500

1500

1000

patients

1992 1994 1996 19981990 2000

20% overall still pending or not yet Initiated !www.wiley.com/genetherapy

66% phase I19% phase I-II13% phase II0.8% phase II-III1.7% phase III

As of January 2005:938 cumulative protocols (90-2005)4700 treated /enrolled patients

Ergo in spite of 13 year- research only

less than 2% of the trials has reached phase III

not necessarily due to the «novel»'fail early, fail fast' paradigm

II-II

II

UNIFRRusconi

2005

UNIFRRusconi

2005

! As of Jan 1, 2004:1 approved product in China (Gendicine, by Sibiono Inc. 2004

Gene Therapy Clinical and Preclinical MilestonesGene Therapy Clinical and Preclinical Milestones

1990, 1993, 2000, 2004 // ADA deficiencyF Anderson, M Blaese // C Bordignon

Anderson, 1990

Bordignon, 2000 (ESGT, Stockholm)2002, science 296, 2410 ff)

1997, 2000, Critical limb ischemiaJ Isner († 4.11.2001), I Baumgartner, Circulation 1998

Isner, 1998

1998, RestenosisV Dzau, HGT 1998

Dzau, 1999

2000, HemophiliaM Kay, K High

2000, 2002, X-SCIDA Fischer, Science April 2000, UK trials 2003

Fischer, 20002002

2001, 2003 ONYX oncolytic VirusesD Kirn (Cancer Gene Ther 9, p 979-86)

Kirn, 2000,200120022003

Intravascular adenoviral agents in cancer patients:

Lessons from clinical trials(review)

2004, Chronic Granulomatous DiseaseM Grez Frankfurt; R Seger Zürich

Manuel GrezHans Peter HossleReinhard Seger2004

very encouraging data from just initiated clinical trial,prospected >10 patients

UNIFRRusconi

2005

UNIFRRusconi

2005

Approved commercialisation of Gendicine (Jan 2004) for cancer treatment in China

SibionoShenzen

2004, Gendicine (adeno-p53 vector)L Peng, Sibiono Inc, Shenzen, China

21 lives were so far documentedly saved by GT in european trials (x-SCID, ADA, CGD) (France, UK, Italy) (all in phase I)~200 lives quality-improved in several other phase I and II trial~nnn lives saved or quality-improved ?by Gendicine (still undocumented)

Two persisting major SGT frustration casesTwo persisting major SGT frustration cases

Muscular dystrophy (incidence 1: 3000 newborn males)

requires persistence of expression extremely large gene (14 kb transcript, 2 megaBP gene unclear whether regulation necessary unclear at which point disease is irreversible

Cystic fibrosis (incidence 1: 2500 newborns)

most luminal attempts failed because of anatomical / biochemical barrier: no receptors, mucus layer

large gene that requires probably regulation requires long term regulation unclear at which point disease becomes irreversible

In spite of genes discovered in the 90ties:

lacking suitable vector no satisfactory delivery

method no persistence treatment 'too late'

UNIFRRusconi

2005

UNIFRRusconi

2005

The most feared potential side-effects of gene transferThe most feared potential side-effects of gene transfer

Immune response to vector

immune response or long term side effects from

new or foreign gene product

General toxicity of viral vectors

Adventitious contaminants in recombinant viruses

Random integration in genome

-> insertional mutagenesis (-> cancer risk)

Contamination of germ line cells

Random integration in genome

-> insertional mutagenesis (-> cancer risk)

Ergo«The more effective is a drug, the more side effects

it will generate». SGT enjoyed a side-effect-free illusion during its

first 10-year of non-working early period Many side effects are still related to the rather

primitive state of the vectorology/delivery

UNIFRRusconi

2004

UNIFRRusconi

2004

immune response or long term side effects from

new or foreign gene product -> autoimmunity

Paris, Jan 14, 2003, A Fischer: retrovirus X-SCID (bone marrow) same cohorta second patient developed a similar leukemia 30 trials in USA were temporarily suspended

Paris, Oct 2, 2002, A Fischer: retrovirus , x-SCID (bone marrow) one patient developed a leukemia-like condition.Trial suspended and some trials in US and Germany on hold until 2003.

UPenn, Sept. 19, 1999, J. Wilson: adenovirus , OTC deficiency (liver) one patient (Jesse Gelsinger) died of a severe septic shock. Many trials were put on hold for several months (years).

SAEs1: established cases: acute and long term SAEs: from Gelsingers' death to Paris' Leukaemias

SAEs1: established cases: acute and long term SAEs: from Gelsingers' death to Paris' Leukaemias

NY May 5, 1995, R. Crystal: adenovirus, cystic fibrosis (lung) one patient mild pneumonia-like conditionTrial interrupted and many others on hold.

UNIFRRusconi

2005

UNIFRRusconi

2005

Most Recent Paris' Trial Newsdiscussed at:

www.unifr.ch/nfp37/adverse03.html

it is now rather established (2004) that the Paris' leukaemia events were caused by

treatment-specific circumstances (type of transferred gene, dosing, type of vector,

predisposition)The third SAE might delay the nextly

planned restart of patients recruitment

Paris, Jan 24, 2005, A Fischer:

retrovirus X-SCID (bone marrow) same cohort

a third patient developed a similar leukemia

what will happen?

Ergogene therapy can produce both short-term and long-term severe side effects through acute immunogenicity or insertional mutagenesis (cancer risk)

Parenthesis: future solutions to insertional mutagenesis: targeted gene transfer approaches

Parenthesis: future solutions to insertional mutagenesis: targeted gene transfer approaches

Random integrating vectors r-retroviruses r-lentiviruses r-AAV plasmids (low frequency) plasmids + transposase (eg 'sleeping beauty')

Transient, non integrating vectors adenovirus plasmid RNA virus based oligonucleotides (SiRNA, antisense, ribozymes) artificial chromosomes

Gene correction vectors chimeroplasts (RNA-DNA chimeric oligos) single stranded DNA (homologous recom)

Ergo genotoxic non-genotoxic

Specifically integrating vectors hybrid vectors (HSV-AAV) Phage 31 integrase-based designer integrases (ZnFinger proteins)

UNIFRRusconi

2005

UNIFRRusconi

2005

Ergovector systems that allow specific or at least better location-controlled gene delivery are experimentally well advanced (see accompanying text)

SAEs2: emerging cases mid-term effects documented by recent Autoimmunity Reports

SAEs2: emerging cases mid-term effects documented by recent Autoimmunity Reports

Blood, 1 May 2004, Vol. 103, No. 9, comment: pp. 3248-3249Autoimmunity in EPO gene transfer (macaques)Els Verhoeyen and François-Loïc Cosset

Papers:- Chenuaud and colleagues (page 3303)- Gao and colleagues (page 3300)

inadvertent autoimmune response in nonhuman primates resulting from transfer of a gene encoding a self-antigen.- delivered the homologous EPO cDNA driven by ubiquitous and/or regulatable promoters via AAV vectors injected in muscle or aerosolized in lung, resulting in supra-physiologic serum levels of EPO, from 10- to 100 000- fold over the baseline

UNIFRRusconi

2005

UNIFRRusconi

2005

K High, ASGT June meeting 2004[Abstract1002] Immune Responses to AAV and to Factor IX in a Phase I Study of AAV-Mediated, Liver-DirectedGene Transfer for Hemophilia B

Ergosomatic gene transfer can generate mid-term auto- immunity under certain circumstances

SAEs3: Non-science factors that have disturbed progress and image of gene therapy

SAEs3: Non-science factors that have disturbed progress and image of gene therapy

'Naive' statements in the early 90ties

Excess of speculative financing in mid-late 90ties.

Concomitance with stock-market euphoria

Reckless statements/promises or misreporting in late 90ties

Tendency by the media to spectacularise good and/or bad news

Ergo too much money, too much time pressure, too much media

exposure among the image killer factors. The fundamental error: we pretended making a business issue

out of a scientific issue

UNIFRRusconi

2005

UNIFRRusconi

2005

1625

Ups and Downs of Gene Therapy: a true roller-coaster ride!

Ups and Downs of Gene Therapy: a true roller-coaster ride!

>90

high

Low

moo

d

NIHMotulskireport

Lentivectors

Adeno III

J. Isner

F Anderson

R. Crystal

Adeno I

A. FischerM. Kay

AAV germline in mice?

Ergo whenever a reasonable cruise

speed was achieved, a major adverse event has brought us back «square one» or even below

V.Dzau

Paris I and IILeukaemias

J. Gelsinger

90 91 92 93 94 95 96 97 98 99 00 01 02 03 04

UNIFRRusconi

2005

UNIFRRusconi

2005

05

C Bordignon

5

lentivectorshopes

Auto-immunity

gendicine

Paris III

?

?

?

4 companies

Conclusions: GT has proven several concepts, has several tools, but is still in the pioneering phase

Conclusions: GT has proven several concepts, has several tools, but is still in the pioneering phase

Fundamentally many new potentially therapeutic genes identified All types of diseases can be virtually treated by gene

transfer we start to manage efficiency, specificity, persistence and

toxicity

Vectors and models Choice of among a number of viral and non viral vectors Viral vectors have the advantage of efficiency nonviral vector the advantage of lower toxicity/danger. Viral vectors have the disadvantage of limited packaging

and some toxicity nonviral vectors have the major disadvantage of low

efficiency of transfer

Clinically over 600 trials and >4000 patients in 15 years only a handful of trials is now reaching phase III Progress further slowed down by periodical pitfalls 1 product/treatment approved in China 2004 (gendicine)

Ergo we are somewhat ahead but still

in the pioneering phase !

«failure of evidence» does not mean «evidence of failure» !

UNIFRRusconi

2005

UNIFRRusconi

2005

Perspectives: somatic gene therapy will progress in spite of all past, present and future incidents/accidents

Perspectives: somatic gene therapy will progress in spite of all past, present and future incidents/accidents

Fundamental level & vectorology

Better understanding of gene interactions and networking Gene inhibition through Si RNA, Zn finger specifically integrating gene constructs artificial chromosomes become more realistic novel, semi-artificial particles

Preclinically scaling up to larger animal models (dog and monkey) new transgenic models may give improved similarities to

human diseases

Clinically Use of recombinant lentiviruses Increase of Phase III procedures over the next 5 years therapeutical applications may be registered within 3-5

years challenge by other emerging therapies

Ergo many adverse events were due rather

to human errors than to intrinsic dangers

other undesired effects are due to prototypic state of tools

hurdles can be overcome the genuine potential of SGT is

intact

UNIFRRusconi

2005

UNIFRRusconi

2005

Proust's questionnaire to myself and to you, concerning gene therapy

Proust's questionnaire to myself and to you, concerning gene therapy

UNIFRRusconi

2005

UNIFRRusconi

2005

will GT ever make it into routine clinical practice ? yes

The most worrying side-effect? immunity

Which will bloom: viral or non viral transfer? combination thereof

Is insertional mutagenesis an important hurdle? No

Who will 'win' the race: gene transfer or cell therapy? both or neither

Will GT be applicable also for non-severe conditions? yes

Which will be the best inhibitor function: antisense, intrabodies, aptamers, ribozymes, SiRNA, designer Zn Fingers, triple helix, small drugs, ...whatever ?

...whatever

Thank you all for the patience and attention,

sandro.rusconi@unifr.chor visit:

www.unifr.ch/nfp37/

...Thanks, and let's remain optimistic...Thanks, and let's remain optimistic

The other organisers

Sergio Capancioni, Christiane Damgé

GTRV Debio summer school

UNIFRRusconi

2005

UNIFRRusconi

2005

Ergo let's look forward

to a safe landing

That's all, folks!That's all, folks!UNIFRRusconi

2005

UNIFRRusconi

2005

www.unifr.ch/nfp37

UNIFRRusconi

2004

UNIFRRusconi

2004