safety and immunogenicity for gene therapy medicinal products and therapeutic vaccines ·...

Dr. Nadine Kirsch-StefanDr. Mark Goldammer

Paul-Ehrlich-Institut

Safety and Immunogenicity for Gene Therapy Medicinal Products and Therapeutic Vaccines

Dr. Nadine Kirsch-Stefan and Dr. Mark Goldammer

27th AGAH Annual Meeting26.-27.04.2018, Munich

Nadine Kirsch-Stefan, Mark Goldammer

Gene Therapy Medicinal Products (GTMP)

Source: EMA and NIH https://stemcells.nih.gov/info/Regenerative_Medicine/2006Chapter4.

“…contain genes that lead to a therapeutic, prophylactic or diagnostic effect. Theywork by inserting 'recombinant' genes into the body, usually to treat a variety ofdiseases, including genetic disorders, cancer or chronic diseases.”


Vectors used for Gene Therapy

Vectors

Non-viral Viral

integrating non-integrating

Key requirements for a viral vector:

• Safety• Low toxicity• Stability• Cell type specificity


Vectors used for Gene Therapy based on Scientific Advice (PEI)

Retrovirus (30,2%)

Adeno-associated virus (24%)

Lentivirus (21,9%)

recombinant bacterium (10,4%)

RNA (9,4%)

Adenovirus (8,3%)

Source: PEI, only data > 8%

Cumulative data 2012 – 11/2017


Retroviral and lentiviral vectors

Safety and immunogenicity:

• Humoral immune response rather low• Integration into host cell genome raises the possibility of

insertional mutagenesis and oncogene activation• Generation of a replication competent virus

Technological approaches:

• Development of self-inactivating (SIN) vectors • Use of tissue specific promoters• Clonal analysis

Vector Transduction Genome Advantage

Retroviral Only dividing cells Integrated • Persistent gene transfer (stem cells)• High transduction efficiency

Lentiviral Dividing andnon-dividing cells

Integrated • Transduction of non-diving cells• Receptive to pseudotyping

Retrovirus7-10 kb genome

Source: Kaufmann JK & Nettelbeck DM (2012) Trends Mol Med


Adenoviral vectors


• Strongly immunogenic

• Vector can trigger an inflammatory response leading to

multiorgan failure (OTC clinical trial, 1999)

Advantage:

• Extremely efficient transduction of most tissues

Technological approaches:

• Extensive engineering to reduce immunogenicity

Today mainly used as vaccine and oncolytic virus Adenovirus~36 kb genome



Adeno-associated viral (AAV) vectors


• Reduced transduction efficiency due to pre-existing humoral immunity• Loss of transgene expression due to induction of cellular immune

response against the viral capsid• Repeated dosing not possible due to neutralizing antibodies

Advantage:• Non-pathogenic• Excellent safety profile • Wide tissue tropism

Countermeasures:• Use of serotypes with low pre-existing immunity• Immunosuppression • Optimization of transduction efficiency and transgene expression• Monitoring of immune responses


Adeno-associated virus4,7 kb genome


Chimeric Antigen Receptor (CAR) T cells


• Neurotoxicity• Cytokine release syndrome (CRS)• Tumor-lysis syndrome (TLS)• Immune reactions against mouse scFv• Off-target toxicities (i.e. B-cell aplasia and tissue damage)

Advantage:• Specific targeting of T cells via CAR• Clinical benefit in B cell malignancies (CD19-CAR T cells)

Countermeasures:• Use of humanized scFv• Identify biomarkers to predict common toxicities• 4th generation CARs and smart CARs

Source: Lawrence J (2016) The Pharmaceutical Journal


Addressing safety of GTMPs in NC studies

• Human specificity of the GTMP• Selection of a relevant animal model • Often single administration to induce long lasting effect• Translation of dose-response from animal models to humans

Challenges:

• Biodistribution is fundamental to identify target organs• Correlation of dose and expression of transgene (systemic and local)• Pharmacokinetics should be known before planning relevant studies• Specific aspects related to nature of GTMP should be considered

Addressing safety in non-clinical studies:


Scientific Advice in preparation for a Clinical Trial

• Receive procedural and regulatory advice• Discuss specific project and product related aspects• Get answers on quality, non-clinical and/or clinical issues

National Scientific Advice


Safety and Immunogenicity for Gene Therapy Medicinal Products and Therapeutic Vaccines

Therapeutic Vaccines


Therapeutic Vaccines

Other antigen delivering principles:

• RNAs• Virus like particles

Peptides [non biotechnology-derived] - examples:

• Cancer Preferentially expressed in tumour cells, such as Tyrosinase, MAGE or PRAME Neo-antigens

• Neurodegenerative diseases

α-synuclein, tau and amyloid-β

Cell therapies:

• Antigen dendritic cells (DCs)• Natural killer cells (NKs)• CMV or EBV specific T-cells

…etc


Development of Therapeutic Vaccines in Germany (PEI)

6 6

89 9

5

109

1112 12

16

10

7

10

7

0

2

4

6

8

10

12

14

16

18

2010 2011 2012 2013 2014 2015 2016 2017

Num

ber


Clinical Trial Applications

Source: PEI


Safety & Immunogenicity – Therapeutic Vaccines

Immunotoxicity is defined as unintended immunosuppression or enhancement:

1) Drugs intended to modulate immune function for therapeutic purposes (e.g. to prevent organ transplant rejection) where adverse immunosuppression can be considered as exaggerated pharmacodynamics[also → Cytokine release syndrome]

2) Drugs not intended to affect immune function… → does not apply for therapeutic vaccines

ICH S8… does not apply to biotechnology-derived pharmaceutical products covered by ICH S6



4.5. Immunotoxicity studies

…standard testing batteries, however, are not recommended ...

3.6. Immunogenicity [Foreign Antigens]

…Many biotechnology-derived pharmaceuticals intended for human are immunogenic in animals. Therefore, measurement of antibodies associated with administration of these types of products should be performed when conducting repeated dose toxicity studies in order to aid in the interpretation of these studies…

… The induction of antibody formation in animals is not predictive of a potential for antibody formation in humans …



2. Species selection2.1. General principles…Comparisons of target sequence homology between species can be an appropriate starting point…

…when no relevant species can be identified because the biopharmaceutical does not interact with the orthologous target in any species, use of homologous molecules or transgenic models can be considered...



→ refers directly to tumour vaccines:

6.3.2. Immune-modulating compounds including tumour vaccines…Monitoring the immune response… to determine appropriate dose and schedule…

6.4.2. Combinations involving a non-cytotoxic drug…Co-enhancement is considered when both combination partners demonstrate (modest) anti-tumour activity per se and the anti-tumour activity of the combination is considerably increased. In phase II, the new combination should …

Applicants should also refer to:



In general:

• The pre-clinical programme should address the product-specific& all relevant safety concerns to the best extent

• A robust rational justifying the selected starting dose for a FIH must be provided → based on pre-clinical data

• Limitations of the available pre-clinical data have to be addressed appropriately for the planning, design and conduct of a FIH study

You may consider:

• Testing cytokine induction/inhibition → multiplex assays available• In relevant animal models – e.g. using homologous molecules

Haematology Organ toxicity – histology …


Safety & Immunogenicity – Experiences(neither comprehensive nor complete analysis - indications)

• Provenge®: Antigen-presenting cells loaded with recombinant fusion protein antigen, which contains both PAP (prostatic acid phosphatase) and GM–CSF (granulocyte-macrophage colony-stimulating factor) demonstrated improve overall survival in patients with androgen-dependent prostate cancer (ADPC) -achieved marketing authorisation in the EU and USA

Successful:

• Cancer: A trend towards using Neo-epitopes → specificity ↑• Combining therapeutic vaccine approaches + e.g. innovative adjuvants such as

cytokines or toll-like receptor agonists, check-point inhibition, etc.

Due to current experience, clearly related, severe adverse effects (other than injection side reactions) are relatively uncommon

Clinical studies demonstrate more and more targeted immunogenicity in humans

However - do not necessarily translate into clinical effects

Trends:

In general:


Safety & Immunogenicity – Immune Response & Clinical Effects

Tox/Safety Pharmacology

Immunogenicity

Pharmacology

Translation

inHumansinHumans

Pre-ClinicalProgrammePre-ClinicalProgramme



Immunogenicity

Pharmacology

Translation

inHumansinHumans


?

???




Immunogenicity

Pharmacology


inHumansinHumans

Translation




• Establishing product specific → predictive (animal) models No standard testing batteries recommended – however, guidelines give indications which relevant / critical safety aspects have to be addressed

Understanding of immunogenicity and prediction of immune answer and (extent) of clinical effects in humans[Tumour environment? Tumour escape? …]

Challenges:

• Early initiation of comprehensive product specific development plans

• Establishing a good understanding of mode of action → Prediction of (extent) of clinical effects (Safety & Efficacy)

• Early communication with regulatory agencies

Recommendation:


Thank you for your attention.

Further information on national Scientific Advice is available on the website of the Paul-Ehrlich-Institut: www.pei.de/innovation-office


Development of Gene Therapies in Germany (PEI)

10

4

21

9

14

22

34

27

4

9

6

3

8

18 18

30

0

5

10

15

20

25

30

35

40

2010 2011 2012 2013 2014 2015 2016 2017

Num

ber


Clinical Trial Applications

Source: PEI


Vectors used for Gene Therapy worldwide

Retrovirus (14,5%)

Lentivirus (18,5%)

Adenovirus (16%)

Adeno-associated virus (14,4%)

Naked/Plasmid DNA (14,4%)

Source: Adapted from Wiley, The Journal of Gene Medicine, only data > 8%



Gene Therapy Clinical Trials in Europe

UK (n=221)

Germany (n=92)

France (n=59)

Netherlands (n=37)

Spain (n=37)

Italy (n=28)

Belgium (n=22)

Sweden (n=13)

Source: Adapted from Wiley, The Journal of Gene Medicine, only European countries with n>10



Gene Therapy Clinical Trials in Europe vs. US

US (n=1643)

Europe (n=527)

Source: Adapted from Wiley, The Journal of Gene Medicine


safety and immunogenicity for gene therapy medicinal products and therapeutic vaccines ·...

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