Download Nonclinical, Cell-Based Therapy Testing

Issue 200 | April 2012
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NONCLINICAL, CELL-BASED THERAPY TESTING –
A COMPREHENSIVE SERVICE
With the advancement of cellular therapeutics in clinical use following Investigational New Drug submissions and marketing
approvals in the United States, Europe and the rest of the world, there is a heightened concern for the safety of these promising
therapies due to the potential of adverse effects in the patient. Cell-based therapies present unique challenges, including
the selection of the relevant animal model(s) as well as the design of comprehensive studies for the cell-based product.
Considerations include: cell survival and differentiation, cell distribution and the potential for tumor formation. Additionally, cells
must be well-characterized, as the extent of the preclinical program is contingent upon genetic manipulations and modifications
of the cell line.
At Charles River Preclinical Services (PCS), highly experienced groups of scientists provide scientifically sound and effective
strategies and customized protocols, as well as offer a complete range of services to execute a program for the preclinical testing
of cell-based therapeutic products.
Preclinical Program Design
Many approaches can be used to determine the safety of a cell-based
therapy. The types of programs that can satisfy regulatory expectations
are broadly addressed in various guidance documents.
So that critical issues can be identified and addressed as soon as
possible, developers of cellular therapy products are encouraged to
have an early discussion with regulatory agencies in order to review
study designs before their conduct.
When developing a cell therapy program, it is important to incorporate
design aspects which address potential concerns within regulatory
guidelines. Our scientific staff customizes programs around the novel
properties of each cellular product.
Preclinical Questions Similar to Drugs/Biologics
• What are they?
• What do they do?
• Best way to test?
• Where do they go?
• How long do they stay?
• Are they safe?
• What can they turn into?
Cell Characterization
Activity
Animal Model
Biodistribution
Biodistribution
Toxicity
Tumorigenicity
Figure 1.
A well-positioned cell therapy program addresses the questions shown in Figure 1 and outlined in Figure 2.
Cell therapy preclinical programs and biologic or drug toxicology programs have similar challenges. Both must support clinical
trials as well as demonstrate product safety. A consistent, well-characterized, biocompatible product with biomarkers related to
pharmacology is required. Route of administration and regimen should mimic the proposed clinical program to evaluate local and
chronic toxicity, including off-target effects. In addition, dose-response, biodistribution and the fate of the cells in the test system
need to be demonstrated. The cellular therapeutic product must be thoroughly evaluated for tumor formation potential as well.
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Cell Manufacturing,
Characterization and Detection
Cell Characterization and Handling
In order to successfully develop a program that meets
regulatory expectations, the cell source, type and degree of
manipulation must be considered.
Before initiating preclinical studies, the cell line must be wellcharacterized. Characterization of cells should include, but
not be limited to, 1) identity and composition; 2) viability and
stability; and 3) purity and sterility.
Surgical Capabilities
We are the premier provider of surgically altered research
models (e.g. the middle cerebral artery occlusion (MCAO)
stroke model and bone healing models). Our highly
skilled surgeons have experience with various surgical
cell implantation methods which mimic clinical routes of
administration (e.g., injection into the brain or spinal cord using
stereotaxic devices or intraocular instillations).
Both Charles River Preclinical Services and Biopharmaceutical
Services (BPS) utilize dedicated, state-of-the-art cell culture
facilities and employ expert scientific staff to offer services
such as cell characterization, cell banking, long-term
cryopreservation, as well as preparation and analysis of cells
for administration.
Cell Detection (Identity and Composition)
Cell-based therapeutics present Chemistry, Manufacturing
and Control (CMC) issues and must be recognized as a
heterogeneous mixture of cells. To properly identify the cells,
a series of translation biomarkers must be developed. These
include morphology, surface, and genetic markers–qualified
and optimized for the cell target.
GLP-compliant molecular pathology services at
Charles River (in situ hybridization and PCR-based evaluations)
allow exact identification of cells in tissues. The integration
of molecular biology and histopathology capabilities (as
described below) allows for the correlation of gene expression
to tissue histomorphology, which provides valuable functional
genomics information.
Animal Model
Charles River can assist in choosing a test system for
proof of concept studies as well as help recommend a
pharmacologically sensitive species that will serve as a
progressive host for the cellular therapeutic, with consideration
given to the intended clinical route of administration.
Charles River has experience with immunocompetent
and immunocompromised rodents (including neonates),
nonhuman primates and surgically altered animals. Animals
with competent immune systems can be treated with
immunosuppressant agents to enable cell survival after
implantation. Facilities are available to conduct studies
in immunocompromised animals that require controlled
environments (i.e. flexible film isolators, clean rooms or
microisolator cages).
Study Design Options
Charles River offers many design options for studies involving
cellular therapeutics.
Pilot Tolerability, Viability and Biodistribution Studies
• Provide preliminary data on the maximum tolerated dose,
cell survival and/or early testing of the cellular therapy
product. Pilot studies are used to provide a strong proof
of concept in the selected animal model(s), including
elucidating the route of administration and dosing regimen,
dose response and onset, as well as durability of effects.
Biodistribution Study
• Evaluate the local migration and systemic distribution of the
cellular therapeutic, ultimately determining cell fate. The cell
product is evaluated for survival, integration in non-target
tissues, as well as the ability to endure in the animal model
at the target site for durability, differentiation and migration
in vivo. Generally these studies are GLP-compliant. A
complete profile of tissues is retained for histopathology,
immunohistochemistry and/or PCR evaluation.
Toxicity Evaluation
• GLP evaluation of the product’s safety over a dose range
via the intended clinical route of administration. Standard
toxicological evaluations are performed, including
clinical observations, body weight and feed consumption
measurements, ophthalmologic and clinical pathology
evaluations, and complete necropsy, organ weight and
histopathology assessments. While systemic toxicity may
be less of a concern for cellular therapeutic products,
immunogenicity concerns and irreversibility of engraftment
must be considered.
Tumorigenicity Study
• Assess the potential for cell phenotypic stability or ectopic
tissue formation by a cellular therapy product in an
immunocompromised rodent. Single subcutaneous or
clinical route administration with at least three dose groups
(including positive control). Rodents are palpated weekly for
mass presence and tissues are retained for histopathology
and cell detection (if applicable). Study duration is typically
the lifespan of the animal.
Pathology and
Immunohistochemistry
Charles River is the largest provider of toxicologic pathology
research services in the contract research industry. We offer
a wide variety of specialty, pathology-based disciplines.
In addition to traditional toxicologic pathology studies, we
provide:
• GLP-compliant necropsy, histology and histopathology
services
• State-of-the-art, molecule-specific techniques
Immunohistochemistry techniques allow for the visualization
and morphometric analysis of implanted or transformed cells
in target tissues. Such techniques identify target antigenic cell
components to highly specific antibodies labelled with visible
markers for microscopic examination. Capabilities at Charles
River include:
• Validated, tissue-based methods
• Development of customized procedures to assess the
activity of test material
• Interpretation of specimens by pathologists
• Application of quantifiable morphometric techniques
Global Scientific, Regulatory
and Program Management
Services
Toxicology experts at Charles River can recommend strategic
study design options and offer scientific guidance for a
program. In addition, they work to develop strong partnerships
with regulatory reviewers. A dedicated program manager
oversees programs from initial contact through final reporting.
Our consultants are also available to help interpret data and
handle regulatory questions to ensure that preclinical work
supports clinical objectives.
Preclinical Cellular Therapeutic Safety Study Design Considerations
Cell Detection Methods
Cell Characterization
Identity
Purity and Sterility
Viability and Stability
Heterogeneous mixture
Descriptive (not quantitative)
Free from impurities
and contaminants
Lot release and expiration
Avoid process changes
• Develop, validate and employ
translational biomarkers
• Optimize morphology, surface and
genetic markers
Human
HumanTonsil
Tonsil(10X)
(10X)
Anti-Ki-67
Anti-Ki-67
Mouse
IgG
Mouse IgG
EE
E E
LFLF
LF
• PCR
• IHC
• In vivo imaging
Key: E = Epithelium, LF = Lymphoid follicle
Animal Model Selection
Key: E = Epithelium, LF = Lymphoid follicle
Product Activity
Influenced by engraftment of cells
and translatability to humans
• Engraftment may require a disease model
Need strong proof of concept
• Assess in vitro activity
• May be same as lot release assays
• Assess in vivo activity - Consider
• Consideration for delivery
• Model of disease
• Patient population
• Anatomic p
parity
y with human tissue
• Site impact and reactions
• May need to study the full human dose
• Develop and employ translational
study designs
• Immunosuppression may be required
• Route / regimen
• Surgery
S
emulating
l i clinical
li i l use
• Dose response / biomarkers
• Onset of effect
• Durability of effect
• Pathology
•C
Chemically
e ca y o
or ge
genetically
et ca y co
compromised
p o sed rodents
ode ts
• Must be robust enough to endure chronic toxicity
duration
• Assess transplantation risks
Failure to engraft can lead to clinical hold
(“No exposure” = no study)
Activity model may = safety model
.
Toxicity / Safety
Like Drugs…
Unlike Drugs…
• Method of delivery does not
confound toxicity
• Less concern for systemic
toxicity
• Incorporate appropriate
controls
t l
• Evaluate efficacy end points
• Evaluate several doses
• GLP-study may be in one
animal model of disease
• Standard toxicological
evaluations
• Immunogenicity concerns
• Clinical observations, body
weights and feed consumption
• Ophthalmologic and clinical
pathology
p
gy evaluations
• Necropsy; organ weights;
histopathology
• Host
H t and
d graft
ft immunoreactivity
i
ti it
• Cell migration in vivo
• Irreversibility of engraftment
or effects
Biodistribution
• Ensure cells persist in animal model
• Evaluate
E l t target
t
t site
it (durability)
(d bilit )
• Affirm migratory potential is limited
• Non-target tissues
• Define systemic distribution and cell fate
• Preliminary results justify duration of
safety studies
• Consider incorporating definitive evaluations
i t safety
into
f t studies
t di
• Sacrifice at appropriate interval(s)
based on cell longevity in the model
Tumorigenicity
Cell phenotypic stability in vivo
Ectopic tissue formation
Single subcutaneous
or clinical route of
administration
Observation over lifespan of the model (>6 months)
• Palpated weekly for mass presence
• Tissues retained for histopathology and cell detection
• Positive control required
Figure 2.
References
Guidance for Industry - CBER Characterization and Qualification of Cell Substrates and Other Biological Materials Used in the
Production of Viral Vaccines for Infectious Disease Indications. February 2010. Rockville (MD), U.S. Dept of Health and Human
Services Food and Drug Administration, (CBER).
Guidance for Industry: Source Animal, Product, Preclinical, and Clinical Issues Concerning the Use of Xenotransplantation
Products in Human. Final Guidance; April 2003. U.S. Food and Drug Administration Department of Health and Human
Services,(CBER).
EMEA Guideline on human cell-based medicinal products. EMEA/CHMP/410869/2006; Adoption 30 May 2008. EMEA – CHMP.
Guidance for Industry: guidance for human somatic cell therapy and gene therapy. March 1998. FDA,(CBER).
For additional information, please visit The SourceSM, a secure portal that provides registered users with direct access to the
technical, scientific and educational resources available from Charles River. To register, please visit www.criver.com/thesource
North America: 1.877.274.8371 • email: [email protected]
Europe: +44 (0) 1875 614545 • email: [email protected]
Asia: +81 (0) 45 474 9340 • email: [email protected]
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