Examples of Potential Preclinical Projects

1
Examples of Potential Preclinical Projects

• Mark N. Milton. Ph.DVP, Nonclinical Development
• Tempo Pharmaceuticals, Inc

2
Hypothesis

• The examples are designed to test the hypothesis
  that models can be created to describe certain in
  vivo properties of nanoparticles as a class
• The studies will either support or refute this
  hypothesis
• Could result in a standard testing paradigm or
  the need for a case-by-case testing paradigm

3
Rationale

• Testing can readily be performed in animals but
  the data will only be relevant if the findings
  can be translated to humans
• Therefore, the proposed examples will contain
  elements that fall into the clinical arena

4
Examples of potential projects

• What is the effect of particle size on the
  distribution of a non-targeted nanoparticle that
  is intended to be used as a therapeutic agent?
• Can nanoparticles be absorbed after oral
  administration?
• Can non-targeted nanoparticles cross the
  placenta?
• Which diseases may be amenable to being treated
  with non-targeted nanoparticle based drugs?

5
Example 1

• What is the effect of particle size on the
  distribution of a non-targeted nanoparticle that
  is intended to be used as a therapeutic agent?

6
Example 1Objectives

• Determine potential organs of toxicity
• Determine routes of excretion
• Determine potential diseases that can be treated
  with non-targeted nanoparticles
• Will provide information that will complement
  Example 4
• To develop a model that can predict the fate of a
  nanoparticle in vivo

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Example 1 Assumptions

• Size is the major driver of the distribution of a
  nanoparticle
• The type of nanoparticle (liposome, dendrimer
  etc) does not impact the distribution of the
  nanoparticle
• The size of the nanoparticle does not change with
  time in vivo
• The nanoparticles do not degrade (i.e. are
  stable) in vivo
• Incorporation of a drug in, or conjugation of a
  drug to, a nanoparticle does not change its
  physical properties or distribution
• Concentrations of nanoparticle can be determined
  accurately in tissue samples
• The nanoparticle will be administered
  intravenously (most common route of
  administration to date)
• Distribution after a single dose will be
  predictive of distribution of subsequent doses of
  nanoparticle

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Example 1 Step 1 Model development

• Nanoparticles of varying sizes will be used in
  this study.
• e.g. 10 nm, 30 nm, 80 nm, 150 nm, 200 nm, 400 nm
• Nanoparticle (containing radiolabel) will be
  administered to rats by bolus IV administration.
  
• Rats (N3) will be sacrificed at selected
  timepoints and analyzed by QWBA
• The exposure to the nanoparticle in particular
  organs will be determined.
• Urine and feces will be collected for
  quantitation of amount of nanoparticle excreted

9
Example 1 Step 1 Model development

• Study could also include microautoradiography
  and/or confocal microscopy in order to determine
• Distribution within a given tissue
• Uptake into cells
• Alternative study design could replace
  autoradiography with tissue excision and
  radioactivity determination (by LSC or AMS)

10
QWBA
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Example 1 Step 1 Model development

• Rationale
• Rats will be used since it is a standard rodent
  species used in the safety assessment of NCEs
• By using the rat, we will be able to generate
  data that can be relevant to the risk assessment
  of the safety of a nanoparticle that will be used
  as a therapeutic
• IV administration is the most common route of
  administration for nanoparticle based
  therapeutics

12
Example 1Step 2 Method Validation

• A nanoparticle (differing in composition to that
  used in step 1) will be produced at two different
  sizes (e.g. 80 nm and 150 nm)
• The distribution and excretion of the particle
  will be determined as described in Step 1

13
Example 1Step 3 Method Translatability

• A nanoparticle of a fixed composition and of two
  different sizes (e.g. 80 and 150 nm) will be
  administered to dogs
• The distribution and excretion of the particle
  will be determined as described in Step 1
• Tissue excision may be required since performing
  QWBA studies in dogs can be problematic
• The dog has been selected as the second test
  species based on its common use as the non-rodent
  species in the safety assessment of NCEs

14
Example 1Step 4 Applicability Of Model To Real
Life Situations

• A nanoparticle of fixed composition and of two
  different sizes (e.g. 80 and 150 nm) will be
  generated in radiolabeled and non-radiolabeled
  form
• Rats will be administered a single dose of the
  non-radiolabeled nanoparticle
• Subsequently (one week later?) the same rats will
  be administered a dose of the radiolabeled
  nanoparticle and the distribution of the
  nanoparticle will be determined as described in
  Step 1

15
Example 1Step 5 Validation Of Model In Humans

• A nanoparticle of fixed composition and of two
  different sizes (e.g. 80 and 150 nm) will be
  generated
• The nanoparticle will contain an imaging agent
• The nanoparticle will be administered (at
  microdose level) to human volunteers and the
  distribution of the nanoparticle determined using
  imaging techniques
• Since microdose levels of nanoparticles will be
  administered, the clinical trial could be
  conducted under an Exploratory IND rather than a
  traditional IND

16
Example 1Data Interpretation

• It should be noted that the observation that a
  nanoparticle distributes to a particular tissue
  does not necessarily mean that toxicity will be
  observed in that particular tissue or that the
  nanoparticle will be efficacious
• However, if the nanoparticle does not distribute
  to a given tissue, the possibility of toxicity
  and/or efficacy is low
• If the nanoparticle is not stable, the data
  generated will represent the distribution of the
  intact nanoparticle and/or its metabolites/degrada
  tion products
• Assessment of the uptake into cells will be
  required for full data interpretation

17
Example 2

• Can nanoparticles be absorbed after oral
  administration?

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Example 2Objectives

• To determine whether nanoparticles can be
  absorbed after oral administration
• To develop a model that can predict the fate of a
  nanoparticle in vivo

19
Example 2Assumptions

• Size is the major driver of the distribution of a
  nanoparticle
• The type of nanoparticle (liposome, dendrimer
  etc) does not impact the distribution of the
  nanoparticle
• The size of the nanoparticle does not change with
  time in vivo
• The nanoparticles do not degrade (i.e. are
  stable) in vivo
• Incorporation of a drug in, or conjugation of a
  drug to, a nanoparticle does not change its
  physical properties or distribution
• Concentrations of nanoparticle can be determined
  accurately in tissue samples
• Distribution after a single dose will be
  predictive of distribution of subsequent doses of
  nanoparticle

20
Example 2 Step 1 Model development

• Nanoparticles of varying sizes will be used in
  this study.
• e.g. 10 nm, 30 nm, 80 nm, 150 nm, 200 nm, 400 nm
• Nanoparticle (containing radiolabel) will be
  administered to portal-vein cannulated rats by
  oral gavage administration.
• Blood will be collected at selected timepoints
  and concentrations of radioactivity determined by
  LSC or AMS
• Rats (N3) will be sacrificed at selected
  timepoints and GI mucosa, liver and lymphatic
  fluid collected. Concentrations of radioactivity
  will be determined by LSC or AMS
• Urine and feces will be collected for
  quantitation of amount of nanoparticle excreted

21
Example 2 Step 1 Model development

• Rationale
• Rats will be used since it is a standard species
  used to assess the toxicity of NCEs
• By using the rat, we will be able to generate
  data that can be relevant to the risk assessment
  of the safety of a nanoparticle that will be used
  as a therapeutic
• Oral administration is the most common route of
  administration for therapeutics for non-life
  threatening diseases and certain anti-cancer
  drugs

22
Example 2Step 2 Method Validation

• A nanoparticle (differing in composition to that
  used in step 1) will be produced at two different
  sizes (e.g. 80 nm and 150 nm)
• The distribution and excretion of the particle
  will be determined as described in Step 1

23
Example 2Step 3 Method Translatability

• A nanoparticle of a fixed composition and of two
  different sizes (e.g. 80 and 150 nm) will be
  administered to dogs
• The distribution and excretion of the particle
  will be determined as described in Step 1
• Nanoparticle could be administered in
  solution/suspension or in a capsule
• The dose could be administered via Intestinal
  Access Ports in order to determine sites of
  absorption
• The dog has been selected as the second test
  species based on its use in toxicity assessment
  of NCEs and its use in the preclinical assessment
  of novel oral formulations

24
Example 2Step 5 Validation Of Model In Humans

• A nanoparticle of fixed composition and of two
  different sizes (e.g. 80 and 150 nm) will be
  generated
• The nanoparticle will contain an imaging agent
• The nanoparticle will be administered (at
  microdose level) to human volunteers and the
  distribution of the nanoparticle determined using
  imaging techniques
• An evaluation of the site of absorption could be
  determined by using a device such as the
  Enterion capsule
• An alternative approach could be to administer a
  microdose of nanoparticle that includes low
  levels (nCi) of radioactivity and determination
  of concentrations of radioactivity in the plasma

25
Example 2Data Interpretation

• If the nanoparticle is not stable, the data
  generated will represent the absorption of the
  intact nanoparticle and/or its metabolites/degrada
  tion products

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Example 3

• Can non-targeted nanoparticles cross the
  placenta?

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Example 3Objective

• To determine whether non-targeted nanoparticles
  can cross the placenta and hence lead to a class
  effect in terms of teratogenicity

28
Example 3Assumptions

• Size is the major driver of the distribution of a
  nanoparticle
• The type of nanoparticle (liposome, dendrimer
  etc) does not impact the distribution of the
  nanoparticle
• The size of the nanoparticle does not change with
  time in vivo
• The nanoparticles do not degrade (i.e. are
  stable) in vivo
• Incorporation of a drug in, or conjugation of a
  drug to, a nanoparticle does not change its
  physical properties or distribution
• Concentrations of nanoparticle can be determined
  accurately in tissue samples
• The nanoparticle will be administered
  intravenously (most common route of
  administration to date)
• The animal models are predictive of humans

29
Example 3 Step 1 Model development

• Nanoparticles of varying sizes will be used in
  this study.
• e.g. 10 nm, 30 nm, 80 nm, 150 nm, 200 nm, 400 nm
• Nanoparticle (containing radiolabel) will be
  administered to rats by bolus IV administration
• Rats (N3) will be sacrificed at selected
  timepoints and analyzed by QWBA
• The exposure to the nanoparticle in particular
  organs will be determined
• Urine and feces will be collected for
  quantitation of amount of nanoparticle excreted

30
Example 3 Step 1 Model development

• Study could also include microautoradiography
  and/or confocal microscopy in order to determine
• Distribution within a given tissue
• Uptake into cells
• Alternative study design could replace
  autoradiography with tissue excision and
  radioactivity determination (by LSC or AMS)

31
Example 3 Step 1 Model development

• Rationale
• Rats will be used since it is a standard species
  used to assess the teratogenicity of NCEs
• By using the rat, we will be able to generate
  data that can be relevant to the risk assessment
  of the safety of a nanoparticle that will be used
  as a therapeutic
• IV administration is the most common route of
  administration for nanoparticle based
  therapeutics

32
Example 3Step 2 Method Validation

• A nanoparticle (differing in composition to that
  used in step 1) will be produced at two different
  sizes (e.g. 80 nm and 150 nm)
• The distribution and excretion of the particle
  will be determined as described in Step 1

33
Example 3Step 3 Method Translatability

• A nanoparticle of a fixed composition and of two
  different sizes (e.g. 80 and 150 nm) will be
  administered to rabbits
• The distribution and excretion of the particle
  will be determined as described in Step 1
• The rabbit has been selected as the second test
  species based on its use in the assessment of
  teratogenicity of NCEs

34
Example 3Data Interpretation

• It should be noted that the observation that a
  nanoparticle crosses the placental barrier does
  not necessarily mean that toxicity will be
  observed in the fetus
• However, if the nanoparticle does not cross the
  placental barrier, the possibility of toxicity is
  low
• If the nanoparticle is not stable, the data
  generated will represent the distribution of the
  intact nanoparticle and/or its metabolites/degrada
  tion products
• Assessment of the uptake into cells will be
  required for full data interpretation

35
Example 4

• Which diseases may be amenable to being treated
  with non-targeted nanoparticle based drugs?

36
Example 4Objective

• To determine the distribution of nanoparticles of
  different diseased tissues

37
Example 4Assumptions

• Size is the major driver of the distribution of a
  nanoparticle
• The type of nanoparticle (liposome, dendrimer
  etc) does not impact the distribution of the
  nanoparticle
• The size of the nanoparticle does not change with
  time in vivo
• The nanoparticles do not degrade (i.e. are
  stable) in vivo
• Incorporation of a drug in, or conjugation of a
  drug to, a nanoparticle does not change its
  physical properties or distribution
• Concentrations of nanoparticle can be determined
  accurately in tissue samples
• The nanoparticle will be administered
  intravenously (most common route of
  administration to date)

38
Example 4Evaluation in humans

• Nanoparticles of one or more size (e.g. 10, 80
  and150 nm) will be used in this study
• The nanoparticle will contain an imaging or
  contrast agent
• A microdose of the nanoparticle will be
  administered to different groups of human
  volunteers, including
• Cancer patients
• Rheumatoid arthritis patients
• Atherosclerosis patients
• Normal Healthy Volunteers (see Example 1)
• The distribution of the nanoparticles will be
  determined using imaging
• Since microdose levels of nanoparticles will be
  administered, the clinical trial could be
  conducted under an Exploratory IND rather than a
  traditional IND

39
Example 4Data Interpretation

• It should be noted that the observation that a
  nanoparticle distributes to a particular tissue
  does not necessarily mean that toxicity will be
  observed in that particular tissue or that the
  nanoparticle will be efficacious
• However, if the nanoparticle does not distribute
  to a given tissue, the possibility of toxicity
  and/or efficacy is low
• If the nanoparticle is not stable, the data
  generated will represent the distribution of the
  intact nanoparticle and/or its metabolites/degrada
  tion products