CONFIDENTIAL

Navigating Challenges in Developmental and Reproductive Toxicology (DART)

Tacey E.K. White, PhD

CONFIDENTIAL2

Outline – Navigating DART Planning

• Guideline considerations– ICH M3 (R2)– ICH S5 (R2)– ICH S6 (R1)

• Managing a DART program– Why, What and When– Case Studies: Customized DART Approach

• Special considerations for biologics– Selection of the appropriate animal model and design– Challenges when NHPs are your relevant model

CONFIDENTIAL3

Why do we conduct DART studies?

• To support enrollment of Women of Child Bearing Potential into Clinical Trials (WOCBP)

• To support the Marketing Application (NDA, BLA, etc.)

• To use understanding of the risks to reduce your company’s liability in case of unanticipated exposures during pregnancy

• To provide guidance to clinicians when prescribing to and counseling WOCBP and pregnant women (pre- and post-marketing) By populating the Pregnancy and Lactation Labeling section of

the pharmaceutical label

DART and carc – only studies that go into the label

CONFIDENTIAL4

Relevant Guidelines• ICH S5 Detection of toxicity to reproduction for medicinal products &

toxicity to male fertility – Describes what needs to be tested and some general approaches for testing.– Allows flexibility for alternative study designs

• ICH M3(R2) - Guidance on nonclinical safety studies for the conduct of human clinical trials and marketing authorization for pharmaceuticals– Describes the timing of DART studies relative to enrollment of Women of

Child Bearing Potential into clinical trials

• ICH S6 (R1) Preclinical Safety Evaluation of Biotechnology-Derived Pharmaceuticals - Addendum (R1)– Describes additional considerations for Biologicis

CONFIDENTIAL5

ICH S5(R2): Assessment of toxicity to reproduction

A. Premating to conception (adult male and female reproductive functions, development and maturation of gametes, mating behavior, fertilization).

B. Conception to implantation (adult female reproductive functions, preimplantation development, implantation).

C. Implantation to closure of the hard palate (adult female reproductive functions, embryonic development, major organ formation).

D. Closure of the hard palate to the end of pregnancy (adult female reproductive functions, fetal development and growth, organ development and growth).

E. Birth to weaning (adult female reproductive functions, neonate adaptation to extrauterine life, preweaning development and growth).

F. Weaning to sexual maturity (postweaning development & growth, adaptation to independent life, attainment of full sexual function).

CONFIDENTIAL6

ICH S5(R2): Assessment of toxicity to reproduction

A. Premating to conception (adult male and female reproductive functions, development and maturation of gametes, mating behavior, fertilization).

B. Conception to implantation (adult female reproductive functions, preimplantation development, implantation).

C. Implantation to closure of the hard palate (adult female reproductive functions, embryonic development, major organ formation).

D. Closure of the hard palate of the end of pregnancy (adult female reproductive functions, fetal development and growth, organ development and growth).

E. Birth to weaning (adult female reproductive functions, neonate adaptation to extrauterine life, preweaning development and growth).

F. Weaning to sexual maturity (postweaning development & growth, adaptation to independent life, attainment of full sexual function).

Fertility / SEG I

Embryo-Fetal DevelopmentEFD / SEG II / Teratology

Pre-Postnatal DevelopmentPPN / SEG III

CONFIDENTIAL

Standard Study Designs ICH S5(R2)

A B C D E F

Premating to Conception

Conception to Implantation

Implantation to Closure of Hard

Palate

Hard Palate Closure to End of

Pregnancy

Birth to Weaning Weaning to Sexual Maturity

Fertility Study – Rodent, N >20/groupDenotes Dosing Period

Embryo-Fetal Development Study (EFD) (2), N >20/group

Pre- and Postnatal Development Study, N >20/group

Rodent, Rabbit (NHP)

Rodent (NHP)

S. Campion, Pfizer

Mouse – GD18Rat – GD 21Rabbit – GD 29

CONFIDENTIAL

• Fertility and Early Embryonic Development Study– Mating behavior; hormonal control– Fertility– Embryonic survival prior to implantation (preimplantation loss)

• Embryo-fetal Development Study– Fetal morphology (external, visceral, skeletal)– Survival (postimplantation loss)– Growth

• Pre-/postnatal Development Study– Morphology– Survival– Growth– Function – behavior, reproductive function– Parturition and Lactation

Types of Data by Study

CONFIDENTIAL

• Control and 3 treated groups• Doses spaced to evaluated dose-response relationships

– Half-logs or 2-4 fold between doses (OECD & FDA)– Factor in toxicokinetics (TK)

• High dose – some amount of parental toxicity – not MTD– 10-15% reduction in body weight gain– 10-15% reduction in food consumption– Clinical signs– Target organ toxicity or clin path (from other studies)– Avoid excessive toxicity!!

• Low dose – NOAEL for parental and developmental toxicity• Mid dose – uniform spacing with LD and HD

Dose Selection

CONFIDENTIAL

• Hazard ID Requires Expert Interpretation• Animal studies are large

– N = 20-25 female animals/group; litter sizes = 8-15 per litter; 4 groups/study

– Total fetuses/pups = 640 – 1500 per study• Dysmorphogenesis and Mortality occur on every study (non-

treatment related)• Interpretation of treatment related effects depends on:

– Dose Response– Statistical Significance – Outside of historical control ranges – Rare Event at high dose

• Sound Data Interpretation is first step in accurate label

Hazard Identification

CONFIDENTIAL

Standard Reprotox Animal Models

Rat, Mouse or Rabbit– Female Fertility, Male Fertility, Embryo-fetal Development (EFD),

Pre-/postnatal Studies

Advantages:• Large historical control database• Large litter and sample sizes – increase power to detect rare

malformations (N = >20/group)• Short gestation period• Established study designs and techniques• Fertility assessments possible

Disadvantages:• Therapeutic may not be pharmacologically active or may illicit a

significant unwanted immune response

CONFIDENTIAL

Non-Standard Animal Models: NHP

Non-Human Primate (NHP)– Embryo-fetal Development, Pre-/postnatal Development Studies

Advantages:• Can test the clinical candidate in pharmacologically active species• Avoids generating / characterizing surrogate or homologue molecule• Similar embryo-fetal development and physiology of pregnancy

between NHPs and humansDisadvantages:• Standard Male and Female Fertility testing not practical• Standard group size is low (12-15), singleton births

– Decreased power to detect rare malformations• Very long and costly studies • Smaller historical control database

CONFIDENTIAL13

DART Study Timings: Pre-ICH M3(R2) Revision

Fertility, EFD - US

EFD, Fem Fertility - JP

M&F Fertility - EU

Drug Development Discovery Non-Clinical – FTIH Package IND

Preliminary EFD(DRF size)

EFD - EU

PPN – JP, EU, US

Phase I NDAPhase IIIPhase IIbPhase IIa

Child Bearing w/ Birth ControlJapan

EU

US

Japan, EU, US

Enrollment of Women of Child-Bearing Potential (WOCBP) into Clinical Trials

[WOCBP]IND

Male Fertility - JP

CONFIDENTIAL14

ICH M3(R2) Revisions and WOCBP Inclusion

Introduction:• “For women of childbearing potential (WOCBP) there is a high level of concern for the

unintentional exposure of an embryo or fetus before information is available concerning the potential benefits versus potential risks.”

• “It is important to characterize and minimize the risk of unintentional exposure of the embryo or fetus when including WOCBP in clinical trials.”

Two Approaches:1. Conduct reproduction toxicity studies to characterize the risk and take

appropriate precautions 2. Limit the risk by taking precautions to prevent pregnancy during clinical trials

– pregnancy testing (e.g., based on the β-subunit of HCG), – use of highly effective methods of birth control (Note 3: < 1% failure rate)– study entry only after a confirmed menstrual period– informed consent based on any known effects of structure or intended

pharmacology on reproduction or development• Also consider: Mechanism, extent of fetal exposure, type of pharmaceutical,

difficulty identifying animal model

CONFIDENTIAL15

Approaches for Including WOCBP in Clinical Trials

Short Studies (less than 14 days duration including time of exposure) • No DART studies needed

• Stringent control of pregnancy AND Informed consent on targetImminently Life Threatening

(e.g., cancer, ICH S9)

Phase II Studies (up to 3 months duration and less than 150 WOCBP)

• Preliminary DART studies in 2 species (N=6, GLP recommended)

• Control of pregnancyPhase III Studies or larger and longer Phase II studies

• Pivotal EFD (SEG II) studies in 2 species

• Control of pregnancy as appropriate

Note: Some flexibility for compounds with limited exposure and/or limited animal models: For example, for mAbs with 3rd trimester exposure only, could conduct studies during Phase III and submit to support marketing.

CONFIDENTIAL16

Preliminary DART Study Designs• Conduct in 2 species where possible (rat & rabbit preferable)• N=6 pregnant females per group• GLP conditions recommended• Fetal exams on 100% of fetuses/litter:

– External – Visceral

• Caveat: This study design is not powered to detect rare malformations. Best for detecting maintenance of pregnancy or embryo-fetal survival.– May be risky if developmental toxicity would contribute to

Go/No-Go decision– Use target biology information to guide decision

CONFIDENTIAL17

ICH M3 (R2) – Female Fertility Study Timing

• “WOCBP can be included in repeated-dose Phase 1 and 2 trials prior to the conduct of the female fertility study since an evaluation of the female reproductive organs is performed in the repeated dose toxicity studies (Note 2).”

• Female fertility studies should be completed to support Phase 3 trials• “Note 2: An assessment of male and female fertility by thorough standard

histopathological examination of the testis and ovary in a repeated dose toxicity study (generally rodent) of at least 2-week duration is considered to be as sensitive as fertility studies in detecting toxic effects on male and femalereproductive organs (Refs. 11, 14, 15).”– ICH Assumption: female fertility hazards can be predicted by changes to

female reproductive organs in the general toxicity studies

• Personal Experience: Target biology more predictive than general tox for female fertility signal

CONFIDENTIAL18

DART Study Timings: ICH M3 R2

• More harmonized, but also more options!• How do we decide which approach to take?

Drug Development Discovery Non-Clinical IND

Phase I Phase IIa NDAPhase IIIPhase IIb

EFDs, M & F Fertility PPN – JP, EU, US

M & F Fertility

[WOCBP]

EFD

Prelim. EFD in 2 species

IND

CONFIDENTIAL19

Designing a Fit-For-Purpose DART Package

• Consider the following questions:– When will I enroll WOCBP and what percentage of the study will

they comprise?

– What is my patient population?

– Will developmental toxicity factor into a Go/No-Go decision for my drug?

– Do I have concerns for developmental toxicity based on my therapeutic mode of action (pharmacology target activity)?

CONFIDENTIAL20

Example: α4 Integrin (VLA-4) Inhibitor

• Background– α4 Integrins regulate cell-ECM and cell-cell adhesions by binding to

fibronectin and VCAM-1 – Exist as heterodimers: α4/β1 or α4/β7

• α4 Knockout mouse (Yang et al., Development, 121:549-80, 1995)– Homozygotes: Embryolethality at 2 embryonic times

• E9.5 – E11.5: Failure of allantois and chorion to fuse• E12.5 – E14.5: Heart, cranial and facial defects

– Heterozygotes: No obvious defects, fertile, normal through at least 1 year old

• Therefore: An α4 Integrin inhibitor has the potential for causing developmental toxicity– Dependent on extent, duration of inhibition, etc.

CONFIDENTIAL21

Results of DART w/ Three α4 Integrin Inhibitors(Crofts et al., BDR-B, 71:55-68, 2004)

Drug/Doses

Maternal Toxicity

Embryo-lethality Fetal Defects

Rabbit NOAEL(mg/kg/day)

IVL74510, 50, 250

- - - 250

HMR10315, 20, 75

- Minor skeletal variations, lower fetal weight

20

IVL9840.2, 1, 5, 15

Cardiovascular and sternebral malformations

< 0.2

• Malformations were consistent with pharmacology-related effects as observed in knockout mice

• α4 Integrin inhibitors had variability in response• Variability could be considered consistent with prediction, where a

50% decrease in α4 Integrin still supported normal development• Are differences related to TK, target affinity, extent of inhibition?

CONFIDENTIAL

Case Studies:Customized DART Approach

CONFIDENTIAL23

Designing a Fit-For-Purpose DART Package

• Consider the following questions:– When will I enroll WOCBP and what percentage of the study will

they comprise?

– What is my patient population?

– Will developmental toxicity factor into a Go/No-Go decision for my drug?

– Do I have concerns for developmental toxicity based on my therapeutic mode of action (pharmacology target activity)?

CONFIDENTIAL24

Example 1 – Rheumatoid Arthritis Drug

• Mode of Action: Reduces cytokine X levels• Target Information: Cytokine X KOs and Cytokine X receptor KOs

– Born in expected mendelian ratios– No obvious developmental defects– Offspring survive to adulthood and reproduce normally

• Patient Population:– Older individuals with a smaller number of WOCBP

• Clinical Plan: Phase 2 clinical trials, 2 months duration • Developmental Tox Tolerance: High

– Gold standard has developmental tox liability– A significant segment of the patients are older– Good treatments are lacking

CONFIDENTIAL25

Example 1 – Rheumatoid Arthritis Drug

Drug Development Discovery Non-Clinical IND

Phase I Phase IIa NDAPhase IIIPhase IIb

EFDs, M & F Fertility

WOCBP

Prelim. EFD in 2 species

IND

Recommendation: • Could support WOCBP with preliminary studies and conduct

definitive EFD and Fertility studies after POC

CONFIDENTIAL26

Example 2 – Depression Drug

• Mode of Action: Antagonist of brain receptor (BR)• Target Information: BR KO

– Homozygous – embryolethal– Heterozygous – no developmental abnormalities; minor effects on

fertility parameters– Therefore, potential for developmental and reproductive toxicity

• Patient Population:– Primarily WOCBP

• Developmental Tox Tolerance: Low– WOCBP main patient population– Many other depression drugs already on the market

CONFIDENTIAL27

Example 2 – Depression DrugRecommendation:• Conduct Definitive EFD studies to support WOCBP• Consider Female Fertility during Phase IIa to avoid delay of Phase III.• Could consider WOCBP in Phase I if that were desirable – plan short

duration study with careful control of pregnancy

Drug Development Discovery Non-Clinical IND

Phase I Phase IIa NDAPhase IIIPhase IIb

M & F Fertility

WOCBP

Definitive EFDs

IND

Short duration WOCBP

CONFIDENTIAL

Special Considerations for Biologics: ICH S6(R1) and ICH M3(R2)

Examples of Alternative Study Designs

CONFIDENTIAL29

Types of Biotherapeutics• Monoclonal Antibodies (can inhibit or activate a target)

– Mouse, chimeric, humanized, whole or fragments, etc.• Cytokines and Growth Factors

– Interferons, interleukins, colony stimulating factor

• Hormones– Growth hormone, insulin, erythropoietin

• Vaccines– Proteins or peptides, DNA plasmids

• Gene and Cell Therapy products– Viral and non-viral delivery systems,

genetically engineered cells, stem cells• Blood products

– Albumin, thrombolytics, fibrinolytics, clotting factors

Cavagnaro (2002) Nature Reviews Drug Discovery, 1:469-475

CDER

CBER

CONFIDENTIAL30

Types of Biotherapeutics• Monoclonal Antibodies (can inhibit or activate a target)

– Mouse, chimeric, humanized, whole or fragments, etc.• Cytokines and Growth Factors

– Interferons, interleukins, colony stimulating factor

• Hormones– Growth hormone, insulin, erythropoietin

• Vaccines – Separate Guideline– Proteins or peptides, DNA plasmids

• Gene and Cell Therapy products– Viral and non-viral delivery systems,

genetically engineered cells, stem cells• Blood products

– Albumin, thrombolytics, fibrinolytics, clotting factors

Cavagnaro (2002) Nature Reviews Drug Discovery, 1:469-475

CDER

CBER

CONFIDENTIAL31

Differences Between Biopharmaceuticals(Large Molecules) and Small Molecules

Small Molecules (sce’s)• Small: < 700 daltons• Generally lipophilic - Can cross

biological membranes, including the placenta and/or VYS

• Well defined structures and relatively stable

• Rapidly metabolized; require daily dosing

• Toxic response related to chemical structure and exaggerated pharmacology

• Less likely to illicit an immune response (be immunogenic)

• More likely to have activity in multiple species

Biopharmaceuticals• Large Macromolecules:

– Peptides – ~ 1,000 to 10,000 dal– Proteins – ~ 20,000 to 60,000 dal– mAbs - ~150,000 dal

• Less lipophilic - Generally either can’t cross the placenta or use receptor-mediated mechanisms

• Complex physiochemical characteristics and heat sensitive

• Degraded over time, can be very long acting; may need intermittent dosing

• Toxic response related to exaggerated pharmacology

• More likely to be immunogenic• More often show species

selectivity Cavagnaro (2002) Nature Reviews Drug Discovery, 1:469-475

CONFIDENTIAL32

Considerations for Selecting an Appropriate Animal Model and Study Design for Biologics

• Pharmacologic Activity– Toxicity based on chemical structure not expected, so a

pharmacologically relevant species is a must– mAbs, cytokines and growth factors, etc. – should cross-react with the

appropriate target in the animal species– The pharmacologic target should have a similar function in the animal– Vaccines should elicit an appropriate immune response

• Immunogenicity– Are neutralizing antibodies (NAs) formed?– Would an immune response be elicited that would significantly impact

the health or survival of the animal?

• Toxicokinetics– If NAs exist, can we still maintain adequate exposure?– Would biologic be expected to reach the embryo/fetus?– Are there likely to be species differences?

CONFIDENTIAL33

ICH S6 (R1) AddendumGeneral Principles:• Reprotox should be conducted only in pharmacologically relevant

species• When the clinical candidate is pharmacologically active in

rodents and rabbits, these species should be used unless there is a scientific reason to use a NHP– Follow ICH M3– One species generally sufficient if only one is relevant – Should justify the choice of species

• Preference for testing the clinical product over the rodent homologue• Specific study design can be modified based on immunogenicity,

exposure, etc.• Timing is also flexible – studies with mAbs can be done during

Phase III – Use target biology

CONFIDENTIAL34

5.3 Embryo-Fetal (EFD) and Pre/Post-Natal Development (PPND) Fertility

For products pharmacologically active only in NHPs, several study designs can be considered based on intended clinical use and expected pharmacology. Separate EFD and/or PPND studies, or other study designs (justified by the sponsor) can be appropriate, particularly when there is some concern that the mechanism of action might lead to an adverse effect on embryo-fetal development or pregnancy loss.

However, one well-designed study in NHPs which includes dosing from Day 20 of gestation to birth (enhanced PPND; ePPND) can be considered, rather than separate EFD and/or PPND studies.

ICH S6 (R1) – NHP only relevant species

CONFIDENTIAL

IgG Placental Transfer in NHPs

Cynomolgus Data from Fujimoto et al., 1983 Slide Courtesy of Gary ChellmanRhesus Data from Coe et al., 1993 CRL - Nevada

CONFIDENTIAL

Transfer of IgG to the Conceptus in Primates

CONFIDENTIAL37

ePPND Study

• No Caesarian section but offspring is being evaluated– Viability, external evaluation, skeletal (e.g. X-ray), visceral at necropsy– An interim report (see Note 6) for data to Day 7 post-partum for all

animals is called for to support Phase III

• Ultrasound for tracking pregnancy maintenance but not appropriate for detecting malformations

• Postnatal dosing of the mother is generally not recommended

• Postnatal phase duration is dependent on relevant endpoints (Note 4)

• Group sizes should allow meaningful interpretation of data (Note 5)

ICH S6 (R1)

CONFIDENTIAL38

ICH S6 (R1) 5.2 Fertility

• When the nonhuman primate is the only relevant species:

• Potential for effects on male and female fertility can be assessed by evaluation of the reproductive tract (organ weights and histopathological examination) in repeat dose toxicity studies of at least 3 months duration using sexually mature NHPs.

– Need for sexually mature NHPs in general toxicity evaluation– Handling, social housing of mature, larger NHPs

• Sperm analysis, reproductive hormones, menstrual cycle monitoring: only if there is a specific cause for concern

• Study duration of 6 months in a repeat toxicity study is considered sufficient

CONFIDENTIAL39

ICH M3(R2): Additional Considerations for Studies in WOCBP

• Knowledge of the mechanism of action of the agent • Type of pharmaceutical agent• Extent of fetal exposure • Difficulty of conducting developmental toxicity studies in an

appropriate animal model

• For example: For monoclonal antibodies for which embryo-fetal exposure during organogenesis is understood to be low in humans …. the developmental toxicity studies can be conducted during Phase III (support marketing)

• ICH S6 Addendum: Timing and species selection depends on exposure during embryo-fetal development

• But – is exposure the whole story?

CONFIDENTIAL40

Maternally Mediated Developmental ToxICH S5: • B. Conception to implantation (adult female

reproductive functions, preimplantation development, implantation).

• C. Implantation to closure of the hard palate (adult female reproductive functions, embryonic development, major organ formation).

• D. Closure of the hard palate to the end of pregnancy (adult female reproductive functions, fetal development and growth, organ development and growth).

CONFIDENTIAL41

Maternally Mediated Developmental Toxicity• Placental Toxicity• Altered Nutritional status• Decreased uterine blood flow, anemia, hypoxia• Toxemia• Autoimmune states and Immune alterations

– ex, Interferon• Diabetes and hypoglycemia• Acid-base disturbances

From: Daston, in: Developmental Toxicology, Raven Press, 1994

Warning: Don’t forget about Intended Pharmacology and Maternal Factors!!

CONFIDENTIAL

Case Studies:Biologic Compounds

CONFIDENTIAL43

Example 3: mAb 1000• Therapeutic: Humanized mouse IgG (monoclonal Ab)

against protein 1000– Very long biological half-life in rats and NHPs– Cross-reacts with rat and rabbit target

• Target biology assessment:– No target concerns for fertility

• Recommended: Use rat and rabbit for DART

• Step 1: Use Rabbit DRF study to determine dose intervals and immunogenicity potential

• Rabbit Dose-Range– Dose based on T1/2 in other species– Verify exposure and dosing regimen– Look for anti-drug antibodies (ADAs) at end of gestation

CONFIDENTIAL44

Rabbit DRF Plasma Curves

50 mg/kg

5 mg/kg

0.5 mg/kg

168243624

Time (hrs)

0.01

0.1

1

10

100

1000

10000

Plas

ma

Con

cent

ratio

n (µ

g/m

L)

168 36

↓ dose 2↓ dose 1

3 3

ADAs

CONFIDENTIAL45

Example 3: mAb 1000Results:• Rabbit Dose-Range

– Toxicokinetics showed long half life – supports weekly dosing– Immunogenicity: Anti-drug antibodies were produced BUT they

are manageable

Recommended Definitive Study Designs:• Rabbit EFD

– Once weekly dosing: GD 7, GD13

• Rat Combined Female Fertility and EFD– No target concerns support a combined study– Dose once weekly: Days 1, 8, 15 (first day of mating), and Day 6

& 13 pc– Advantage: Less expensive and fewer animals used.

CONFIDENTIAL46

Example 4: Recombinant Protein, RP-5000• RP-5000:

– Daily Dosing required– Pharmacologically active in rodents (mice) but not

rabbits– Immunogenic in mice

• Neutralizing Abs are formed• Adequate exposure only through 14 daily doses all doses• Marked reduction in exposure after longer dosing intervals

• Recommendation– Conduct DART studies in mice only– Modify study designs to ensure exposure during

critical periods

CONFIDENTIAL47

RP-5000 Reprotox Studies• Female Fertility and Early Embryonic Development Study

– Divided into two phases

Study 1: Fertility• Limit mating to 1 week• Dose up to 14 days

Study 2: Early Embryo Devel• Start dosing on GD0• Dose 7 days

Mating Start Mid Gestation C-section

Day -7 Confirmed Mating Day (GD0)

Dosing

GD 0

Dosing

GD 7 Mid Gestation C-section

CONFIDENTIAL48

RP-5000 Reprotox Studies in Mice

Day 6 pcDay 0 pc Day 15 pc

C-section Day 18 pc

Dosing

Day 0 pc Day 15 pc

Parturition

Dosing

Weaning

PP Day 10

Study 3: Standard EFD• 10 daily doses

Study 4: Modified PPN• 14 daily doses

Note: RP-5000 unlikely to cross the placenta or VYS (MW > 60kdal), this justifies late gestational dosing regimen.

CONFIDENTIAL

Example 5: Immuno-modulatory mAb: GSK- mAb-9000

• GSK-mAb-9000– Humanized mAb against a cytokine– Does not cross-react with rodent– No rodent homologue available– mAb alters the immune response, so postnatal

immune assessments are desired

• Approach:– Conduct Primate Combined ePPND study

CONFIDENTIAL

Cycle checks

GD0

Mating

GD18-20

Pregnancyconfirmation

= Treatment / Pregnancy Monitoring

= Nursing / Behavior / Immune Assessments

GD160

Delivery• external exams

• skeletal exams (X-ray)• nursing behavior

• early developmentallandmarks

PPD 90-135

Infant Necropsy• Visceral exams•Immune assessments

Example 5 – ePPND study mAb-9000

CONFIDENTIAL51

Conclusions• DART studies are conducted to support enrolling WOCBP into

clinical trials and for marketing, but also to council women after unintended exposures

• Flexibility exists in the timing and types of studies needed• Deciding on the timing and design of DART studies should

take into account:– Patient population, clinical development program– Target biology (Mode of action)– Likelihood that DART would factor into Go/No-Go decision

• Specialty pharmaceuticals, such as biologics, have special considerations based on species specificity, immunogenicity and toxicity related to exaggerated pharmacology, which could require additional study design modifications

CONFIDENTIAL

Backups

52

CONFIDENTIAL

Reproductive Toxicology Studies with Vaccines

CONFIDENTIAL54

Applicable Guidelines• FDA (CBER) Guidance for Industry: Considerations for

Developmental Toxicity Studies for Preventive and Therapeutic Vaccines for Infectious Disease Indications, February 2006– Applies to vaccines for infectious diseases which are intended to

be given to WOCBP or pregnant women– Not applicable to therapeutic vaccines against mammalian

targets • World Health Oranization: Guidelines on Nonclinical Evaluation of

Vaccines, 2003• International Conference on Harmonization, ICH S5A: Detection

of Toxicity to Reproduction for Medicinal Products and Toxicity to Male Fertility, 2005

• Note: FDA and WHO guidelines are in general agreement, so only differences are noted.

CONFIDENTIAL55

When Developmental Toxicity Studies are Needed

• Women of Child Bearing Potential (WOCBP)– Can be enrolled in clinical trials prior to DART studies– Need to include appropriate contraceptive use– Developmental toxicity assessment needed for marketing

application• Pregnant Women

– Developmental toxicity assessment needed prior to enrolment into clinical trials

• Pediatric Only– No Developmental toxicity assessment needed for clinical trials

or for marketing

CONFIDENTIAL56

Developmental Tox Study Design Considerations

• Most concern is for effects on developing embryo/fetus and for early postnatal development

• Study Design– Evaluation of effects from implantation through closure of the hard

palate and through weaning (ICH S5 Stages C,D,E)– Single study with subgroups:

• One subgroup taken for c-sections (e.g., N=20)• One subgroup allowed to deliver and pups develop through weaning (e.g.,

N=20)– Post-weaning or fertility assessments generally not required

• Animal Model– Must mount an immune response to the vaccine– Immune response need not be identical to human– Single species generally acceptable

CONFIDENTIAL57

Dev Tox Study Design, continued• Dose and Dosing Regimen

– Use clinical formulation and lot when possible– Single clinical dosage level (absolute) recommended

• Alternatively: > human dose (mg/kg) with peak Ab response– Control Group and Active Control (with adjuvant) recommended– Dosing regimen should provide peak exposure of Maternal Ab response

during key developmental stages• Note: 1-2 doses given prior to mating may be necessary to achieve peak PD

response during organogenesis• May need to dose-range to characterize Ab response

• PD Confirmation– Confirmation of passage of Maternal Ab to fetus recommended, i.e.,

testing of fetal blood– FDA also recommends postnatal passage of Abs, i.e., testing of pup

blood

CONFIDENTIAL58

Fertility and Embryofetal Endpoints• Maternal:

– Standard clinical obs, body weight, food consumption, etc.– No specific mention of estrous cyclicity, but could be a good measure of

reproductive capability– Standard necropsy with collection of gross obs for possible followup

histopath– Standard c-section endpoints (first subgroup) (live, dead, resorbed

fetuses; CLs)• Fetal (one subgroup)

– Standard fetal weight and external, visceral (internal confirmation of sex), skeletal evaluations

– Note: there is mention of examining late resorptions, dead fetuses and aborted fetuses to the extent possible (different from our standard)

CONFIDENTIAL59

Postnatal Endpoints

• Maternal (F0):– Second subgroup (e.g., N=20) allowed to deliver– Evaluate standard indices, e.g., gestation, postnatal viability, fertility, etc.– F0 maternal necropsy at weaning: collection of tissues with gross obs and

implantation data to calculate fertility index

• F1 Offspring:– Rear through weaning– Standard observations of growth, body weight gain and nursing activities

• No mention of developmental landmark assessments– Note: some measure of “normal neuro-development (e.g., auditory and

visual tests)”• Could include automated startle on a subset at weaning• Could include eye opening plus pupillary response on PND21• No other mention of behavioral indices such as LMA or learning and memory

– F1 Necrospy: full necropsy; record abnormalities on live and dead pups

CONFIDENTIAL60

Immune Endpoints

• Requirement to confirm antibody response in the mother and passage of those antibodies to the fetus by assessment of:– Maternal Abs pre-dosing, at c-section and at weaning (minimum)– Fetal Abs in cord blood (serum) at c-section– Abs in pup serum at weaning

• Ab assessments are intended to confirm pharmacology not to assess immunotoxicity

• Additional immune endpoints may be necessary based on pharmacology of vaccine (e.g., a particular vaccine induces a cytokine which could affect pregnancy).

CONFIDENTIAL61

Adjuvant and Excipient Considerations

• Adjuvants may cause their own toxicity • Novel adjuvants and excipients require full toxicity testing separate

from the vaccine testing as for novel chemical entities• For DART studies, may be advisable to evaluate an adjuvant plus

vehicle control group in addition to a vehicle only control group

• Consultations: Remember to ask about novel adjuvants

CONFIDENTIAL62

Conclusions• DART studies are conducted to support enrolling WOCBP into

clinical trials and for marketing, but also to council women after unintended exposures

• Flexibility exists in the timing and types of studies needed• Deciding on the timing and design of DART studies should take into

account:– Patient population, clinical development program– Target biology (Mode of action)– Likelihood that DART would factor into Go/No-Go decision

• Specialty pharmaceuticals, such as biologics, have special considerations based on species specificity, immunogenicity and toxicity related to exaggerated pharmacology, which could require additional study design modifications