Toxicology in Drug Development Lynnda Reid, Ph.D. Pharmacology/Toxicology Reviewer Center for Drug Evaluation and Research (CDER) Rafael Ponce, Ph.D., DABT Senior Scientist ZymoGenetics, Inc.

Outline Regulatory Overview Drug/biologic development process Resources Questions (and answers?)

Parties involved in Drug Development FDA Sponsor Contract Labs Clinical Sites Manufacturing Sites Consultants Other…

Sponsors Pharmaceutical/Biotechnology Firms Practicing Physicians and Dentists Academic Institutions NIH Other

The FDA Center for Drug Evaluation and Research (CDER) Center for Biologic Evaluation and Research (CBER) Center for Devices and Radiological Health (CDRH) Center for Veterinary Medicine (CVM) Center for Food Safety and Applied Nutrition (CFSAN) National Center for Toxicological Research (NCTR) Office of Regulatory Affairs

Drug Center for Drug Evaluation and Research (CDER) Conventional synthetic chemicals Antibiotics, natural and recombinant hormones Novel drugs such as antisense oligonucleotides and synthetic peptides (< 40 AA)

Biologic Center for Biologics Evaluation and Research (CBER) Blood and blood products Vaccines and allergenics Conventional biotechnology-derived products recombinant proteins, monoclonal antibodies, antigenic peptides Novel biotechnology-derived products cellular or gene therapies, tissue-engineered therapies DNA vaccines, xenotransplantation

Proteins Small Molecules

CDER Review Divisions Anesthetic, Critical Care, and Addiction Anti-Viral Anti-Infective Anti-Inflammatory, Analgesic, and Ophthalmic Cardio-Renal Dermatologic and Dental Gastrointestinal and Coagulation Metabolic and Endocrine Medical Imaging and Radiopharmaceutical Neuropharmacological Oncology Over-the-Counter Pulmonary Reproductive and Urologic Special Pathogens and Immunologic

What Types of Nonclinical Studies Should Sponsors Conduct? ICH (International Conference on Harmonization) Guidelines Drug class specific guidance FDA Consultations General toxicity? Genotoxicity? Carcinogenicity? General Toxicology? Genotoxicity? Carcinogenicity?

Guidance, Guideline, or Regulation A guidance and a guideline are the same. Provide direction and a course(s) of action Not legally binding Public comments are considered, but responses are optional Regulation A rule or a law by which conduct is governed Legally binding Published through notice and rulemaking, e.g., CRF, FR Substantive public comments MUST be responded to in the preamble of the final rule

The ICH Process Established in 1990 to improve efficiency of the new drug approval process in Europe, Japan, and the United States Regulators and industry representatives from all three regions participated The harmonized topics are safety, quality, and efficacy

ICH Nonclinical Guidance Topics Nonclinical safety studies for pharmaceuticals Timing of nonclinical safety studies Phase 1 studies (2) Pharmacokinetics Safety Pharmacology Acute and Repeat dose toxicity studies (3) Toxicokinetics Reproductive toxicology (3) Genotoxicity (2) Carcinogenicity (4) Duration of chronic toxicity testing Biotechnology products Impurities & Stereorisomers (4)

FDA Nonclinical Guidance Topics Published Guidance Documents: Content and Format of INDs for Phase 1 Studies Single Dose Acute Toxicity Testing for Pharmaceuticals Product Specific guidance anti-virals vaginal contraceptives and STD preventatives Special Protocol Assessment Submission in Electronic Format (2) Published Draft Guidances: Carcinogenicity study protocols Immunotoxicology Photosafety testing Statistical evaluation of carcinogenicity studies

Types of Toxicology Studies Recommended General Toxicology acute and repeat dose toxicology studies Special Toxicology Studies local irritation studies, e.g., site specific, ocular hypersensitivity studies for inhalation and dermal drug products Reproductive and Developmental Toxicology Studies male and female fertility embryonic and fetal development post-natal reproductive and developmental effects

Impact of Nonclinical Studies on Drug Development Setting Initial Doses in Humans Identification of Possible Adverse Effects Identification of Reversible vs Irreversible Effects Identification of Useful Biomarkers for Monitoring Toxicity during Clinical Trials Drug Labeling

Drug Development Process PRELEAD IND NDA Investigational New Drug New Drug Application Research “Discovery” Development

Toxicology Testing Process PRELEAD IND NDA/BLA Discovery Development Nonclinical tox studies in animals Clinical trials P1 P2 P3

What are Phase 1, 2, and 3 Trials? Safety and pharmacokinetics Generally 20 to 80 subjects Closely controlled Phase 2: Efficacy and safety Usually no more than several hundred subjects Closely controlled Phase 3: Efficacy and safety Several hundred to several thousand subjects Controlled and uncontrolled

Nonclinical Information Flow In vitro/Animal Models Application Trial Hypothesis testing Mechanism of action Safety assessment Develop surrogate markers ADME/PK Potential for effect Toxicity profile Dose/regimen Route of administration J. Lipani, 1998

Contract Research Organizations Formulation/Manufacture/Fill and Finish Metabolism/distribution (ADME/PK) In vitro Activity/high throughput screening Toxicity (non-GLP and GLP) In vivo Research Model development Proof of concept/efficacy Development GLP toxicology testing for regulatory submission

Good Laboratory Practice (GLP) for Nonclinical Laboratory Studies 21 CFR Part 58 Regulatory guidelines for conduct of toxicology (safety) studies in support of regulatory submission Guidelines “intended to assure the quality and integrity of the safety data…”

GLP Overview Cover food additives, human and animal drugs, biologics, devices, and electronics Define terms Define responsibility of facility management, study director, quality assurance unit Describe facility requirements Animal care, test/control articles, lab operations, specimen and data storage, equipment, SOPs, records, etc.

Toxicology CRO Independent research facility Specialized facility designed to meet Animal care requirements (Dept. of Agriculture) Quarantine requirements (CDC) Facility/study GLP requirements (US FDA) Safety and health regulations (OSHA, state, region) Provide general or specialized testing Discovery Development (GLP toxicology testing for regulatory submission)

Study Director Responsible to Sponsor, Facility, FDA Single point of control Responsible for overall technical conduct of study Interprets, analyzes, documents, and reports results SD does not necessarily conduct all aspects of these activities, but has ultimate responsibility

Study Director Often, but not always, a toxicologist Often, but not always, MS or PhD (depends on experience) DABT or equivalent a plus – marketable

Types of Nonclinical Studies Reviewed by FDA Basic pharmacology primary and secondary mechanisms of action nonclinical efficacy studies Safety pharmacology Pharmacokinetics Toxicology Genotoxicology Carcinogenicity

What Does FDA Expect from Nonclinical Studies? Pharmacology proposed mechanism of action identification of secondary pharmacologic effects Proof of Concept studies for serious indications Safety Pharmacology effects on neurological, cardiovascular, pulmonary, renal, and gastrointestinal systems abuse liability

What Does FDA Expect from Nonclinical Studies? Pharmacokinetics comparison of ADME in species used for toxicology studies identification of bioaccumulation potential identification of potential differences in gender generation of PK parameters, e.g., Cmax, Tmax, AUC(o-inf.), half life

What Does FDA Expect in General Toxicology Studies? Acute and repeat toxicology studies in two species Duration of repeat dose nonclinical studies should be at least equal or greater than the duration of the proposed clinical study A control and at least 3 drug concentrations identification of the NOAEL and MTD identify shape of the dose-response curve Doses/systemic exposure should exceed clinical dose/exposure

What Does FDA Expect in General Toxicology Studies? Formulation should be the same as the clinical formulation Route of exposure: should be the same as clinical route additional routes of exposure may be needed to achieve systemic toxicity Histopathology examination of all animals and standard tissues Lymphoproliferative tissues should be assessed for unintended effects on the immune system Toxicokinetic information

Timing of Nonclinical Studies - Phase 1 Prior to “First Time in Humans” safety pharmacology pharmacokinetics/toxicokinetics (exposure data) single dose toxicity studies in 2 mammalian species expanded acute or repeat dose toxicity studies in a rodent and a nonrodent local tolerance in vitro evaluation of mutations and chromosomal damage hypersensitivity for inhaled and dermal drugs teratogenicity studies

Timing of Nonclinical Studies - Phase 1/2 Phase 1-2 Clinical Trials repeat dose toxicity studies of appropriate length Phase 2 Clinical Trials complete genotoxicity assessment (in vivo and in vitro)

Timing of Nonclinical Studies - Phase 3 Phase 3 Clinical Trials repeat dose toxicity studies of appropriate length male and female fertility post-natal development

Acute dose range finding in rats 10 rats (5M/5F) Control + 4 Dose groups Single exposure, IV Monitor clinical observations, food consumption, serum chemistry, hematology, coagulation over 7 days (+ baseline) Serum PK Gross observations, histopathology on major organs and tissues

Chronic GLP Tox in Cynos 32 cynomolgus nonhuman primates (16M/16F) Control (5M/5F), Low (3M/3F), Med (3M/3F), High (5M/5F) Repeated exposure over 4 weeks, Sac 3M/3F, 4 week recovery Monitor clinical observations, food consumption, serum chemistry, hematology, coagulation over 56 days (+ baseline) Monitor PK, antibody formation Gross observations, histopathology on major organs and tissues Include other clinical endpoints as appropriate (EKG, ophthalmology, BP) Perform specialty testing on tissues/blood (immunohistochemistry, FACS)

Questions Asked by Review Pharmacologist/Toxicologist Validity of study design: Was the appropriate animal model used? Were dose(s) and duration sufficient to support the proposed clinical study or labeling? Were adequate systemic exposures achieved? Was the route of administration relevant to clinical used?

More Questions: Did the test system exhibit any effects? Were the effects treatment-related? Are the effects biologically significant? Are the effects reversible? Are the effects clinically relevant? Can the effects be monitored clinically?

Career Opportunities for FDA Toxicologist Pre-IND Consulting Review nonclinical protocols Serve on intra- and inter-agency expert working committees Generate guidance and policy documents Professional development

For Online Information on FDA http://www.fda.gov/ CDER News Guidelines ICH Documents Employment Opportunities