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Preclinical safety data for “first in human” (FIH) clinical trials in healthy volunteer subjects Oncology Drug Advisory Committee. David Jacobson-Kram, Ph.D. DABT Office of New Drugs Center for Drug Evaluation and Research Food and Drug Administration March 13, 2006.
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Preclinical safety data for “first in human” (FIH) clinical trials in healthy volunteer subjectsOncology Drug Advisory Committee David Jacobson-Kram, Ph.D. DABT Office of New Drugs Center for Drug Evaluation and Research Food and Drug Administration March 13, 2006
What preclinical safety data are required prior to giving a new chemical to human beings for the first time – and why • Most phase 1 studies are performed in healthy volunteers. No risk vs. benefit calculation, only risk assessment.
Preclinical studies define potential toxicities • What is initial safe starting dose? • What is a safe stopping dose? • What organs/systems are at risk? • Are toxicities monitorable in the clinic? • Are toxicities reversible? • Is the chemical potentially carcinogenic?
Minimal data set to begin a phase 1 clinical trial in healthy volunteers • Toxicity studies in two species (rat, dog for small molecules, often nonhuman primate for biologics) with the highest dose demonstrating a “maximum tolerated dose” (MTD) and a lower dose demonstrating a “no adverse effect level” (NOAEL). • Single dose clinical study can be supported by single dose animal studies. • Animals dosed once and sacrificed early (24 – 48 hours) and second group after 14 days.
Minimal data set to begin a phase 1 clinical trial in healthy volunteers • Repeat dose toxicity study is more efficient and cost effective (14 – 28 days). • Enables repeat dose clinical trials • Fewer animals are used, but more drug. • Inclusion of recovery group is useful in case toxicities are seen.
Typical endpoints in toxicology study: in-life • Clinical signs, behavior • Food consumption • Body weights • Clinical pathology (in larger species)
Typical endpoints in toxicology study: post-life • Macroscopic observation at necropsy • Organ weights • Clinical pathology • Hematology • Clinical chemistries • Histopathology, all organs • Toxicokinetics
Safety pharmacology • Cardiovascular (non rodent) • Blood pressure • Heart rate • ECGs • Rhythm and morphology • Arrhythmia analysis • Interval analysis including QT interval calculation
Safety pharmacology • CNS (rodent functional observation battery, Irwin test) • Spontaneous locomotor activity • Motor coordination • Proconvulsive effects • Analgesic effects • Pulmonary (rodent, plethysmography) • Minute volume • Tidal volume • Respiratory rate
Genetic toxicology • Bacterial reverse mutation assay (Ames test, measures induction of point mutations e.g. base substitution, frame shifts) • In vitro assay for chromosomal damage in cultured mammalian cells (metaphase cell analysis or mouse lymphoma gene mutation assay). • In vivo test for chromosomal damage (rodent micronucleus test, not required but often performed).
Exploratory INDs Exploratory IND Used to select drug candidate Exp IND closed, Traditional IND opened NDA or BLA
Exploratory INDs (expIND) • January 06 FDA published guidance on expIND. • expIND intended to make drug development more efficient by expediting early phase 1 clinical trials • Gain an understanding between a specific mechanism of action and the potential treatment of a disease • Provide information on PK • Select the most promising lead candidate from a group designed to interact with a specific human target, e.g., imaging studies
Exploratory INDs (expIND) • Clinical studies have no therapeutic intent, this is simply a method for choosing the most promising drug candidate • When a lead compound is selected, the expIND is closed and the drug development proceeds along the traditional pathway.
Use of exploratory INDs (ExpINDs) in improving efficiency of drug development • “The toxicology evaluation recommended for an exploratory IND application is more limited than for a traditional IND application. The basis for the reduced preclinical package lies in the reduced scope of an exploratory IND clinical study.“
The expIND will accelerate discovery and development of new pharmaceutical agents* *PhRMA presentation January 2004
The expIND will accelerate discovery and development of new pharmaceutical agents* *PhRMA presentation January 2004
Bottom Line • CDER sees implementation of an exploratory IND guidance as an important part of FDA’s commitment to improving the “critical path” to new medical products. • The amount of preclinical safety data required for expINDs will generally be less than for conventional INDs. • Reduction in safety data requirements will be scaled to the goals, duration and scope of the proposed clinical trials.