FDA s Clinical Investigator Course

1. Cosponsored by FDA�s Office of Critical Path Programs (OCPP) and The Clinical Trials Transformation Initiative (CTTI) FDA�s Clinical Investigator Course

2. Phase 1 case Study Owen McMaster, Ph.D. Pharmacology/Toxicology Reviewer Division of Special Pathogen and Transplant Products Office of Antimicrobial Products Office of New Drugs Center for Drug Evaluation and Research Food and Drug Administration

3. Guiding Principles All things are poison and nothing is without poison; only the dose makes a thing not a poison. Theophrastus Phillipus Auroleus Bombastus von Hohenheim (1493�1541) aka Paracelsus All models are wrong, but some are useful George Box

4. Outline-Harnessing benefits safely The MYCAXIS story Pre-IND IND Clinical hold Complete response to clinical hold

5. The NOAEL The highest dose level that does not produce a significant increase in adverse effects� adverse effects that are statistically significant and adverse effects that may be clinically significant (even if they are not statistically significant) should be considered. Note: some effects observed in the animal may be acceptable pharmacodynamic actions of the therapeutic and may not raise a safety concern. The no-observed-adverse-effect-level in drug safetyevaluations: Use, issues, and definition(s) M.A. Dorato, J.A. Engelhardt / Regulatory Toxicology and Pharmacology 42 (2005) 265�274

6. The Pre-IND Consultation Program-21 CFR 312.82 Purpose To facilitate and foster early consultation. Agree on the design of animal studies (nonclinical pharmacology, toxicology, drug activity studies, proposed treatment studies in animal models) needed to initiate human testing. Discuss the scope and design of Phase I testing Discuss the regulatory requirements for demonstrating safety and efficacy Pediatric studies Presentation and formatting of data in the IND For life-threatening and severely-debilitating illnesses

7. MYCAXIS Sponsor submitted a pre-IND Anti bacterial for life threatening indication To be used for 3-6 months or more. Primary Pharmacology Safety Pharmacology Pharmacokinetics Genetic Toxicology Draft Repeat-dose Toxicology in rats and dogs. Dogs pretreated with metoclopramide to prevent vomiting.

8. MYCAXIS Sponsor advised to submit Complete reports NOAEL�s

9. MYCAXIS 14-day dose range finding in male rats. 14-day dose oral/iv range finding in dogs. 4-week dose oral/iv range finding study in dogs. 14-day intravenous study in dogs. 90 day study in dogs with 30-day recovery period (LM+EM) 90 day study in rats with 30 day recovery period (LM+EM)

10. NOAEL�s and HED�s

11. MYCAXIS Three month study in dogs, 5, 15 or 50 mg/kg MYCAXIS, Mild to moderate neuron microvesicular vacuolation/ degeneration was observed in the forebrain, midbrain and hindbrain of all animals at the high dose. No drug-related lesions were observed at 5 mg/kg/day with light microscopy evaluation. There was no evidence of recovery 30 days after discontinuing drug administration.

12. MYCAXIS -degeneration, neuron

13. MYCAXIS -Electron Microscopy �Degeneration� consisted of lamellated ultrastructural inclusions (myelinosomes) in the neuronal perikarya. This lesion was present in all treated groups The number of myelinosomes and the severity of the changes appeared to be dose-dependent. In the 50 mg/kg/day group, the perikarya of neurons had numerous, tightly packed myelinosomes which usually displaced the nucleus peripherally in the perikaryon. Structurally, these myelinosomes appeared to have a minimal granular core.

14. MYCAXIS -Recovery after 90-day treatment period, No evidence of myelinosomes in the low-dose animals. One of 3 animals in the mid-dose group had early stage myelinosomes comparable to the terminally sacrificed animals High-dose recovery group, only available animal had advanced myelinosomes.

15. MYCAXIS-myelinosomes (Magnification x3000)

16. MYCAXIS-early myelinosomes (Magnification x30,000)

17. MYCAXIS- advanced myelinosomes

18. NOAEL�s and HED�s

19. Proposed Phase 1a clinical study Single dose 8 Healthy adults/group 5,10, 20, 50 or 100 mg doses Subjects will be monitored for 7 days after which a decision will be made to test the next higher dose. A sixth group will be dosed at the dose below the maximum tolerated dose after a high fat meal to determine the effect of food on the pharmacokinetics of MYCAXIS. The initial dose of 5 mg is equivalent to 0.08 mg/kg for a 60 kg patient based on body surface area. Allowed to proceed with this single dose study.

20. Issue # 1 �Neurodegeneration� H & E staining Hematoxylin (H), is a basic dye which colors basophilic structures (ribosomes and the chromatin-rich nucleus and cytoplasmic regions rich in RNA) with blue-purple hue, Alcohol-based acidic eosin Y (E), which colors eosinophilic structures (generally protein, such as most of the cytoplasm) bright pink. Loss of RNA staining is taken as evidence that neuron function has been compromised

21. What is neurodegeneration? Neurodegeneration �loss of structure or function of neurons including cell death �Degeneration, neuron� was diagnosed when neuron cytoplasm contained small clear vacuoles or grainy cytoplasm which frequently compressed the remaining cytoplasm around the nucleus. In some neurons, the nucleus was displaced from the normal central location to the plasma membrane. In some cases, the size of the neurons appeared increased. -Pathologist Neurodegeneration was not necessarily the cause of this observation Concentric whorls observed using electron microscopy bore the classic features of phospholipidosis. Contacted the sponsor and requested re-evaluation of slides.

22. Selective neuronal degeneration detection Fluoro-Jade B is an immunofluorescent dye that binds preferentially to damaged neurons Silver degenerative stain such as cupric silver highlights affected neurons Anti-glial fibrillary acidic protein (GFAP) immunohistochemistry �GFAP expression is one of the most persistent markers of cell necrosis. Marker for astrocyte response to neurotoxicity Recommended staining to determine if this phospholipidosis was associated with cell damage.

23. Issue # 2: A Rat is not a dog Rats showed no neurodegeneration or myelinosomes via light microscopy or electron microscopy Dogs showed effects via light and electron microscopy Difference in metabolism? Requested that sponsor study metabolism in both species to investigate if differences in metabolism could explain the difference in susceptibility

24. Issue # 3 Light vs. electron microscopy Shorter studies had no �neurodegeneration� as viewed by the light microscopy but did they have myelinosomes? We requested that the sponsor demonstrate a NOAEL using electron microscopy before repeat-dose studies could be conducted.

25. Issue #4 Phospholipidosis Typical features (1) excessive accumulation of phospholipids in cells (2) ultrastructural appearance of membranous lamellar inclusions, predominantly lysosomal in origin; (3) accumulation of the inducing drug in association with the increased phospholipids (4) reversibility of alterations after discontinuance of drug treatment. Recommended that sponsor consult with pathologist to further evaluate the lesion. Drug-Induced Phospholipidosis: Are There Functional Consequences? Mark J. Reasor and Sam Kacew Experimental Biology and Medicine 226:825-830 (2001)

26. Issue #5 Metoclopramide Sponsor argued that metoclopramide was causing/contributing to phospholipidosis Agency recommended study of intravenous dosing with or without metoclopramide with electron microscopic evaluation

27. Phase 1B clinical trial Cohort 1 � 75 mg or placebo once daily for 14 days Cohort 2 � 150 mg or placebo once daily for 14 days Cohort 3 � 150 mg or placebo once daily on day 1-5, 9, and 14 Followed for an additional 14 days following the last dose. Initiation of dosing in cohorts 2 and 3 will occur only after assessment of cohort 1 safety parameters. Dosing of subjects in cohorts 2 and 3 will be done in parallel.

28. 21CFR312.42- Clinical hold -an order issued by FDA to the sponsor to (a) delay a proposed clinical investigation or (b) to suspend an ongoing investigation.

29. Grounds for imposition of clinical hold 21CFR312.42 unreasonable and significant risk of illness or injury; clinical investigators named in the IND are not qualified investigator brochure is misleading, erroneous, or materially incomplete IND does not contain sufficient information required under 312.23 to assess the risks to subjects of the proposed studies. men or women with reproductive potential who have the disease or condition being studied are excluded from eligibility because of a risk or potential risk from use of the investigational drug of reproductive/developmental toxicity even though drug is for a life threatening condition.

30. Clinical Hold letter The following are the specific deficiencies (1) 21 CFR 312.42(b)(i). Human subjects are or would be exposed to an unreasonable and significant risk of illness or injury. (2) 21 CFR 312.42(b)(iv).The IND does not contain sufficient information required under �312.23 to assess the risks to subjects of the proposed studies.

31. Information needed to resolve clinical hold deficiencies (1) Conduct a GLP toxicology study of MYCAXIS in a non-rodent species (such as nonhuman primate) Include evaluation of any functional consequences at maximum feasible dose. (2) Include a post-dosing recovery period to evaluate reversibility of adverse findings. (3) Evaluate the metabolic profile of MYCAXIS in the animal model to ensure that there are no major differences between the metabolic profiles in the animals model and humans prior to the larger toxicology study. (4) Evaluate all major brain regions and consult neuropathology experts before selecting the number of sections of brain tissues to examine and the types of stains to employ (6) Provide additional information about the light microscopic (LM) lesions designated �degeneration, neuron�. Please determine if there is any evidence of cellular reaction to injury, loss of structure or a degradative process including cell death.

32. Sponsor�s response Initiate nonhuman primate study Conducted 2 week study of oral MYCAXIS in dogs with reversibility arm and electron microscopy Conducted 2 week study of intravenous MYCAXIS in dogs with reversibility arm and electron microscopy Adjusted the proposed dosing downwards.

33. Sponsor�s response 14-day oral study in dogs (1.5 and 10 mg/kg/day) No brain lesions seen by light microscopy at end of treatment or end of reversibility No brain lesions seen by electron microscopy at end of treatment or end of reversibility 14-day intravenous study in dogs (5 mg/kg with or without metoclopramide) Early myelinosomes seen in 4/12 dogs by electron microscopy at end of treatment. Early myelinosomes seen in 8/8 dogs by electron microscopy at end of the reversibility period A recovery period of 14 days after treatment with MYCAXIS does not permit the lysosomes in pontine neurons to return to a normal ultrastructural state.

34. Agency Response Remove clinical hold because we have a well defined NOAEL for the proposed clinical regimen. Human subjects would NOT be exposed to an unreasonable and significant risk of illness or injury. The IND DOES contain sufficient information required under �312.23 to assess the risks to subjects of the proposed studies.

35. Lessons Communicate early for clear answers (Pre-IND) Act on our advice. Establish NOAEL It not always clear if a man is more like a rat or a dog or a monkey Working together, we can keep the drug development process moving as we get the answer.