1. Preclinical and Early Clinical Development of Microbicides XVII International AIDS Conference Mexico City, 2008

2. Topic Overview and Update Ian McGowan MD PhD FRCP Magee Womens Research Institute University of Pittsburgh, USA

3. Overview  Preclinical development  Microbicide pipeline  Preliminary evaluation  Regulatory  Safety  Efficacy  Early clinical development  Phase 1 vaginal safety studies  Phase 1 rectal safety studies  Challenges

4. Microbicides are products that can be applied to the vaginal or rectal mucosa with the intent of preventing or significantly reducing the risk of acquiring STIs including HIV

6. Mucosal Targets McGowan I, Biologicals, 2006

8. The Microbicide Pipeline

9. Microbicide Candidates UncertainDefense Enhancers Entry / Fusion Inhibitors  Ciclopiroxolamine  Praneem polyherbal  MucoCept HIV  Acidform™ gel  BufferGel™  Cellulose sulfate  Cellulose acetate  Carraguard  VivaGel  Dextrin-2 sulfate  Cyanovirin-N  C85FL  K5-N, OS(H)  SAMMA  Invisible condom  Novaflux  Porphyrins  PSC Rantes  BMS-806  BMS-378806  CMPD167  C52L  Tobacco-derived antibodies / fusion proteins  Anti-ICAM-1 Ab mAb B12, 2G12  mAb 2F5, 4E10  CD4 IgG2  T20  T-1249  SCH-C, D  UK-427,857  TAK 779  AMD3100  SFD-1  Bicyclams  Aptamers Membrane Disruption Replication Inhibitors  Alkyl sulfates  Savvy (C31G)  Beta cyclodextrin  Tenofovir  TMC-120  UC-781  MIV-150  MC1220  C-731, 988

10. Microbicides in Clinical Trials PhaseMembrane Disruption Defense Enhancers Entry Fusion Inhibitors Replication Inhibitors 1Ethanol in emollient LactobacillusDuet® CAP soft tablet VivaGel TM PC-815 UC-781 TMC-120 2 VivaGel TM 2/2BInvisible Condom TM BufferGel TM PRO-2000Tenofovir 3Acidform TM PRO-2000 Planned

11. The Million Dollar Question Preclinical Candidates Phase 1 / 2 Candidates Phase 2B / 3 Candidates $ $ $ ? ?

12. Preclinical Evaluation

13. Regulatory Studies  10-day vaginal irritation test in rabbits  PK studies to determine systemic absorption  Genetic toxicology studies  General toxicology studies  Safety pharmacology studies  Reproductive toxicology studies  Carcinogenetic studies  Hypersensitivity and photosensitivity studies  Condom integrity studies Lard-Whiteford SL et al. JAIDS 2004

14. Preclinical Safety

15. Safety Absence of evidence of harm + Absence of increased risk of HIV acquisition but Efficacy may be > safety

16. Preclinical Safety  Cell lines  Microbiology  Animal studies  Murine  Rabbit  Non-human primates  Explants  Cervicovaginal  Rectal

17. Cell Lines  Primary  Peripheral blood mononuclear cells  Mucosal mononuclear cell lines  Immortalized cell lines  HeLa  CaC02

18. Murine models  Nonoxynol-9 and HSV acquisition model  Phillips DM and Zacharopoulos VR. Contraception 1998 57(5):341-8.  Chlamydia acquisition model  Achilles SL et al. Sex Transm Dis 2002 29(11):655-64.

19. Non Human Primate

20. Rectal Lavage Assay Lavage fluid Day 4 Combo Animal Day 4, T0 24 hrs post 3rd application Day 4, T30 post 4th application 7X7X 15X30X *Microbicides 2008, New Delhi, Poster #TA-057

21. Explant Model Safety Assessment

22. Colorectal Intestinal Explants Endoscopic biopsies + Absorbable gelatin sponge Abner SR et al. JID 2005, Watts P et al. AIDS 2006

23. Colorectal Explant System Day 0 Day 1 Day 7

24. Product Safety Control TFV 1% Placebo TFVActive DrugPlacebo Osmolarity3347mOsm/kg3189 mOsm/kg pH4.454.39 SPL7013Active DrugPlacebo Osmolarity683 mOsm/kg803 mOsm/kg pH5.254.86 Control SPL7013 Placebo Iso-osmolar is 290 mOsm/kg Dezzutti et al. MTN Core Laboratory

25. 0 20 40 60 80 100 CAP Methyl Cellulose N9 KY PRO 2000 4% PRO 2000 0.5% PRO 2000p SPL7013 SPL7013p UC781 1% UC781 0.1% UC781p Vena Gel % Viability Toxicity of Topical Microbicides in Colorectal Explants Dezzutti C et al., AAC 2004

26. Preclinical Efficacy

27.  Cell lines  Animal studies  Murine  Non-human primates  Explants  Cervico-vaginal  Rectal

28. Murine Models  Di Fabio S et al. Vaginal transmission of HIV-1 in hu-SCID mice: a new model for the evaluation of vaginal microbicides. AIDS 2001 Nov 23;15(17):2231-8.  Khanna KV et al. Vaginal transmission of cell-associated HIV-1 in the mouse is blocked by a topical, membrane-modifying agent. J Clin Invest 2002 Jan;109(2):205-11.  Sun Z et al. Intrarectal transmission, systemic infection, and CD4+ T cell depletion in humanized mice infected with HIV-1. J Exp Med 2007 Apr 16;204(4):705-14.  Denton, P. W et al. 2008. Antiretroviral pre-exposure prophylaxis prevents vaginal Transmission of HIV-1 in humanized mice. PLoS Med 5:e16.

29. Non Human Primate Model

30.  Vaginal  PRO2000/5  Cellulose sulfate gel  Tenofovir gel  PSC Rantes  VivaGel™  CMPD 167  B12 antibody  BMS-378806  C52L  Rectal  Cyanovirin  Tenofovir

31. Macaque SIV Infection Anim al Week 0 Week 1 Week 2 Week 6 Week 12 Week 16 Week 20 VFPVFPVFPVFPVFPVFPVFP D77 ---++++++++++++++++++ D83 ---++++++++++++++++++ E73 ---++++++++++++++++++ E81 ---++++++++++++++++++ V = Virus isolation; F = Immunofluorescence P = PCR for proviral DNA Cranage M et al. PLOS Medicine, 2008

32. Rectal Tenofovir Week 0 Week 1 Week 2 Week 6 Week 12 Week 16 Week 20 VFPVFPVFPVFPVFPVFPVFP D3 ------+++++++++++++++ D30 --------------------- D37 --------------------- D39 --------------------- D43 ------++-+++--+--+--+ D79 --------------------- *Tenofovir given rectally 15 minutes before viral challenge V = Virus isolation; F = Immunofluorescence, P = PCR for proviral DNA

33. Rectal Macaque Tenofovir Data Proviral DNA Viral RNA

34. Explant Model Efficacy Assessment

35. Explant Model  Cervicovaginal  Penile  Intestinal  Anal  Rectal  Small intestine  Phase 1 assessment of efficacy

36. Viral Kinetics in Explants

37. Colorectal Explant Model

38. Microbicide Trials Network Algorithm Products Formulation Testing Osmolarity, pH, viscosity, in vitro release In vitro Testing Dose Range Cell lines Lactobacillus HIV efficacy Ex vivo Testing Cervical/colorectal tissue Absorption, permeability, and safety HIV efficacy Human Studies

39. Early Clinical Development

40. Clinical Evaluation  Phase 1  Sexually abstinent (1-2 weeks; N = 40-60)  Sexually active (1-2 weeks; N = 40-60)  Male tolerance study  Phase 2  Expanded safety (6 months; N = 200)  Phase 2B  HIV endpoint study (12-18 months; N = 4,000)  Phase 3  HIV endpoint study (12-18 months; N = 9,000) Mauck C et al. AIDS 2001

41. Phase 1 Vaginal Safety Studies

42. Key Endpoints  Signs and symptoms  Colposcopy  Microflora  Immune biomarkers  Cytokines  Antimicrobial peptides  (Histology)

43. Phase 1 Rectal Safety Studies

44. Rectosigmoid Anatomy

45. N-9 Effect on Rectal Epithelium Phillips et al. Contraception 2004 Baseline + 15 minutes + 2 hours + 8 hours

46. Phase 1 Rectal Safety Studies

47. UC-781 Trial Design Screening EnrollmentRandomization 0.1% 0.25% Placebo Baseline Endoscopy Single dose 2 nd Endoscopy 7 single Doses 3 rd Endoscopy

48. UC-781 Phase 1 Rectal Safety Study  Secondary Objective:  To determine whether use of study product is associated with rectal mucosal damage  Endpoints:  Epithelial sloughing  Histopathology  Mucosal mononuclear cell phenotype  Mucosal cytokine mRNA  Mucosal immunoglobulins  Fecal calprotectin  Explants- Mucosal cytokine mRNA and susceptibility to HIV infection

49. Phase 1RM Safety Studies ProductStatusTimelineSponsor UC-781CompletedNIAID/DAIDS PRO-2000PlannedQ4 2008MDP MRC-UK PolyanionPlannedQ1 2009NIAID/DMID MTN-007PlannedQ1 2009NIAID/DAIDS Tenofovir (PK)PlannedQ1 2009NIAID/DAIDS UC-781 (RF)PossibleQ4 2010TBD

50. IRMA Report www.rectalmicrobicides.org

51. Challenges

52. PERSPECTIVE Whither or Wither Microbicides? Robert M. Grant, 1 Dean Hamer, 2 Thomas Hope, 3 Rowena Johnston, 4 Joep Lange, 5 Michael M. Lederman, 6 Judy Lieberman, 7 Christopher J Miller, 8 John P. Moore, 9, Donald E. Mosier, 10 Douglas D. Richman, 11 Robert T. Schooley, 12 Marty S. Springer, 13, Ronald S. Veazey, 14 Mark A. Wainberg 15 Science, 2008 Vol 321;532-534

53. Drug Development Adapted from: Pharmaceutical Research and Manufacturers of America, 2006 Phase IPhase IIIPhase II Stage 1 Drug discovery Stage 2 Pre-clinical Stage 3 Clinical trials Stage 4 Regulatory review 7 years 6.5 years1.5 years 5 compounds 250 compounds 1 approved drug 10,000 compounds First clinical trial application submitted Marketing application submitted Rosenberg Z, 2007

54. Conclusions  Preclinical evaluation of microbicide candidates plays a critical role in the selection of products that should move into human studies  Components of preclinical evaluation and Phase 1 study design are in evolution  Rectal Phase 1 studies may provide safety and efficacy data  Need better assays to detect “immunotoxicity” but  Efficacy (RT microbicides) may be > than safety

55. Acknowledgements David Geffen School of Medicine Peter Anton MD St Georges Hospital Medical School Robin Schattock PhD Martin Cranage PhD International Partnership for Microbicides Zeda Rosenberg PhD NIH/NIAID/DAIDS & DMID U19 AI060614 NIH/NIAID/DMID U01 AI066734