1. September 10, 2007 MICROBIOTIX A product-focused, small molecule, anti-infective drug discovery company CONFIDENTIAL

2. September 10, 2007 The development of novel broad- spectrum anti-bacterials for intracellular BW threats

3. September 10, 2007 AGENDA Terry Bowlin, Ph.D. – Introduction/Welcome John Williams, Ph.D. – Chemistry Michelle Butler, Ph.D. – Microbiology/Cytotoxicity Donald Moir, Ph.D. – Mechanism Terry Bowlin, Ph.D. – Animal Studies Jennifer Brooks – Development Plan Terry Bowlin, Ph.D. – Goals/Milestones

4. September 10, 2007 AIMS Aim 1. Demonstrate potent, selective inhibitory activity of one or more bis- (imidazolinylindole) compounds in animal models of infection (year 1). Milestone: Identify an inhibitor exhibiting in vivo efficacy (ED 50 2 category A or B pathogens and minimum toxicity (MTD>300 mg/kg). Aim 2. Establish the mechanism of action of the bis-(imidazolinylindole) class of compounds (year 1). Milestone: Defined mechanism of action and target which are common to multiple bacterial BW species but distinctly different in mammalian cells Aim 3. Demonstrate structure-activity relationships for the potency and selectivity of the bis-(imidazolinylindole) class of compounds (year 2). Milestone: Identify key structural features for potency and selectivity; provide back-up compounds with MIC in serum 100. Aim 4. Conduct IND-enabling pharmacokinetic, toxicology and safety pharmacology studies (year 2). Milestone: Complete two species GLP toxicology & safety pharmacology studies for the optimal bis-(imidazolinylindole) compound suitable for IND submission. Aim 5. Prepare and file an IND application for a broad spectrum anti-bacterial active against intracellular BW threats (end of year 2). Milestone: IND approval for clinical Phase I human safety evaluation.

5. September 10, 2007 CHEMISTRY John Williams, Ph.D.

6. September 10, 2007 Synthesis of MBX 1066 5 Steps overall

7. September 10, 2007 Synthesis of MBX 1090 7 Steps overall

8. September 10, 2007 Synthesis of MBX 1113

9. September 10, 2007 Synthesis of MBX 1113 8 Steps overall

10. September 10, 2007 Synthesis of MBX 1128

11. September 10, 2007 Synthesis of MBX 1128

12. September 10, 2007 Synthesis of MBX 1128 13 Steps overall

13. September 10, 2007 Analogs of MBX 1066

14. September 10, 2007 MICROBIOLOGY/CYTOTOXICITY Michelle Butler, Ph.D.

15. September 10, 2007 Aim 1/2 Microbiology Studies Microbiology -- Original 4 compounds plus MBX 1066 analogs  MICs against standard Gram-pos. and Gram-neg. lab strains  MICs against category A or B bioterrorism pathogens  Cytotoxicity (CC 50 ) of compound

16. September 10, 2007 Average MIC (µg/mL) Bacterial Strain MBX 1066 (NSC-317881) MBX 1090 (NSC-317880) MBX 1113 (NSC-330687) MBX 1128 (NSC-369718) Bacillus subtilis BD540.1170.156 0.068 B. cereus ATCC 43420.0780.156 0.521 B. thuringiensis ATCC 107920.0780.3130.2350.182 B. anthracis Sterne0.2350.3130.1561.25 B. anthracis Ames  ANR (pXO1-, pXO2-) 0.0980.313 36.3 B. megaterium ATCC 128720.0780.1560.0780.176 B. licheniformis ATCC 145800.0590.3130.1560.117 Staphylococcus aureus ATCC 259230.1170.6250.3130.283 S. aureus (Smith) ATCC 137090.0780.3130.1560.078 Meth-res S. aureus (MRSA) 1094, clinical0.1370.6250.3130.508 S. aureus MT23142 NorA++0.0390.3130.2350.088 Enterococcus faecalis ATCC 292120.1370.313 0.107 Vanc-res E. faecalis (VRE) ATCC 515750.1170.6250.4690.107 E. faecium ATCC 194340.0590.1560.2740.088 VRE faecium B42762, clinical0.0390.3130.1560.068 MBX BLS1/2 MIC Data

17. September 10, 2007 Average MIC (µg/mL) Bacterial Strain MBX 1066 (NSC-317881) MBX 1090 (NSC-317880) MBX 1113 (NSC-330687) MBX 1128 (NSC-369718) Escherichia coli J53, lab strain0.3910.6250.31353.3 E. coli XL1Blue, lab strain0.0780.156 1.8 E. coli 700 TolC+1.250.6250.31380 E. coli 701 TolC-0.156 21.3 Klebsiella pneumoniae 5657, clinical0.2350.5800.35216.3 Pseudomonas aeruginosa PAO17.525 >80 P. aeruginosa PAO1 ΔmexAB-oprM1.15>20ND P. aeruginosa 278532.512.51.09>80 Burkholderia thailandensis E2646.25>8035>80 Stenotrophomonas maltophilia ATCC 136370.1760.6250.31311.3 Estimated Maximum Solubility in PBS (µg/mL) MBX 1066MBX 1090MBX 1113MBX 1128 40-8080-16020-40 MBX BLS1/2 MIC Data (continued)

18. September 10, 2007 Average MIC (  g/mL) Bacterial StrainTest SiteMBX 1066MBX 1090MBX 1113MBX 1128 P. aeruginosa PAO1 (control)Calgary85.3>8>8* S. aureus (Smith) ATCC 13709 (control) Calgary1.12520.75>8* Burkholderia pseudomallei 1026bCalgary0.653.2>8>8* Burkholderia mallei GB3Calgary120.67>8* Bacillus anthracis AmesUSAMRIID0.0670.0990.110.145 Burkholderia mallei ATCC 23344USAMRIID0.421.61.8>9.7 Burkholderia pseudomallei DD503USAMRIID1.73.11.8>9.7 Francisella tularensis Schu4USAMRIIDND1.560.924.9 Yersinia pestis CO92USAMRIID3.4>12.5>7.4>9.7 U. Calgary and USAMRIID BSL3 Data for MBX Compounds *Value determined only once.

19. September 10, 2007 Average MIC (µg/mL) Bacterial Strain MBX 1066 (NSC-317,881) MBX 1142MBX 1143MBX 1162 Bacillus subtilis BD540.1170.0680.0340.063 B. cereus ATCC 43420.0780.1070.0390.054 B. thuringiensis ATCC 107920.0780.1560.0780.117 B. anthracis Sterne0.2350.2150.0780.088 B. anthracis Ames  ANR (pXO1-, pXO2-) 0.0980.1560.0390.063 B. megaterium ATCC 128720.0780.0980.0340.037 B. licheniformis ATCC 145800.0590.1560.0490.088 Staphylococcus aureus ATCC 259230.1170.2740.1170.156 S. aureus (Smith) ATCC 137090.0780.2150.0780.102 Methicillin-res. S. aureus (MRSA) 1094, clinical0.1370.2930.1560.127 S. aureus MT23142 NorA ++0.0390.1780.0780.166 Enterococcus faecalis ATCC 292120.1370.1760.0780.156 Vanc-resistant E. faecalis (VRE) ATCC 515750.1170.1820.1560.137 E. faecium ATCC 194340.0590.2350.1370.186 VRE faecium B42762, clinical0.0390.2350.1560.137 BLS1/2 MIC Data for MBX 1066 Analogs

20. September 10, 2007 Average MIC (µg/mL) Bacterial Strain MBX 1066 (NSC-317881) MBX 1142MBX 1143MBX 1162 Escherichia coli J53, lab strain0.3910.430.1950.274 E. coli XL1Blue, lab strain0.0780.2150.0980.254 E. coli 701 TolC-0.1560.2540.1560.137 Klebsiella pneumoniae 5657, clinical0.2350.2540.1370.146 Pseudomonas aeruginosa PAO17.50.9380.2350.293 P. aeruginosa PAO1 ΔmexAB-oprM1.150.3130.1560.254 P. aeruginosa 278532.50.7810.2150.254 Burkholderia thailandensis E2646.2522.50.352 Stenotrophomonas maltophilia ATCC 13637 0.1760.1560.0780.156 Estimated Maximum Solubility in PBS (µg/mL) MBX 1066MBX 1142MBX 1143MBX 1162 40-80≥160ND40-80 BLS1/2 MIC Data for MBX 1066 Analogs (continued)

21. September 10, 2007 Average MIC (  g/mL) Bacterial StrainTest SiteMBX 1066MBX 1142MBX 1143MBX 1162 P. aeruginosa PAO1 (control)Calgary8412 S. aureus (Smith) ATCC 13709 (control) Calgary1.12540.50.75 Burkholderia pseudomallei 1026bCalgary0.65110.375 Burkholderia mallei GB3Calgary1ND Burkholderia mallei ATCC 23344USAMRIID0.421.8 0.6 Burkholderia pseudomallei DD503USAMRIID1.71.80.6ND Francisella tularensis Schu4USAMRIIDND1.8ND1.8 Yersinia pestis CO92USAMRIID3.43.5ND3.5 U. Calgary and USAMRIID BSL3 Data for MBX 1066 Analogs

22. September 10, 2007 CC 50 of MBX 1066 and its analogs on HeLa cells Compounds CC 50 (µg/mL) MIC S. aureus 25923 (µg/mL) Selectivity Index (in vitro) MBX 1066 >200.117>170 MBX 1090 100.62516 MBX 1113 30.3139.6 MBX 1128 170.28360 MBX 1142 140.27451 MBX 1143 130.117111 MBX 1162 40.15626 HB-EMAU 3557

23. September 10, 2007 MICROBIOLOGY SUMMARY Accomplishments: All four of the original lead compounds have been remade and retested in an independent laboratory with similar antibacterial potencies, especially with relevant BSL3 strains MBX 1066 displays the most favorable in vitro selectivity index with low mammalian cell cytotoxicity 14 analogs of MBX 1066 have been tested to date and several maintain activity against the Gram-positive strains while displaying greater potency against Gram-negative strains Future work: We will continue to acquire and test other relevant bacterial strains against the current compounds and new series as they are synthesized

24. September 10, 2007 MECHANISM Donald Moir, Ph.D.

25. September 10, 2007 AIM 2 Establish the mechanism of action of the bis- (imidazolinylindole) class of compounds (year 1). Milestone: Defined mechanism of action and target which are common to multiple bacterial BW species but distinctly different in mammalian cells

26. September 10, 2007 Antibacterial Mechanism of bis-(imidazolinylindole) compounds Favorable in vitro therapeutic index (CC 50 /MIC) indicates selectivity for bacteria Rapid bactericidality implicates DNA, RNA, cell wall or membrane targets DNA synthesis is the most sensitive of the macromolecular pathways to MBX 1066 (effects observed at >10x MIC) The bis-(imidazolinylindole) compounds interact with DNA Fluorescence enhancement in the presence of DNA (Max 1/2 ~0.4 μM) Inhibition of Replix TM (IC 50 ~2 μM) & replicative helicase (IC 50 ~1 μM) ~2x preference for AT-rich B. anthracis DNA vs. calf thymus DNA Target appears to be cytoplasmic Fluorescence enhancement of compound observed within bacterial cells MIC is significantly lower in efflux mutant of P. aeruginosa Very low frequency of mutation to resistance Minimal effects on cell membranes No lysis of membranes No perturbation of the membrane potential near the MIC for some compounds Working Hypothesis: The bis-(imidazolinylindole) compounds enter bacterial cells, bind preferentially to AT-rich DNA, and inhibit one or more DNA replication functions

27. September 10, 2007 Rapid Bactericidal Activity of MBX 1066, 1090, 1142 and 1162 Compound MBX 1066MBX 1090MBX 1142MBX 1162 Time to reach cidal effect (hours) 241.51

28. September 10, 2007 Macromolecular Synthesis Assays in S. aureus — MBX 1066 DNA synthesis is the most sensitive macromolecular pathway to MBX 1066 treatment – effects are observed at >10 μg/ml

29. September 10, 2007 Conclusion: Half-maximal DNA interaction by MBX 1066 occurs at about 0.4 μM (~0.3 μg/ml) Fluorescence Enhancement of MBX 1066 in the Presence of DNA – Concentration Dependence

30. September 10, 2007 MBX 1066, 1090 and 1113 are Potent Inhibitors of Replix™, a Permeable Cell DNA Replication Assay IC 50 µM (µg/mL) Against Permeable Bacteria CompoundB. subtilisB. anthracis MBX 1066 2.2 (1.5)4.1 (2.8) MBX 1090 4.8 (3.0)7.7 (4.8) MBX 1113 2.6 (0.95)6.1 (2.2) HB-EMAU (pos. ctl.) 1.1 (0.35)2.0 (0.63)

31. September 10, 2007 Conclusion: MBX 1066 & 1090 are very potent B. anthracis helicase inhibitors with IC 50 ’s of <1 μM (<0.6 μg/ml) Helicase Inhibition by MBX 1066 & 1090 as Measured by 32 P-Based Unwinding Assay – Comparison to Other Helicase Inhibitors

32. September 10, 2007 DNA Interaction with MBX 1066 & Hoechst 33258 in the Presence of Increasing Concentrations of Calf Thymus or B. anthracis Genomic DNA Conclusion: Affinity of both MBX 1066 and Hoechst 33258 for AT-rich B. anthracis DNA is ~2-fold stronger than for calf thymus DNA Average A+T content: 64% for B. anthracis DNA vs. 58% for calf thymus DNAc

33. September 10, 2007 In situ Fluorescence of MBX 1066 in S. aureus cells is Consistent with Cell Penetration & DNA Binding None1 X MBX 10664 X MBX 10661 X MBX 10904 X MBX 1090 4 X MBX 1113 DIC DAPI DIC DAPI Intracellular fluorescence readily detected at 1X MIC Consistent with DNA-dependent fluorescence enhancement 1 X MBX 1066 Contrast enhanced 10X zoom cytoplasmic localization

34. September 10, 2007 Average MIC (µg/mL) Bacterial Strain MBX 1066 (NSC-317881) MBX 1142MBX 1143MBX 1162 Pseudomonas aeruginosa PAO17.50.9380.2350.293 P. aeruginosa PAO1 ΔmexAB-oprM1.150.3130.1560.254 MBX MIC Data for MBX 1066 & Analogs Isogenic P. aeruginosa Strains +/- a Major Efflux Pump Conclusion: MIC of MBX 1066 is significantly improved by loss of major efflux pump; analogs may be better at escaping efflux

35. September 10, 2007 Mutation to Resistance to MBX 1066 is Rare in S. aureus NCTC-8325 Serial Passage A B C D E FGH Highest Sublethal Concentration (Fold MIC) S. aureus NCTC 8325 Resistant mutants-16X MIC

36. September 10, 2007 MBX 1090 Resistant Mutants are not Cross- Resistant to MBX 1066 MICs vs MBX 1090, MBX 1066, and MBX 1113 No cross resistance to MBX 1066, suggesting different MOAs for MBX 1090 and MBX 1066

37. September 10, 2007 Bacterial membrane perturbation assay using DiSC 3 (5) DiSC 3 (5) Ex-622 Em-670 e - transport QUENCH 2H+ Ex-622 Em-670 Membrane disrupter Membrane potential perturbation No membrane potential perturbation by compound Membrane potential perturbation by compound

38. September 10, 2007 Summary of Membrane effects of bis- (imidazolinylindole) Compounds in DiSC 3 (5) assay Conclusion: MBX 1066 & 1128 do not perturb membrane potential at concentrations near the MIC

39. September 10, 2007 DiSC 3 (5) Membrane Perturbation Assay of MBX 1066 & Analog MBX 1162 Results of DiSC 3 (5) assay 10 min after compound addition Conclusion: MBX 1066 & 1162 do not perturb membrane potential at concentrations near the MIC

40. September 10, 2007 MBX 1066 & 1090 do not disrupt HeLa cell membranes Monolayers of HeLa cells were exposed to MBX 1066 and a control antibiotic (vancomycin) for 1 h. Activity of the cytoplasmic enzyme lactate dehydrogenase (LDH) released into the media was measured after 30 min. Similar results obtained with MBX 1090 and MBX 1113

41. September 10, 2007 Favorable Features of MBX 1066 Antibacterial Mechanism In vitro therapeutic index (CC 50 /MIC >170) is favorable for MBX 1066 MBX 1066 is rapidly bactericidal DNA synthesis is the most sensitive macromolecular pathway to MBX 1066 (effects observed at >10x MIC) Interacts with DNA MBX 1066 fluorescence increase in the presence of DNA (Max 1/2 ~0.4 μM) Inhibits Replix TM (IC 50 ~2 μM) & replicative helicase (IC 50 ~1 μM) ~2x preference for AT-rich B. anthracis DNA vs. calf thymus DNA Target appears to be intracellular Fluorescence enhancement observed within bacterial cells MIC is significantly lower in efflux mutant of P. aeruginosa Very low frequency of mutation to resistance Minimal effects on cell membranes MBX 1066 does not lyse membranes or perturb the membrane potential at <4x MIC Conclusion: MBX 1066 is less cytotoxic, exhibits fewer membrane effects, and is less susceptible to mutation to resistance than are MBX 1090, 1113, or 1128

42. September 10, 2007 Future Mechanism Studies Perform genetic expression profile analysis. Expression profiling in the presence of various concentrations of bis(imidazolinylindole) compounds to identify genes up- and down-regulated in response to compound treatment Perform target under-expression hypersensitivity and over- expression resistance assays. For implicated single gene targets, construct and test strains over- and under-expressing those putative targets to confirm MOA in the cell Map loci responsible for resistance. Select resistant strains and map resulting mutations to identify genes which can confer resistance

43. September 10, 2007 ANIMAL STUDIES Terry Bowlin, Ph.D.

44. September 10, 2007 In Vivo Testing of Lead Antimicrobial Compounds in B. anthracis Note: MBX 1066 protected 5/5 mice for 14 days in a previous Ames challenge experiment

45. September 10, 2007 In Vivo Testing Against F. Tularensis

46. September 10, 2007 In Vivo Testing in Y. Pestis Murine Model

47. September 10, 2007 Efficacy of MBX 1162 in a murine IP/IP B. pseudomallei infection model GroupnTreatmentDose, mg/kg # surviving at 48 hr % survival 15D/po-00 25Tetracycline105100 35MBX 1162105100 Three groups of 5 Balb/C mice (female, 20-22g) were inoculated intraperitoneally with 10 6 cells of Burkholderia pseudomallei strain 1026b. Mice were treated intraperitoneally ten minutes post infection with tetracycline (10 mg/kg), MBX 1162, or vehicle alone

48. September 10, 2007 Efficacies of MBX compounds in a murine IP/IP S. aureus infection model survivors GroupntreatmentDose, mg/kg8 hr18 hr24 hr48 hr % surviv al 110D/po-711110 2 Dapto10999990 310MBX 1066110 100 410MBX 106610 100 510MBX 1090110 100 610MBX 109010 100 76D/po-511116.7 86Dapto106666100 910MBX 1113110 100 10 MBX 111310 100 1110MBX 1128110 100 1210MBX 112810 100

49. September 10, 2007 survivors GroupntreatmentDose, mg/kg8 hr18 hr24 hr48 hr % survival 110 DMA/D5W, pH 3.52 -222220 210Dapto10 100 310MBX 106610988880 410MBX 109010 99990 52MBX 1113102 mice died immediately after injection 5’8MBX 11131211112.5 61MBX 1128101 mouse died immediately after injection 6'9MBX 1128152000 Efficacies of MBX compounds in a murine IP/IV S. aureus infection model

50. September 10, 2007 NCI IDDose (mg/kg/ injection) Sched.Route#Mice#Surviving on Day 5 NSC 317880100Q04DX003i.p.66 (MBX 1090)200Q04DX003i.p.66 400Q04DX003i.p.66 NSC 317881100Q04DX003i.p.66 (MBX 1066)200Q04DX003i.p.66 400Q04DX003i.p.66 NSC 33068725Q04DX003i.p.66 (MBX 1113)50Q04DX003i.p.66 100Q04DX003i.p.65 200Q04DX003i.p.65 400Q04DX003i.p.62 NSC 36971850Q01DX005i.p.66 (MBX 1128)100Q01DX005i.p.66 200Q01DX005i.p.66 Toxicity Determination in Mice

51. September 10, 2007 MBX 1066 Product Development Jennifer Brooks Regulatory Affairs Manager Microbiotix, Inc.

52. September 10, 2007 MBX 1066 Development Goal Develop a new chemical class of therapeutic agents for use against intracellular bacterial biowarfare threats. Indication Treatment of exposure to Bacillus anthracis: inhalational anthrax (post-exposure); to reduce the incidence or progression of disease following exposure to aerosolized B. anthracis. RouteIntramuscular Dosing RegimenTBD based on additional pharmacokinetic data

53. September 10, 2007 Preclinical Development Plan XIn vitro pharmacology PK – rodent (IV/IM) PK – primate (IV/IM) Toxicology – rodent (IV) Toxicology – primate (IVIM) Efficacy – primate (IM) – concurrent with Phase 1 Genetic toxicology Plasma protein binding Plasma compatibility Safety pharmacology

54. September 10, 2007 Efficacy Study Design Rhesus monkeys N = 10 per group Control group Active control group 30 day study 70 day observation PK samples Endpoints will include: survival, bacteremia, microbial burden, histopathology

55. September 10, 2007 Clinical Studies Phase 1 Concurrent with primate efficacy study Safety Pharmacokinetics Phase 2/3 depending on feedback from FDA Alternate indications Approval/Marketing Advisory committee likely ?Restricted distribution (eg, military only)

56. September 10, 2007 CMC Development Plan Chemical characterization Solubility Hygroscopicity Xray crystallography Etc. Formulation development Source materials/excipients Analytical method development and testing In-process Release (water, impurities, residual solvents, etc.) Stability testing Routine (including accelerated) Other (photostability, etc.) Identify and qualify manufacturers Develop preliminary specifications

57. September 10, 2007 Regulatory Next steps Pre-IND meeting early 2008  Preliminary toxicology data  PK data Conduct remaining IND-enabling studies IND August 2008 Anticipate approval under Subpart H Accelerated approval Surrogate endpoint – efficacy in primates; PK and microbiology data

58. September 10, 2007 MBX 1066 SUMMARY Very potent broad spectrum agent that is active against Gram-positive and Gram-negative bacteria Rapidly bactericidal MOA consistent with DNA binding/helicase inhibition No resistance observed so far Effective in murine models against Gram-positive and Gram-negative bacteria, with ED 50 <10mg/kg Well tolerated, with murine MTD >400mg/kg Easy and inexpensive to synthesize Next step: IND enabling GLP toxicology

59. September 10, 2007 TIMELINE Year 1Year 2 Task1Q2Q3Q4Q1Q2Q3Q4Q 4.1 Efficacy 4.1.1 Small Scale Synthesis 4.1.2 Large Scale Process 4.1.3 In vitro potency 4.1.4 In vivo potency 4.1.4.1 F. tularensis 4.1.4.2 Y. pestis 4.1.4.3 C. burnetii 4.1.4.4 B. pseudomallei 4.1.4.5 B. mallei 4.1.5 Murine toxicity Milestone: Identify a Lead Compound  4.2 Mechanism of Action 4.2.1 Macromolecular Synthesis 4.2.2 Membrane Perturbation 4.2.3 Map Loci 4.2.4 Genetic Expression Profile 4.2.5 Hypersensitivity and Resistance Milestone: Defined MOA 

60. September 10, 2007 TIMELINE (continued) Year 1Year 2 Task1Q2Q3Q4Q1Q2Q3Q4Q 4.3 SAR 4.3.1 Molecular Modeling 4.3.2 Synthesis of Analogs 4.3.2.1 NSC 317,880 4.3.2.2 NSC 317,881 4.3.2.3 NSC 330,687 4.3.3 Biological Evaluation 4.3.3.1 Potency 4.3.3.2 Cytotoxicity 4.3.3.3 Kinetics 4.3.3.4 Frequency of Resistance 4.3.3.5 Bioavailability (in vitro) 4.3.3.6 Drug Interactions 4.3.3.7 Metabolic Stability 4.3.3.8 QT Interval Milestone: Backup Compounds Identified 

61. September 10, 2007 TIMELINE (continued) Year 1Year 2 Task1Q2Q3Q4Q1Q2Q3Q4Q 4.4 IND-Enabling Studies 4.4.1 Compound Scaleup 4.4.2 PK and Bioavailablity 4.4.3 Toxicology Studies 4.4.3.1 Rat 4.4.3.2 Primate 4.4.3.3 Genetic 4.4.4 Safety Pharmacology Milestone: 2 spec. Tox & Safety Profile  4.5 Prepare and File IND 4.5.1 Hire Regulatory Manager 4.5.2 Project Reports 4.5.3 Clinical Protocols 4.5.4 FDA Pre-meeting 4.5.5 Compile IND Milestone: IND Filing 