Whats New in Drugs and Drug related Tools '

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Whats New in Drugs and Drug related Tools
.

• 1. Summary of new drugs in clinical trials
• Research tools
• 2. Treatment shortening with existing drugs
• Biomarkers
• using of radiotracers for M. tb.
• Biomarkers
• - use of exhaled breath to monitor Tx response

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Whats New in Drugs and Drug related Tools
.

• Drugs in Clinical Trials
• TMC207 diarylquinoline (Tibotec) promising Ph 2
  study in MDRTB Diacon et al
  ICAAC 2008
• OPC67683 nitroimidazole (Otsuka) Ph 2 study in
  MDRTB ongoing Geiter et al IUATLD
  2008
• PA824 nitroimidazole (TB Alliance) promising EBA
  study Ginsburg et al
  IUATLD 2008
• Meropenem/Clavulanate Unexpectedly high in vitro
  activity vs. TB, MDRTB
• Blanchard et al Science 2009 3231215

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2. Treatment shortening with existing drugs
Recapitulation of the short-course regimen in
the mouseas in humans?
Log10 cfu in lungs
months
Tubercle 1978 59287 1986675 Rosenthal et
al PLoS Med 2007 4 e344
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2. Treatment shortening with existing drugs the
potential of Rifapentine and Moxifloxacin
(5/7)
(5/7)
2 logs
(5/7)
4 logs
Rosenthal et al., AJRCCM 2006 175 A509
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• 3. Biomarkers -- developing radiotracers for M.
  tb.

. . . the (antiquated) CFU count . . .
Each organ homogenized ? 2-4 plates
Each plate incubated ? 4-6 weeks
Each point 6 mice ?12 organs
4-6 wk. later, each plate counted averaged
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Small Animal Imaging JHU Animal BSL-3
A. NanoSPECT/CT capable of high-resolution CT
(40 µm) and multiplexed, multi-pinhole high
resolution (lt0.5 mm), high sensitivity (gt250-400
cps/MBq) SPECT imaging and B. Philips MOSAIC HP
PET with PIXELAR detector technology, large 18
cm imaging bore with clinical reliability. Both
scanners were recently installed in the Center
for TB Research vivarium in the CRB2 building,
one floor below our main labs and offices.
SPECT/CT (single photon emission 125I, 44mTc)
PET (positron emission 18F)
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18FFDG-PET Measuring inflammation
C3HeB/FeJ mice low dose aerosol infection
Week 6
Mean lung SUV were significantly higher for the
infected mice (3.24 0.27) compared to the
uninfected mice (1.19 0.19) at all time-points
measured (plt0.02)
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A
Normalized Mean PET Activity (SUV)
Relapse
Lung Bacterial Burden (log10 CFU)
B
Weeks after starting anti-TB therapy
Aerosol infection
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Correlating CFU and PET signal during drug
treatment

• BALB/c mice infected with M. tuberculosis H37Rv
  via the aerosol route
• 2 weeks after infection, mice received either a
  highly active anti-TB regimen (daily P10MZ) or a
  bacteriostatic regimen (ethambutol alone)
• 3 mice were used for each group and the same
  animals were serially imaged using
  18FFDG-PET/CT at 2, 4 and 8 weeks after
  starting anti-TB therapy
• Uninfected mice were used as controls. At each
  time, an additional 3 mice were sacrificed for
  lung CFU
• Mean PET activity is significantly lower for the
  highly active anti-TB regimen compared with the
  bacteriostatic regimen

E only (weak Rx)
PMZ (strong Rx)
E only (weak Rx)
PMZ (strong Rx)
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Can we image the microbe? Recombinant M. tb.
(thymidine kinase) 125I-thymidine analog tracer
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Visualization of M. tb. lesions in sst1
(susceptible) C3HeB/FeJ mice
AFB
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4. Surrogate Markers Rabbit TB Model the
smallest animal with cavitary TB

• Rabbits
• Susceptible
• Resistant
• Sensitization
• Microorganisms
• M. bovis
• M. tuberculosis
• Dose of infection
• Low versus High
• Routes of infection
• Intravenous
• Transthoracic
• Aerosol

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4. Biomarkers use of exhaled breath to monitor
Tx response, the urea breath test

• Urease Nickel-containing enzyme that catalyzes
  the decomposition of urea to carbon dioxide and
  ammonia
• Urease producing organisms
• 1. Proteus vulgaris/mirabilis
• 2. Klebsiella aerogenes
• 3. Helicobacter pylori
• 4. M.tb. complex

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The Rabbit Cavitary TB Model
FOR INFECTION
clinical appearance, weight and rectal
temperature monitored twice weekly
FOR MEASUREMENTS
Tubercle Count Gross pathology
Molecular Biology
Histopathology
CFUs
Imaging
Immunology
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4. Biomarkers the urea breath test to monitor
Tx response in rabbits

• Methodology
• Organisms Animals Non-sensitized rabbits as
  previously described (Approximately 4 log of
  M.bovis in 5 non-sensitized rabbits)
• Dosage 20-35mg of 13-C urea (100mg/mL
  concentration)
• Route Via a feeding tube inserted through a 4.0
  ETT
• Air extraction Baseline, 1 minute, 5 minute, 10
  minute and 20 minutes
• Time points Pre-infection, early infection and
  late infection
• Confounders (i.e. H. pylori) untested due to
  laboratory issues

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Urea Breath Test for TB ?
In vitro
13C CO2 in gaseous phase
M. bovis late cavity
In vivo (50-80 day cavitary rabbit)
uninfected
13C CO2 in gaseous phase
M. bovis early cavity
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In-vitro experiment
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Urease conversion in H37Rv and Bovis
? Treatment with INH 25 mg/kg x 2 weeks
J1 H37Rv
J2 - Bovis
J3 - Bovis
J6 - Bovis
J4 - Bovis
J5 - H37Rv
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Conversion rate of 13CO2 per minute
Post-infection
During Treatment
Baseline
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Unanswered questionspartial explanations

• Delivery of virulence effectors
• Virulence effectors Lipids, proteins, small
  molecules
• Immunopathologyan excessive TNFa response
• Surrogate markers

• RD1 gene locus

• Esat6, CFP-10, PknG, PGL, other lipids

• Bacterial adenylate cyclase intoxication

• Urea Breath Test

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Controlling TB major eras in time
Sanitation / Sanatoria Antibiotics
1902
Pre-1882
1944
2009
1998
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What will the next snapshot be ?
Sanitation / Sanatoria Antibiotics
The XDR era ?
1902
Pre-1882
1944
2009
1998

• In roughly 55 years, we have squandered our
  precious legacy of chemotherapy for these XDR-TB
  cases. Darwin, though, would understand.
• --M. Iseman, Dec. 2007