Penetration of rifampin and rifapentine

into diseased lung in the rabbit cavity

pulmonary disease model of TB

Dalin Rifat, Ph.D.

9-17-2015

D I V I S I O N O F

CLINICAL

PHARMACOLOGY

• Rifampin (RIF) and rifapentine (RPT) are potent sterilizing drugs

• In mouse models daily RPT can cure TB in 3 months

• In clinical trials, substitution of 10 mg/kg of daily RIF with 10 mg/kg of

daily RPT is not more efficacious; higher doses of RPT seem to

improve microbiologic outcomes

• There is little information about the penetration of rifamycins into

infected areas in humans

• The rabbit cavitary pulmonary TB model has human-like TB pathology

(necrotic granulomas and cavities) and may provide some insights

into drug distribution of anti-TB drugs in humans.

Background

Rabbit cavitary model

105 -106 CFU/ml of Mtb H37Rv

Cavitary

lesion

Aerosol infection

Bronchoscope infection

Injection of Mtb:H37Rv

1-0.3ml

105 -107 CFU/ml

Experimental design

Drug delivery:IV infusion

Plasma

70%methanol

Homogenate

LC/MS

MALDI-MSI

Uninvolved lung tissue (UI)

Tissue surrounding lesion (SL)

Cellular lesion (LE)

Cavitary lesion wall (CAW)

caseum (CAC)

RIF: 5mg/ml

RPT: 10mg/ml

In vehicle solution

RIF : 10mg/kg

RPT: 30mg/kg (single dose)

20mg/kg 9multiple-dose)

Optimizing experimental conditions: healthy rabbits

0

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20000

0 100 200 300 400 500

Co

nc.

of

RIF

(n

g/g

)

Conc. of lung tissue (mg/ml)

RIF in lung tissue

0

1000

2000

3000

4000

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6000

0 100 200 300 400 500

Co

nc.

of

RP

T (

ng

/g)

Conc. of lung tissue (mg/ml)

RPT in lung tissue

0

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20000

25000

30000

0 1 2 3 4 5 6 7 8 9 10111213141516

Co

nc.

of

RP

T(n

g/m

l o

r n

g/g

)

post IV-injection (hour)

plasma (ng/ml)

lung tissue(ng/g)

PK of RPT (30mg/kg)

in plasma and lung tissueCmax : 27µg/ml (0.5h)

AUC 0-15 : 100 µg*h/ml

T ½: 4.5h

In human plasma PK of single dose of RPT

(20mg/kg, oral administration)

Cmax : 25µg/ml (5h)

AUC 0-12 : 403µg*h/ml

T ½: 25.9 h

Clin Pharmacol Ther. 2012 May ; 91(5): . doi:10.1038/clpt.2011.323

Penetration of single dose of RIF (10mg/kg) by LC/MS : rabbits with TB disease

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20000

0 1 2 3 4 5 6 7

Co

nc.

of

RIF

(n

g/m

l o

r n

g/g

)

Post IV-injection (hour)

PK of RIF in plasma anddiseased lung

0

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12000

14000

2 3 6

Co

nc.

of

RIF

(n

g/g

)

Post IV-injection (hour)

Penetration of RIF in diseased lung

** • P<0.02

** p<0.01

*

*

C max : 17µg/ml

AUC 0-6 : 40 µg*h/ml

T ½: : 2h

UI : uninvolved lung tissue

SL : tissue surrounding lesion

LE: cellular lesion

CAC: caseum from necrotic lesion

In human plasma PK of single dose

(10mg/kg, oral administration)

C max : 10.5µg/ml

AUC 0-12 : 57.5 µg*h/ml

T ½: : 3h

Clin Pharmacol Ther. 2012 May ; 91(5): . doi:10.1038/clpt.2011.323

2h 3h 6h

MALDI-MSI and H&E staining of lung tissue: single dose of RIF

Necrotic lesion Cellular lesion Necrotic lesion

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60000

0 1 2 3 4 5 6 7

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nc.

of

RP

T (

ng

/ml

or

ng

/g)

Post IV-injection (hour)

PK of RPT in plasma anddiseased lung

Penetration of single dose of RPT (30mg/kg) by LC/MS :

rabbits with TB disease

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20000

30000

40000

50000

60000

70000

80000

2 3 6

Co

nc.

of

RP

T (

ng

/g)

Post IV-injection (hour)

Penetration of RPT in

diseased lung

*p <0.01

UI: uninvolved lung tissue

LE: cellular lesion

CAW: cavitary lesion (wall)

CAC: cavitary lesion (caseum)

SL: tissue surrounding lesion

**

C max : 50µg/ml

AUC 0-6 : 175µg*h/ml

T ½: : 4.5h

2h 3h 6h

MALDI-MSI and H&E Staining of lung tissue : single dose of RPT

cellular lesion cavitary lesion cavitary lesion

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0 30min 5h 30min 4h 30min 2h

First dose Second dose Third dose

Co

nc.

of

RIF

(n

g/m

l)

PK of RIF in plasma (M2h)

05000

100001500020000250003000035000400004500050000

0

30

min 4h

30

min 4h

30

min 4h

30

min

12

h

First dose Seconddose

Third doseForth dose

Co

nc.

of

RIF

(n

g/m

l)

PK of RIF in plasma (M12h)

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30000

M2h M12h

Co

nc.

of

RIF

(n

g/g

)

Penetration of RIF in different compartments of TB disease

UI: uninvolved lung tissue

LE: cellular lesion

CAW: cavitary lesion (wall)CAC: cavitary lesion (caseum)

SL: tissue surrounding lesion

AUC 0-12.5:241µg*h/ml AUC 0-26:431µg*h/ml

In human plasma PK of multiple-dose

(10mg/kg, oral administration, 14 days)

Cmax : 7.5µg/ml (5h)

AUC 0-12 : 45.2µg*h/ml

T ½: 2.4 h

Clin Pharmacol Ther. 2012 May ; 91(5): .

doi:10.1038/clpt.2011.323

Penetration of multiple-dose of RIF (10mg/kg) by LC/MS :

rabbits with TB disease

M2h

M12h

Uninvolved lung Cavitary lesion (1) Cavitary lesion (2)

Uninvolved lung Necrotic lesionCellular lesion

MALDI-MSI and H&E staining of lung tissue : multiple-dose of RIF

0

10000

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50000

60000

70000

80000

0 30min 3h 30min 3h 30min 3h 30min 2h

First dose Second dose Third dose Forth dose

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nc.

of

RP

T (

ng

/ml)

PK of RPT in plasma (M2h)

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0 30min 3h 30min 3h 30min 3h 30min 12h

First dose Second dose Third dose Forth dose

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nc.

of

RP

T (

ng

/ml)

PK of RPT in plasma (M12h)

UI: uninvolved lung tissue

SL: tissue surrounding lesion

LE: cellular lesion

CAW: cavitary lesion (wall)

CAC: cavitary lesion (caseum)0

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40000

50000

60000

70000

80000

M2h M12h

Co

nc

. o

f R

PT

(n

g/g

)

Penetration of RPT in different compartments of TB disease

Penetration of multiple-dose of RPT (20mg/kg) by LC/MS :

rabbits with TB disease

AUC 0-13: 494µg*h/ml AUC 0-23: 833µg*h/ml

In human plasma PK of multiple-dose

(20mg/kg, oral administration, 14 days)

Cmax : 34.1µg/ml (5h)

AUC 0-12 : 483 µg*h/ml

T ½: 16h

Clin Pharmacol Ther. 2012 May ; 91(5): .

doi:10.1038/clpt.2011.323

M2h

M12h

Uninvolved lung

Cavitary lesion (1) Cavitary lesion (2)Uninvolved lung

Cellular lesion

Necrotic lesion

MALDI-MSI and H&E staining of lung tissue: multiple-dose of RPT

Conclusions

• We have established the PK of IV RIF and IV RPT in rabbits; half-life of RPT

is much shorter in rabbits than humans. Data can be used to determine

human-equivalent dosing for subsequent single and multiple dose

experiments.

• Penetration into granulomatous lesions was excellent for both RIF and RPT

and drugs remained in this type of lesions longer than in healthy lung tissue.

• Penetration of RIF into caseum in necrotic or cavitary lesions was poor, but

accumulation of RIF in caseum can be achieved by giving multiple- dose of

RIF with longer exposure time, which is consistent with that in human

necrotic caseum.

• RPT penetrated into caseum even poorer than RIF in comparison to their

uninvolved lung tissue; multiple dosing with longer exposure time seemed

not to improve penetration of RPT into caseum during the observation time,

which remains to be confirmed in humans.

Brendan Prideaux1,et al. Nature medicine online 7 September 2015; doi:10.1038/nm.3937

JHU- Divisions of Clinical Pharmacology and

Infectious Diseases

Dr. Kelly Dooley

JHU- Bishai laboratory (rabbit model)

Mike Urbanowski

Robyn Becker

Haidan Guo

Laurene Cheung

Brian Luna

Bill Bishai

JHU-Clinical Pharmacology Analytical Laboratory (tissue/plasma PK)

Teresa Parsons

Thuy Hoang

Mark Marzinke

JHU-Jain laboratory (PET imaging)

Mariah Klunk

Peter DeMarco

Alvaro Ordonez

Sanjay Jain

Rutgers (MALDI)

Brendan Prideaux

Veronique Dartois

UCSF (mathematical modeling)

Rada Savic, pharmacometrician

NIH/DAIDS

ACTG Novel Formulations Award

Acknowledgements