Directed therapy for fungal infections - latest advances

Rosemary BarnesFocus on aspergillosis

Problem

Antifungal expenditure is completely out of proportion with the scale of the problem Incidence of IFD in ICU (candida)

<0.6% Aspergillus infection in

haematological malignancy (0.5-12%) Aspergillus in SOT <5%

Harrison D et al Fungal Infection Risk Evaluation (FIRE) Study. Health Technol Assess 2013; 17(3).Pagano L et al. Haematologica 2006; 91: 1068-1075Pagano L et al. Clin Infect Dis 2007; 45: 1161-1170

Total UK antifungal expenditure c £112 million

Rising by 9% pa

Reasons Infection associated with significant

morbidity and mortality Signs and symptoms of systemic

infection are nonspecific Conventional diagnostic techniques are

suboptimal Delays in treatment associated with

poorer outcome

Choices choices choices

Diagnosis

Empirical therapy

Change antibiotics

Febriledespite

antibiotics

Fever

yes

no

Decision tree

Fever No diagnosis

yes

yes

no

no

yes

no

Decision tree

Fever AnxietyNo diagnosis

yes

yes

yes

yesno

no

no

no

yes yes

yes

nono

no

Decision tree

Fever Out of hoursAnxietyNo diagnosis

yes

yes

yes

yesno

no

no

no

no

no

yes

yes

yes

yesno

no

yes yes

yes

nono

no

no

no

no

yes

yes

yes

yes

no

Decision tree

Fever Out of hoursAnxietyNo diagnosis

yes

yes

yes

yesno

no

no

no

no

no

yes

yes

yes

yesno

no

yes yes

yes

nono

no

no

no

no

yes

yes

yes

yes

no

Decision tree

No therapy

Empirical therapy

include all patients likely to have invasive fungal infection and treat them with the safest and most effective drug

Aim of a directed strategy

exclude all patients unlikely to have invasive fungal disease and adopt a WAIT-and-SEE policy

Maertens et al. (2012) Haematologica 97(3): 325-327.

Consensus criteria Aimed to provide definitions for proven,

probable and possible fungal infection that could facilitate clinical research

Designed for use in clinical trials Highly selective population Not representative of real life clinical practice Focus on specific radiological signs

Focus on defining DISEASE needs to shift towards INFECTION Needs a diagnostic approach

biomarkersDe Pauw et al CID

2008, 46

The biomarkers Antigen tests

Galactomannan (aspergillus) Beta D glucan (pan-fungal-ish) Lateral flow device

Molecular Aspergillus specific Panfungal Commercial (…….)

Galactomannan - in serum useful test in surveillance: high NPV Performance in

haematological malignancy better than in SOT neutropenic > corticosteroid treated group Adults >children

Influenced by pre-test probability (ie sensitivity increases with prevalence)

EORTC/MSG criteria heavily dependent on test being performed

Recommended by ECIL

Galactomannan – meta-analyses

30 studies > 7000 patients Prevalence 7.7% sensitivity78% (61% to 89%) specificity 81% (72% to 88%).

cut-off 0.5: 100 patients: 2 patients with IA, will be missed, 17 patients will be treated unnecessarily

cut-off 1.5 OD: 3 IA patients will be missed 5 patients will be treated unnecessarily

results were very heterogeneous. Insufficient data to look at clinical

utility

http://www.thecochranelibrary.com

PUO GM pos CT BAL

Pre test probabilityPre test probability

Maertens et al CID 2009

BAL

0.5 approved by FDA On the basis of clinical validity

PPV of GM BAL is 100% at an OD index cutoff of ≥3 only 76% at ≥ 0.5 (but NPV is high)

Beta D Glucan 4 different commercial tests

Heterogenous data : retrospective vs. prospective; Different cut offs “panfungal” – except cryptococcus and mucoracous

moulds Sensitivity, specificity variable but NPV high

High false-positives: up to 30% - bacteraemia, antibiotics, pre-/analytical contaminations

complex analytical procedures Analytical validity established Utility data limited Included in EORTC/MSG criteria

Beta D Glucan-meta-analysis

16 studies in 2979 patients Included case-controlled studies Included critical care, HM and

solid organ cancer patients Cut off 10-1000 pg/ml

Sensitivity 76.8% (67.1%–84.3%)

specificity 85.3% (79.6%–89.7%)

“area under ROC curve 0.89” “good diagnostic accuracy”

Karageorgopoulos et al Clin Infect Dis 2011;52(6):750

PCR The UK Fungal PCR consensus group

2004 technically validated candida PCR Made recommendations for aspergillus PCR

2006 European Aspergillus PCR Initiative set up 86 participants in 69 centres in 24 countries defined a standard for PCR for Aspergillus

Whole blood Serum plasma

optimal methodology to evaluate the performance and impact

QCMD availableWhite et al J Molec Diagn 2006; 8: 376White et al J Clin Micro 2010: 48 1231www.eapcri.eu/

NOTE: Weights are from random effects analysis

.

.

Overall (I-squared = 57.1%, p = 0.001)

Halliday 2006

Study

Ferns 2003

Scotter 2005

Williamson 2000

PCR=>2pos

ID

Kawazu 2004

Williamson 2000

Raad 2002

Buchheidt 2004

Buchheidt 2001

Stenghele 2006

El-Mahallawy 2006

Ferns 2003

Lass-Floerl 2004

Subtotal (I-squared = 52.9%, p = 0.030)

White 2006

Halliday 2006

Stenghele 2006

Subtotal (I-squared = 62.4%, p = 0.001)

Hebart 2000 JID

Hebart 2000 BJH

Buchheidt 2004

Jordanides 2005

Florent 2006

Kawazu 2004

PCR=>1pos

16.00 (8.60, 29.79)

81.00 (4.54, 1443.84)

0.75 (0.05, 11.31)

55.00 (2.44, 1238.39)

325.00 (12.25, 8623.71)

OR (95% CI)

7.61 (0.94, 61.24)

93.00 (4.58, 1889.51)

177.29 (8.35, 3765.07)

3.04 (0.84, 11.06)

47.88 (13.87, 165.35)

8.66 (1.02, 73.47)

33.75 (8.90, 128.02)

1.33 (0.09, 20.11)

1.43 (0.34, 6.08)

15.97 (6.83, 37.34)

211.50 (24.37, 1835.39)

24.51 (1.39, 430.66)

12.50 (2.58, 60.45)

16.41 (6.43, 41.88)

53.28 (2.87, 989.20)

139.92 (7.21, 2716.71)

6.86 (1.65, 28.50)

7.97 (1.52, 41.74)

15.17 (6.00, 38.34)

11.92 (3.13, 45.34)

100.00

3.08

%

3.32

2.77

2.57

Weight

4.48

2.90

2.84

6.51

6.66

4.37

6.40

3.32

6.07

44.60

4.32

3.10

5.73

55.40

3.02

2.96

6.14

5.51

7.54

6.39

16.00 (8.60, 29.79)

81.00 (4.54, 1443.84)

0.75 (0.05, 11.31)

55.00 (2.44, 1238.39)

325.00 (12.25, 8623.71)

OR (95% CI)

7.61 (0.94, 61.24)

93.00 (4.58, 1889.51)

177.29 (8.35, 3765.07)

3.04 (0.84, 11.06)

47.88 (13.87, 165.35)

8.66 (1.02, 73.47)

33.75 (8.90, 128.02)

1.33 (0.09, 20.11)

1.43 (0.34, 6.08)

15.97 (6.83, 37.34)

211.50 (24.37, 1835.39)

24.51 (1.39, 430.66)

12.50 (2.58, 60.45)

16.41 (6.43, 41.88)

53.28 (2.87, 989.20)

139.92 (7.21, 2716.71)

6.86 (1.65, 28.50)

7.97 (1.52, 41.74)

15.17 (6.00, 38.34)

11.92 (3.13, 45.34)

100.00

3.08

%

3.32

2.77

2.57

Weight

4.48

2.90

2.84

6.51

6.66

4.37

6.40

3.32

6.07

44.60

4.32

3.10

5.73

55.40

3.02

2.96

6.14

5.51

7.54

6.39

1.0001 1 10000

Mengoli et al Lancet Infectious Diseases. 2009; 9: 89-96

PCR

Single negative PCR to exclude disease

2 consecutive PCRs to diagnose IA

Sensitivity 88% Specificity 75% DOR22

“Directed/pre-emptive” therapy

References Country Clinical HRCT GMMicro-

biologicalPCR

Non-comparative studies

Maertens 2005 Belgium X X X

Girmenia 2010 Italy X (X) X

Aguilar-Guisado 2010 Spain X X X

Barnes 2009 UK X X X X

Dignan 2009 UK X

Randomised, comparative studies

Cordonnier 2009 France X X (X)

Hebart 2009 Germany X

Observational studies

Pagano 2012 Italy X (X)

Galactomannan EIA

Open study 136 episodes of

neutropenia Patients receiving flucon

prophylaxis daily EIA GM + early CT

scanning in neutropenic febrile episodes

Antifungal given if 2 consecutive EIA GM results +ve (index ≥ 0.5)

and confirmed by BAL or CT Maertens et al. Clin Infect Dis 2005; 41: 1242

Maertens et al 35% of episodes met criteria for empirical

antifungal but only7.7% treated on basis of pre-emptive therapy

Duration of fever not affected 22 cases of IFD only one missed 3 breakthrough infections

2 candidaemias 1 mucorales

No excess mortality or fungal related death No impact on overall antifungal usage

despite deceased empirical use

Cordonnieret al CID 2009 48:1043

293 patients randomised empirical or pre-emptive therapy empirical arm received antifungals if they had

persistent/recurrent fever after 4 days pre-emptive patients given antifungal only if they

showed clinical and radiological signs of pneumonia/sinusitis positive GM index ≥ 1.5 Aspergillus colonization Septic shock CNS signs/periorbital inflammation Diarrhoea/mucositis ≥ grade 3 fever > 14 days

Cordonnieret al

Survival was not significantly “Non inferiority” demonstrated pre-emptive patients had more IFI

9.1% vs 2.7% pre-emptive patients received

significantly less antifungals no significant cost savings were

achieved Used ampho B deoxycholate first -line

Empirical vs. pre-emptive antifungal therapy

Empirical

Pre-emptive

IFI in Pre-emptive

IFI in Empirical

Cordonnier et al, Clin Infect Dis, 2009; 48: 1042-1051

Pagano et al Haematologica 2011; 96:1363

Observational: Empiric versus “pre-emptive” Data collection 397 HM patients

190 empiric ; 207”pre-emptive” More IFD in pre-emptive arm Increased mortality and antifungal use in

“pre-emptive arm” Fever driven, no screening, diagnostic work

up not standardized some GM usage, no PCR Pre-emptive group largely diagnosed on basis of

HRCT

PCR randomised

study of a PCR directed versus an empirical antifungal

more than 400 SCT patients

Safe Improved

survival at 30 days (not 100)

No reduction in antifungal drug use.

Nested PCR to guide antifungal therapy 42 patients with

cancer, neutropenia

AmB required in only 2 patients

Hebart et al. Blood 2004;104: 59A.

Lin et al. Clin Infect Dis. 2001;33:1621-1627

In Cardiff 549 high-risk haematology patients entering

neutropenic pathway 2005-2010 audited and followed up for a minumum of 12

months Twice weekly antigen and PCR testing (or GvHD) Itraconazole prophylaxis or AmBisome 7mg/kg/weekly Empiric antifungals not used unless

Clinical/mycological evidence of disease Itraconazole levels were subtherapeutic or unmeasured

First 125 patients analysed for safety and proof of concept

Data collected on compliance, incidence of IFD and efficacy of prophylaxis

Barnes et al Journal of Clinical Pathology 2009

Incidence of IFD (2005-2011) Invasive aspergillosis 9.6%

6 histologically proven (2 postmortem) 4 pulmonary (2 with dissemination) 2 invasive sinusitis

47 probable (23 possible IA)

Invasive Candidal infection 2% 12 proven

4 C. albicans, 3C. glabrata, 2C. tropicalis, 1C. parapsilosis, 1C. guilliermondii, 1 mixedC. albicans + C. glabrata

1 probable 2 non-aspergillus moulds

1 Mucoraceous mould, 1 Scedosporium prolificans Incidence of proven/probable IFD 12.3%

IA disease status of subjects

By EORTC/MSG diagnostic criteriaProven – 6Probable – 47Possible – 23NEF – 473

• 248 of NEF showed some signs suggestive of IA

• EIA positive n=36• PCR positive n=136• EIA and PCR positive n=75

• Aspergillus isolated n=5

Diagnostic accuracy Explore analytical validity. Clinical

validity, clinical utility Sensitivity specificity PPV, NPV, LR, DORs

Use ROC analysis to explore different thresholds for defining “cases”

EORTC/MSG EORTC – GM EIA EORTC + PCR Dual biomarker positivity Multiple positives versus single

Population AssayPositivity

ThresholdSensitivity (%) Specificity (%) PPV (%) NPV (%) LR+ LR- DOR

Provena, probableb vs No IFDc EIA

Single 96.2 (87.3-99.0) 76.7 (72.7-80.3) 31.7 (25.0-39.2) 99.5 (98.0-99.9) 4.14 0.05 84.15

Multiple 62.3 (48.8-74.1) 91.8 (88.9-93.9) 45.8 (34.8-57.3) 95.6 (93.3-97.1) 7.55 0.41 18.36

Provena, probableb, possibled

vs No IFDc EIA

Single 67.1 (55.9-76.6) 76.7 (72.7-80.3) 31.7 (25.0-39.2) 93.6 (93.7-97.6) 2.89 0.43 6.73

Multiple 43.4 (32.9-54.6) 91.8 (88.9-93.9) 45.8 (34.8-57.3) 91.0 (88.1-93.2) 5.27 0.62 8.54

Provena, probable

incorporating PCRe vs No IFDc

EIASingle 72.9 (61.5-81.9) 76.7 (72.7-80.3) 31.7 (25.0-39.2) 95.0 (92.4-96.8) 3.13 0.35 8.86

Multiple 47.1 (35.9-58.7) 91.8 (88.9-93.9) 45.8 (34.8-57.3) 92.1 (89.4-94.3) 5.72 0.58 9.93

Provena, probableb vs No IFDc PCR

Single 92.5 (82.1-97.0) 55.6 (51.1-60.0) 18.9 (14.6-24.1) 98.5 (96.2-99.4) 2.08 0.14 15.34

Multiple 73.6 (60.4-83.6) 79.9 (76.1-83.3) 29.1 (22.1-37.3) 96.4 (94.1-97.9) 3.66 0.33 11.08

Provena, probableb, possibled

vs No IFDc PCRSingle 86.8 (77.5-92.7) 55.6 (51.1-60.0) 23.9 (19.3-29.3) 96.3 (93.4-98.0) 1.96 0.24 8.27

Multiple 65.8 (54.6-75.5) 79.9 (76.1-83.3) 34.5 (27.2-42.5) 93.6 (90.7-95.6) 3.28 0.43 7.65

Provena, probable

incorporating PCRe vs No IFDc

PCRSingle 94.3 (86.2-97.8) 55.6 (51.1-60.0) 23.9 (19.3-29.3) 98.5 (96.2-99.4) 2.12 0.10 20.66

Multiple 71.4 (60.0-80.7) 79.9 (76.1-83.3) 34.5 (27.2-42.5) 95.0 (92.4-96.7) 3.56 0.36 9.95

Provena, probableb vs No IFDc

PCR or ELISA

Single 98.1 (93.4-100) 47.8 (42.0-53.5) 17.4 (11.9-22.9) 99.6 (98.5-100) 1.88 0.04 47.6

Multiple 79.2 (65.3-93.2) 76.7 (71.9-81.6) 27.6 (0.19-36.7) 97.1(94.9-99.2) 3.41 0.27 12.6

Provena, probableb, possibled

vs No IFDc

PCR or ELISA

Single 90.8 (82.5-99.1) 47.8 (42.0-53.5) 21.8 (16.0-27.6) 97.0 (94.2-99.8) 1.74 0.19 9.0

Multiple 69.7 (56.6-82.9) 76.7 (71.9-81.6) 32.5 (23.341.7) 94.0 (91.0-97.1) 3.00 0.39 7.6

Provena, probable

incorporating PCRe vs No IFDc

PCR or ELISA

Single 98.6 (92.3-100) 47.8 (42.0-53.5) 21.8 (0.17-0.28) 99.6 (96.1-100) 1.89 0.03 63.13

Multiple 90.0 (80.8-95.1) 76.7 (71.9-81.6) 36.4 (27.6-46.2) 98.1 (95.5-99.3) 3.87 0.13 29.7

Provena, probableb vs No IFDc

Both PCR and

ELISA

Single 90.6 (79.8-95.9) 84.4 (80.8-87.4) 39.3 (31.1-48.2) 98.8 (97.1-99.5) 5.79 0.11 51.76

Multiple (1 assay) 71.7 (56.2-87.2) 87.7 (84.0-91.5) 39.6 (27.1-52.1) 96.5 (94.3-98.7) 5.85 0.32 18.13

Multiple (both assays) 56.6 (43.3-69.1) 94.9 (92.6-96.6) 55.6 (42.4-68.0) 95.1 (92.8-96.7) 11.16 0.46 24.40

Provena, probableb, possibled

vs No IFDc

Both PCR and

ELISA

Single 63.2 (51.9-73.1) 84.4 (80.8-87.4) 39.3 (31.1-48.2) 93.4 (90.7-95.4) 4.04 0.44 9.24

Multiple (1 assay) 50.0 (35.7-91.5) 87.7 (84.0-91.5) 39.6 (27.1-52.1) 91.6 (88.4-94.90 4.08 0.57 7.16

Multiple (both assays) 39.5 (29.3-50.7) 94.9 (92.6-96.6) 55.6 (42.4-68.0) 90.7 (87.8-93.0) 7.78 0.64 12.20

Provena, probable

incorporating PCRe vs No IFDc

Both PCR and

ELISA

Single 68.6 (57.0-78.2) 84.4 (80.8-87.4) 39.3 (31.1-48.2) 94.8 (92.2-96.5) 4.38 0.37 11.76

Multiple (1 assay) 54.3 (39.4-69.2) 87.7 (84.0-91.5) 39.6 (27.1-52.1) 92.8 (89.8-95.9) 4.43 0.52 8.5

Multiple (both assays) 42.9 (31.9-54.5) 94.9 (92.6-96.6) 55.6 (42.4-68.0) 91.8 (89.1-93.9) 8.45 0.60 14.03

Statistical parameters

Sensitivity

Specificity PPV NPV LR+ LR- DOR

Proven, probable vs No IFD

PCR or GM EIA

Single 98.1 47.8 17.4 99.6 1.88 0.04

47.6

multiple

79.2 76.7 27.6 97.1 3.41 0.27

12.6

PCR and GM EIA

single 90.6 84.4 39.3 98.8 5.79 0.11

51.76

multiple

56.6 94.9 55.6 95.1 11.16 0.46

24.4

By EORTC/MSG criteria

Proven/probable disease versus no IFDDiagnostic odds ratio

Ascertainment biasE

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0

10

20

30

40

50

60

70

80

90

EORTC EORTC minus GM EORTC plus PCR

Positive likelihood ratio

02468

10121416

EORTC

EORTC minus GM

EORTC plus PCR

15.8

11.210.5

Negative likelihood ratio

0

0.1

0.2

0.3

0.4

0.5

0.6

EORTC

EORTC minus GM

EORTC plus PCR

0.030.05

ROC plot

curve (AUC): 0.910 (95% CI: 0.872-0.948)

PCR + EIA

Proven/prob/possProven/prob

Performance of PCR

Utility in proven/probable n=53 First marker positive

PCR in 23 EIA in 15 PCR and EIA simultaneously positive in 7 radiological features in 8

In 85% biomarkers preceded specific radiological signs (range 1-118d)

Diagnostic accuracy Screening by PCR AND GM EIA can enable a

diagnosis of IA to be excluded

Positive PCR +GM EIA or multiple positive PCRs or EIAs can be used to accurately diagnosis IA

specificity 84.4%; sensitivity >90% DOR>50

Biomarkers are earliest markers in 85% of cases

Use antifungals more cost effectively

Antifungal expenditure

Similar units typically spending £1-2 mill pa

2005 2006 2007 2008 2009 2010 £0.00

£50,000.00

£100,000.00

£150,000.00

£200,000.00

£250,000.00

£300,000.00

£350,000.00

£400,000.00

Total Antifungal expenditure

Linear (Total Anti-fungal expendi-ture)

Cost of testing

Linear (Cost of testing)

Use of biomarkers

Regular screening throughout period or risk

Screening during fever only Diagnostic testing during

refractory fever only Confirmation when specific

radiological signs are present None - empiric therapy

Strategy Used

Influenced by Risk of IFD

Prevalence affects utility of diagnostic tests

ECIL recommend screening if IFD 5-10%

Prophylaxis used Mould active reduces utility of diagnostic

tests Availability of

Diagnostic tests Protective environments/HEPA filtered air

Incidence of IFD after posaconazole therapy

Pagano et al Haematological 2012; 97:963

Effect of antifungal therapy

Group

Days post infection

1 2 3 4 5

Test

qPCR

GM PCR GM PCR GM PCR GM PCR GM

Infected controls

2/3 0/3 3/3 1/3 3/3 3/3 3/3 3/3

Amphotericin B 2/3 1/3 3/3 3/3 3/3 3/3 3/3 3/3

Caspofungin 1/3 1/3 1/3 3/3 2/3 3/3 3/3 2/3

Posaconazole 1/3 0/3 1/3 2/3 3/3 3/3 1/3 2/3

Uninfected controls

0/3 0/3

McCulloch et al J Clin Path 2012; 65:83 Marr K A et al. Clin Infect Dis. 2005;40:1762-1769

Example

High risk patientPrevalence8- ≥10%

No Mould active prophylaxis – Screening regime

Mould active prophylaxis used – Diagnostic regime

Twice weekly screening of blood samples:

Galactomannan,And Aspergillus PCR

HRCT and BAL when infection suspectedDiagnostic testing during refractory fever with Beta D glucan

(serum) and Aspergillus PCR (BAL and blood or serum), galactomannan

(BAL and serum)

Targeted antifungal therapy for clinically diagnosed infection only with

biomarker confirmation

Single Positive biomarkerContinue screening process

>1 biomarker positive* triggers diagnostic workup to include relevant radiology and BAL if

indicated

No consistent clinical signs or symptoms indicates need for possible

pre-emptive therapy

Any consistent clinical signs or symptoms indicates need for antifungal

therapy

*For example: PCR and GM, or Multiple GM

at risk infection disease

Prophylaxis

Pre-emptive Targetted

exposure

Any Questions?