Confronting Cryptococcal meningitis in Africa: New diagnostic, prevention and treatment strategies

to reduce disease burden

Tom Harrison

Meningitis Research Foundation

November 5th, 2013

Plan:• Epidemiology

• ongoing burden HIV-associated CM (non HIV CM)• Diagnostics

• New LF point-of-care dipstick test for CrAg• Use in screening, early diagnosis

• Therapy• Current options:• Developed and Resource-limited settings• Ongoing and future studies

• [Mnx of complications: CM-IRIS, timing ART (COAT study), raised CSF pressure. Immunology of HIV-CM, virulence & evolution C. neoformans]

HIV-associated cryptococcal infection:

• Accounts majority global burden of CM• Cryptococcal meningitis: common in late stage HIV• Treatment is poor – > 50% 10 wk mortality in Africa

• Common cause of death in HIV cohorts - around 15% all HIV deaths S/E Africa

• At least 100,000 deaths/yr in SSA: CDC – CID 2009; 23:525

• Not decreasing yet with ART in most centres• But ART means good long term prognosis if survive

acute infection

Cape Town, South Africa Kampala, Uganda

Jarvis J et al. BMC Inf Dis 2010

Aetiology of Adult Meningitis in S/E Africa

Durski K et al. JAIDS 2013

Source: National Institute for Communicable Diseases, Johannesburg, SA

S Africa: high CM burden despite ART rollout

Bicanic et al CROI 2011 P-150, Submitted

• Problem: Late presentation. Need: Earlier Diagnosis

• Early features – headache, fever v. non specific – patients often not referred immediately to hospital for LP – by which time may be too late for effective Rx

• Need Point-of-Care diagnostic test• Polysaccharide capsule - major virulence factor but also

?Achilles heel of Cryptococcusbasis specific, early (subclinical stage) diagnostic test (Latex agglutination assay CrAg)

• POC format Immuno-Mycologics (Sean Baumann, CEO), Tom Kozel (Univ. of Nevada at Reno):

LFI dipstick for GXM. LFI was constructed using a cocktail of mAbs F12D2 and 339KOZEL LAB.The assay has a sensitivity of 2-5 ng/ml for serotype A GXM:

Table 3. Sensitivity limits of a prototype LFI assay (constructed by IMMY) for GXM of serotypes A, B, C and D compared with commercially available latex agglutination assaysa

ImmunoassaySerotype Ab Serotype B Serotype C Serotype D

CN6 MU-1 184 4092406

6KC 298

9375 127

Prototype LFI assay

2.4 5.0 4.6 3.0 16 7.0 10 5.1

Commercial latex agglutinationc

250 500 500 250 8,000 4,000 1000 250

a Results reported as the lowest GXM concentration (ng/ml) producing an unequivocal positive resultb Results are shown for GXM from two strains of each cryptococcal serotypec Results from commercial latex agglutination assays are the median result from evaluation of kits from three different manufacturers

Jarvis et al CID 2011; 53:1019

Crag Lateral Flow Assay

CrAg LFA test for serum, CSF (samples already approved for latex agglutination test) approved in Europe, and now by FDA

But, ideally need test using non-invasive sample, with no processing

Urine

Drop whole blood

Concentration of GXM in paired serum, plasma and urine from 25 subjects.

Blood and urine were collected from 25 patients in Cape Town with culture proven cryptococcosis. Serum, plasma and urine were evaluated by quantitative ELISA to assess concentrations of GXM.

Jarvis et al CID 2011; 53:1019

Sensitivity of Urine vs Plasma/Serum LFA in culture-confirmed cases CM - Cape Town

Retrospective Study:Cryptococcus culture-confirmed paired serum, plasma and urine specimens from 62 South African patients in Cape Town

Serum Plasma Urine

Crag LFA (+) 61 61 61

Crag LFA (+/-) 1 1 0

Crag LFA (-) 0 0 1

Crag LFA Serum Plasma Urine

Sensitivity 100% 100% 98%

95% CI 94-100% 94-100% 91-100%

Jarvis et al CID 2011; 53:1019

• POC could be used:• Facilitate earlier diagnosis (in primary care settings) and

treatment all symptomatic cases

• Prevention clinical CM by screening for subclinical infection and pre-emptive treatment

• Targeted use pre-emptive fluconazole therapy for patients with CD4<100 who are CrAg positive, after HIV diagnosis and prior to starting ART:

an alternative strategy to primary “across-the-board” fluconazole prophylaxis

Jarvis et al: Clin Infect Dis 2009; 48:856

• In South Africa• 20-33% of cases now present after initiation of ART• Over 70% present after a diagnosis of HIVBicanic CID 2007; 45:76 Jarvis CID 2010; 51:1463

• All these cases are potentially preventable

• Screening identifies those patients at risk :

Jarvis et al: Clin Infect Dis 2009; 48:856

Serum Antigen positive (approx 5-10% of CD4<100)

28% developed meningitis

Serum Antigen negative (90%+ of CD4<100)

0/660 patients developed meningitis

Current Gold Standard Therapy: Amphotericin B plus Flucytosine

IDSA Perfect et al CID 2010 50:291-322,

WHO Rapid advice guideline, WHO November, 2011:

2 wks:

AmB 0.7-1 mg/kg/d plus flucytosine (5-FC) 100 mg/kg/d

Based on..Van der Horst et al NEJM 1997; 337:15

Supported by…Brouwer et al: Lancet 2004; 363:1764-67

Nailed by….Day et al NEJM 2013; 368:1291-302

• Vietnam trial, Day et al

Induction with:• AmB 1 mg/kg/d alone, 4 weeks• Vs AmB 1 mg/kg/d alone plus 5FC 100 mg/kg/d, 2 weeks• Vs AmB 1 mg/kg/d alone plus fluconazole 800 mg/d, 2

weeks

• To clinical endpoints [n=300]• Results presented ICAAC last year, NEJM April 2013

Day J et al ICAAC 2011

Vietnam trial, Jeremy Day et al [ISRCTN95123928]

AmB+5FC

AmB aloneAmB+flucon

Amphotericin B combinations

Given availability (low or no cost), safety fluconazole, but current lack access 5FC

Important question for high burden countries in Africa in particular is:

Is AmB plus fluconazole preferable to AmB alone?

Day J et al N Engl J Med 2013;368:1291-302

Vietnam trial, Jeremy Day et al

Vietnam trial plus Pappas et al: CID 2009; 48 1775-83

in the absence of 5FC…

AmB 1 mg/kg/d plus fluconazole 800 mg/d

Southern African J HIV Med 2013; 14:76

Antifungal therapy: New Paradigms in resource-restricted settings

Problem

1. accepted gold standard 2 wks AmB+5FC not available, feasible in many African centres

2. currently widely-used and available alternative oral fluconazole - inadequate

Bicanic T et al, Clin Infect Dis 2007; 45:76-80.

Log C

FU

/ml C

SF

2 4 6 8 10 12 14 160

1

2

3

4

5

6

7

Day

Lo

g C

FU

/ml C

SF

2 4 6 8 10 12 14 160

1

2

3

4

5

6

7

Day

Lo

g C

FU

/ml C

SF

Fluconazole 800EFA -0.08 logCFU/d

Fluconazole 1200EFA -0.18 logCFU/d

No increased toxicity observed – small numbers

Longley, Muzoora, et alClin Infect Dis 2008; 47 1556-61

Patients from Cape Town

Nussbaum et al. Clin Infect Dis 2010; 50:338-44

UNC Project, Lilongwe, Malawi

Nussbaum et al. Clin Infect Dis 2010; 50:338-44

2 week mortality: HR 0.24 (0.05-1.16) p=0.05

Alternative, resource-restricted centres:

Add Short course AmB (5-7 days)Cohorts in Mbarara, Uganda (5 d) and Lilongwe, Malawi (7d) (Muzoora et al J.Infect 2012, Jackson et al, AIDS 2012)

•Very large gain: TolerabilityFeasibility, sustainability

•?Would efficacy be compromised?Large initial reduction in organism loadCarries on through second week - with no flattening

?long half life AmB Follow up therapy: high dose fluconazole

Muzoora et al: J Infect 2012; 64:7630 patients Rx 1200 mg/d flucanozole plus AmB 1 mg/kg/d 5 days: EFA -0.30 log CFU/d over 2 weeks, -0.31 over 7 days

Gain in tolerability::

no grade III/IV anemia, ALT, no grade IV hypokalaemia, creatinineTrends in mortality: compared earlier Mbarara cohorts: 2 and 10 wks: 23%, 28%

ACTA Trial: MRC funded: MLW Blantyre, UNC Lilongwe, UTH Lusaka; ANRS: Cameroon

Strategy 1: Fluconazole 1200 mg /d plus flucytosine 25 mg/kg qds for 2weeks.

Strategy 2: Amphotericin B (AmB) 1 mg/kg/d + fluconazole 1200 mg /d OR 5FC for 7 days

Strategy 3: Amphotericin B (AmB) 1 mg/kg/d + fluconazole 1200 mg /d OR 5FC for 14 days

Potential Impact

Strategies 1, 2, much more readily, safely sustained than 3.

IF either shown to be as effective as 3, could result in a reduction in the 10-week mortality in resource-limited settings using fluconazole from around 50-60%

to the 30-35% seen with 2 wk AmB-combination treatment.

IF NOT as effective then substantial extra resources to SAFELY deliver 2 wks AmB-combination Rx are justified

Other ongoing studies

Adjunctive Steroid study CRYPTODEX (Jeremy Day, David Lalloo and colleagues)

ACTG 5225: Fluconazole dose escalation (1200g-2000g/d) vs AmB. (Bob Larsen and colleagues)

Other planned / ongoing studies

Phase II: 3rd Strategy building on high dose fluconazole backbone – adding

Intermittent high dose Ambisome – 1, 2, or 3 doses, vs standard daily dosing Ambisome, with EFA endpoint.

Joe Jarvis, et al. Mwanza Tanzania.

Loyse A et al. Lancet Infect Dis. 2013 Jul;13(7):629-37

CMAG - cryptococcal meningitis action group

GAFFI – Global Action For Fungal Infections - David Denning and colleagues

AmB and 5FC from 2013 on WHO essential medicines list

St. George’s

Tihana Bicanic

Joe Jarvis

Angela Loyse

Nicky Longley

Sile Molloy

Annemarie Brouwer

Thailand

Nick White, Nick Day

Funders:

Wellcome Trust

MRC

USAID

DFID Malawi

British Infection Society

Lancet

ANRS

South Africa

Graeme Meintjes,

Linda-Gail Bekker, Robin Wood

Mbarara, Uganda

Conrad Muzoora, Kabanda Taseera Lilongwe Malawi, UNC Project

Jesse Nussbaum, Charles Van der Horst, Dan Namarika, Mina Hosseinipour

Blantyre, MLW, CoM: Rob Heyderman, David Lalloo, Kate Gaskell

Lusaka UTH: Shabir Lakhi, Duncan Chanda

Cameroon: Charles Kuouanfack, Elvis Temfack

Pasteur Institute: Olivier Lortholary

London School Hygiene Tropical Medicine

Shabbar Jaffar, John Bradley

University Nevada, Reno: Tom Kozel

Immuno-Mycologics: Sean Baumann