Affordable tests for HIV drug resistance and HIV viral load in Africa Prof Tobias Rinke de Wit

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1 Affordable tests for HIV drug resistance and HIV viral load in Africa Prof Tobias Rinke de Wit 6 th INTEREST Workshop Mombasa, Kenya, May 8-11, 2012

2 The roll-out of ART in resource poor settings has followed a public health approach (WHO): Simplified guidelines to antiretroviral treatment (ART) Limited and simplified laboratory monitoring

3 Simplified ART guidelines ARV drugs approved by FDA In Africa: 90% of 1 st line patients are on combinations of only 6 drugs: 3TC, d4t, AZT, TDF, EFV, NVP 1 st line regimens in RLS 2 nd line regimens in RLS WHO Progress Report

4 Worldwide ART coverage Coverage >95% in Rwanda Namibia Botswana WHO Progress Report

5 Downside of mass ART in RPS: risk of HIVDR Intermittent drug supply, stock-outs Patient adherence challenges, weak patient support systems HR challenges (task shifting) Use of sub-optimal regimens (single dose NVP for PMTCT) Use of less costly ARV s with higher toxicity (d4t) Drug interactions (NVP-rifampicin) High viral genetic diversity: subtypes HIVDR? Late reporting of patients Lack of virological monitoring

6 HIVDR is actually emerging in Africa Hamers RL et al. Published online July 28, 2011 DOI: /S (11)

7 Simplified lab monitoring

8 Downside of simplified (non-vl) monitoring 7

9 No VL unnecessary switching N=268 Clinical parameters+ CD4 count Clinical parameters+ CD4 count + viral load Sigaloff et al JAIDS

10 Delayed switch more HIVDR PASER patients with prolonged 1 st line ART failure (~2 years with VL>1,000): 88% (161/183) at least 1 HIVDR 82% (149/183) dual class HIVDR 2% (3/183) triple class HIVDR 48% (90/183) NRTI cross resistance consequences for 2 nd line (NRTI + LPV/r) Need for targeted VL and HIVDR testing Time Sigaloff et al JAIDS

11 New WHO recommendations If resources permit: Targeted VL to confirm drug failure based on clinico immunologic criteria. OR Viral load every six months Switch to 2nd line when VL>5,000 cp/ml Qualitative!! 10

12 HIV VL + DR Tests: what are the Barriers? Technically complex Kit-dependent Sophisticated equipment Skilled staff needed Special lab infrastructure required Only on plasma Not all HIVDR mutations known Mainly subtype B adapted Expensive 11

13 Terms of Reference for the Test Significantly more affordable than current commercial HIVDR assays (equipment + kits). Robust, easy to use, relatively little laboratory training required. Cold-chain independent, preferably based on dried blood spots. Independent of HIV variability (subtypes). Sufficiently sensitive (>5,000 copies/ml). Intellectual property-protected 12

14 Strategy #1: DBS to collect and store samples

15 Strategy #2: DBS linked to Real Time PCR

16 Strategy #3: Qualitative VL as tiebreaker 5 LTR gag pol vif vpr vpu rev tat env nef 3 LTR MGB Probe 520* 600 * Drosten et al (2006) Clinical Chemistry Qualitative VL test based on conserved LTR subtype independent Affordable qualitative VL test can help avoiding unnecessary switching to 2 nd line

17 Strategy #4: Customized protocols for different categories of service providers A A: viral load, genotying + interpretation B B: Qualitative VL, genotype interpretation C C: Qualitative VL D D: DBS, VL interpretation E E: DBS, VL interpretation

18 Strategy #5: HIVDR ultralight Concentrate on target of ART in Africa: RT Africa >95% of HIVDR in reverse transcriptase (NRTI, NNRTI) Even when using protease inhibitors, HIVDR usually develops in reverse transcriptase backbone RT inhibitors: ABC, ddi, FTC, 3TC, d4t, TDF, AZT EFV, NVP PR inhibitors: only LPV, NFV, SQV, TPV IN inhibitors: none Entry inhibitors: none T-20, MVC

19 RT is most important target 97.1% adults ( ) and 96.8% children ( ) 1 st line 2.9% adults ( ) and 3.2% children (12.000) 2 nd line (LPV/r) 1 st line regimens in RLS 2 nd line regimens in RLS WHO Progress Report

20 Strategy #6: Generic Software

21 ARTA Field Evaluation Sites Uganda: JCRC sites South Africa: Wits University sites Zimbabwe: Newlands clinic (2012) Laboratory-based improvement of the protocol in UCMU, NL

22 Samples used in assay evaluation Site Uganda South Africa Plasma n=176 n=248 Viral loads copies/ml Subtypes A, D, 18_CPX C HIV-1 negative Paired DBS + Plasma 33 40

23 Viral Failure Assay (VFA) performance Virological Failure Uganda South Africa Assay Gold standard TaqMan (Roche) EasyQ (Biomerieux) Equipment MiniOpticon (Biorad) ABI 7900 (Applied biosystems) Linearirty (R 2 ) Intra-assay precision 0.41; 2.3% 0.40; 2.5% (SD ; %CV) Inter-assay precision 0.53; 1.8% 0.49 ;1.6% (SD ; %CV)) Accuracy (sensitivity/specificity) 100%; 92% 97%; 84% Inter-user reproducibility <0.5 log cp/ml differences No difference in virological failure determination <0.5 log cp/ml differences No difference in virological failure determination 22

24 HIVDR ultralight performance Table 4. Amplification and sequencing results of clinical samples tested at UMCU, The Netherlands VL Range (RNA copies/ml) n Subtypes* (n) A B C D AE AG Rare Amplification Success (%) Bidirectional Sequencing Success (%) > /35 (100%) 35/35 (100%) /45 (100%) 44/45 (97.8%) /89 (97.8%) 84/87 (96.6%) /43 (88.4%) 38/38 (100%) Total /212 (96.7%) 201/205 (98.1%) VL: Viral load; n: number of samples; * Indicated subtypes as assigned by both NCBI and GRADE. Table 5. Amplification results of clinical samples tested at JCRC, Uganda VL Range Subtypes* (n) Amplification n (RNA copies/ml) A AE D X Success (%) > /48 (100%) /36 (100%) /31 (100%) /17 (88.2%) Total /132 (98.5%) VL: Viral load; n: number of samples; * Indicated subtypes previously assigned; X: unassigned subtype, not previously sequenced. 23

25 Costing ARTA Assays In-house VL and HIVDR Costs US$/Sample TaqMan VL In-house HIVDR Total ART-A VL and HIVDR Costs US$/Sample ARTA VFA ARTA HIVDR ultralight Total Using the ARTA protocols cost saving $ *Excluding labour costs Based on costing studies South Africa,Wits University, Johannesburg 24

26 Capacity building Training lab staff Johannesburg Reference lab Esrom Letsoalo (VFA & HIVDR) Kampala Reference Laboratory Egau Isaac (VFA) Sheila Balinda (VFA & HIVDR) Leonard Bagenda (HIVDR) Mbale Regional Laboratory Iga Tadeo (VFA) Kigongo Frederick (VFA) Fortportal Regional Laboratory Mukembo Moses (VFA) Achidri Job (VFA) 25

27 ARTA field evaluation results + next steps Qualitative VF assay and HIVDR ultralight assay succesfully developed DBS collection and referral strategy are operational Good performance of the algorithm on subtypes A, C, D >50% cost reductions ARTA works on different real-time PCR instrument platforms ARTA technology successfully transferred to Uganda and South Africa Protection of IP through provisional patent RSA NACCAP-II grant for productizing (JCRC) 26

28 Acknowledgements PharmAccess Foundation Dept of Global Health AMC-UvA Amsterdam Institute for Global Health and Development Project support staff Raph Hamers Kim Sigaloff Corry Manting Desiree Lathouwer Tobias Rinke de Wit Aletta Kliphuis Nicole Spieker John Dekker PASER clinical sites Study teams Study participants JCRC, Uganda Project support staff Lab staff Cissy Kityo Peter Mugyenyi UMCU Virology, The Netherlands Rob Schuurman Sue Aitken University of the Witwatersrand, South Africa Lab staff Wendy Stevens Kim Steegen Michelle Bronze 27

29 ART-A consortium 28