novel hiv suppressive approaches with integrase inhibitors

11

Novel HIV Suppressive Novel HIV Suppressive Approaches with Integrase Approaches with Integrase

InhibitorsInhibitors

Mark A WainbergMark A WainbergMcGill University AIDS CentreMcGill University AIDS Centre

Montreal, CanadaMontreal, Canada

Global distribution of HIV-1 subtypes

1.3 million1.3 million

4.8 million4.8 million

2 million2 million

B 10%B 10%A 12

%

A 12

%

URF 4.2%URF 4.2%

AG 6.7%

AG 6.7%

AE 3.1%AE 3.1%

G 5%G 5%

DD 3.6%3.6%

Rapid Selection of K65R Resistance in Subtype C Isolates

66

77

Previous work in our lab Previous work in our lab showed that MK-2048, a showed that MK-2048, a

Merck INSTI, selected G118R Merck INSTI, selected G118R followed by E138K. The latter followed by E138K. The latter

augmented levels of augmented levels of resistance against MK-2048 resistance against MK-2048 and also restored replicative and also restored replicative

fitness.fitness.

Major resistance pathways against INSTIs(clinical and tissue culture data)

Resistance pathwaysFold resistance

RAL EVG DTGY143 pathway      

Y143C <10 <2 <2Y143R <50 <2 <2

T97A/Y143C >100 <2 <2T97A/Y143R >100 <2 <2

L74M/T97A/Y143G <50 ND <2L74M/T97A/E138A/Y143C <20 ND <2

N155 pathway      N155H <50 <50 <2

E92Q/N155H <100 >100 <10L74M/N155H <50 <50 <2

Q148 pathway      Q148H <20 <10 <2Q148K <100 <100 <2Q148R <50 <100 <2

E138K/Q148H <10 <20 <2E138K/Q148K >100 >100 <20E138K/Q148R >100 >100 <10G140S/Q148H >100 >100 <20G140S/Q148K <10 <100 <2G140S/Q148R >100 >100 <10

E138A/G140S/Y143H/Q148H >100 ND <50Quashie et al., Curr. Opin. Infect. Diseases, in press

Secondary INSTI-resistance mutations often restore HIV replication capacity

Mbisa et al., Infect. and drug resistance, 2011--Canducci et al., JAC, 2010--Reigadas et al., Plos One, 2010--Delelis et al., AAC, 2009

Secondary Mutations (pathway)

Effect on viral fitness in the presence of primary resistance mutations

Y143 pathway - (often)

L74M, T97A +

N155H pathway -

Q95K, T97Q, G163R/K

+

Q148 pathway -

G140A/S/C, E138K/A

+

Dolutegravir activity on RAL-resistant clinical isolates

(n=39)(median IC50 for wild-type=1.07 nM)

GenotypeMedian fold

change

N155H 1.37

Y143R/T97A 1.05

Q148H/G140S 3.75

Q148R/G140S 13.3

Underwood et al., JAIDS, 2012

Resistance to INSTIs in clinical trials

in treatment-naïve patients

Treatment

Major resistance mutations detected by genotyping in treatment-naïve patients failing therapy

Minor resistance mutations

RaltegravirY143

N155HQ148

Multiple

Elvitegravir

T66IE92Q

N155HQ148

Multiple

Dolutegravir

NONE NONERALTEGRAVIRCooper et al., NEJM, 2008Sichtig et al, JAC, 2009Canducci et al, AIDS, 2009Hatano et al, JAIDS, 2010

ELVITEGRAVIRSax et al, Lancet, 2012DeJesus et al, Lancet, 2012

DOLUTEGRAVIRvanLunzen et al., Lancet Infect. Dis., 2012

Selection results with DTG

Quashie, et al, Journal of Virology 2012

Selection results with DTG

Quashie, et al, Journal of Virology 2012

Selection results with DTG

Quashie, et al, Journal of Virology 2012

Subtype-specific mutations selected in vitro with

dolutegravir

HIV-1 subtype

Most common mutations selected with

dolutegravir

B R263K, H51Y

C G118R, H51Y

Quashie, Mesplède et al., Journal of Virology, 2012

The R263K mutation confers low-level resistance to

dolutegravir in cell culture

Genotype IC50 fold change*

R263K 2.5 to 6

*Methodological differences(EC50 for wild-type ≈1-6nM) Quashie, Mesplède et al., Journal of Virology, 2012

The R263K mutation decreases integrase activity in cell-free

assays

Quashie, Mesplède et al., Journal of Virology, 2012

The R263K mutation decreases dolutegravir residency time

in an integrase-vDNA complex

The addition of H51Y to R263K further decreases IN strand

transfer activity

A B

The combination of H51Y and R263K negatively impacts viral

fitness

Effects of G118R and H51Y on in vitro strand transfer activity

IN protein

Relative strand transfer activity

(RFU/hr)Vmax ± SEM

WT 7,751.2 480.7H51Y 7,590.0 265.3G118R 6,138.5 621.5H51Y/G118R 3,223.0 130.2

Effects of H51Y, G118R and R263K mutations

on susceptibility to dolutegravir in cell culture

Genotype IC50 fold change*

R263K 2.5 to 6

H51Y 1 (no change)

H51Y/R263K 6 to 12

G118R 3 to 7

H51Y/G118R 6 to 10

*Methodological differences(EC50 for wild-type ≈1-6nM)

Dolutegravir resistance associates with

a decrease in viral replication capacity

Genotype ResistanceEffect on

viral fitness

R263K + -

H51Y None None

H51Y/R263K ++ - -

G118R + -

H51Y/G118R ++ - -

Conclusions• Resistance mutations selected in vitro with

dolutegravir are: R263K or G118R plus H51Y

• R263K and G118R confer low-level resistance against dolutegravir, e.g. 2.5-6 fold

• The addition of H51Y to either R263K or G118R increases resistance against DTG but also further decreases viral fitness

• These findings help to explain why resistance against dolutegravir in INSTI-naïve patients has not been observed

No compensatory mutations in regard to DTG resistance and viral fitness have developed over more than one year in culture. Might there be other implications for a drug that selects for an unfit virus and can animal models be of use?

• Bluma Brenner• Hongtao Xu• Dimitri Coutsinos• Jerry Zaharatos• Maureen Oliveira• Thibault Mesplède• Peter Quashie

Acknowledgements

MERCI