What if a Drug that Was Developed to Treat HIV

Infection Could Actually Help to Cure It?

Mark A Wainberg McGill University AIDS Centre

Jewish General HospitalMontreal, Quebec, Canada

CONFIDENTIAL – NOT FOR DISSEMINATION

INI DISSOCIATION FROM WT IN-DNA COMPLEX AT 37°C

Adapted from Hightower KE, et al. Antimicrob Agents Chemother 2011;5:4552–9

INI koff

(s-1) t1/2

(h)

DTG 2.7 x 10-6 71

RAL 22 x 10-6 8.8

EVG 71 x 10-6 2.7

Koff , dissociation rate; t1/2h, half-life in hours

DTG dissociated more slowly from a WT IN-DNA complex at 37°C compared with RAL and EVG

DTG dissociation was eight times longer than RAL and 26 times slower than EVG

DTGRALEVG

1.0

0.8

0.6

0.4

0.2

0.0

Rela

tive

bind

ing

Time (h)

0 10 20 30 40 50 60

The R263K mutation decreases integrase activity in cell-free assays

B

0 5 10 15 20 250

5000

10000

15000

20000ININR263K

[Target DNA] (nM)

RFU

INR263K

0

5000

10000

15000

20000

RFU

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

The addition of H51Y to R263K further decreases IN strand transfer activity

A B

The combination of H51Y and R263K negatively impacts viral fitness

Virus Weeks 8-15  

WT M184VH51Y M184IR263K M184IH51Y/R263K NoneG118R NoneH51Y/G118R None

Selection of DTG-Resistant Viruses with 3TC

Replication Capacity of HIV Containing Various Combinations of INSTI Resistance Mutations

Mutation(s) % fitnessE92Q ≈ 75%Y143 ≈ 72%Q148 ≈ 75%N155 ≈ 75%R263K ≈ 70%G140/Q148 ≈ 95%R263K/H51Y ≈ 25%R263K/E138K ≈ 25%R263K/Q148R 0R263K/Y143C 0R263K/E92Q 0

Selection of HIV-1 containing R263K with RAL and EVG

Time(weeks)

Initial Mutation Acquired Mutations

EVG 30 R263K M50I, T66I

RAL 30 R263K ---

RAL 38 --- T97A/T, Y143H/Y, Q148K/Q

RAL 41 --- T97A, Y143R

No compensatory mutations in regard to DTG resistance and viral fitness have developed over more than three years in culture.

Hypotheses1. Viruses resistant to DTG via the R263K

pathway should not be transmissible because of low viral fitness

2. A series of judicious treatment interruptions followed by the use of DTG could conceivably convert viruses that are archived into attenuated forms. This subject should first be addressed in suitable animal models.

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

Acknowledgements

Thanks to CIHR and CANFAR