title: Impact of primary elvitegravir resistance-associated mutations in HIV-1 integrase on drug susceptibility and viral replication fitness.
abstract: Elvitegravir (EVG) is an effective HIV-1 integrase (IN) strand transfer inhibitor (INSTI) in advanced clinical development. Primary INSTI resistance-associated mutations (RAMs) at six IN positions have been identified in HIV-1-infected patients failing EVG-containing regimens in clinical studies: T66I/A/K, E92Q/G, T97A, S147G, Q148R/H/K, and N155H. In this study, the effect of these primary IN mutations, alone and in combination, on susceptibility to the INSTIs EVG, raltegravir (RAL), and dolutegravir (DTG); IN enzyme activities; and viral replication fitness was characterized. Recombinant viruses containing the six most common mutations exhibited a range of reduced EVG susceptibility: 92-fold for Q148R, 30-fold for N155H, 26-fold for E92Q, 10-fold for T66I, 4-fold for S147G, and 2-fold for T97A. Less commonly observed primary IN mutations also showed a range of reduced EVG susceptibilities: 40- to 94-fold for T66K and Q148K and 5- to 10-fold for T66A, E92G, and Q148H. Some primary IN mutations exhibited broad cross-resistance between EVG and RAL (T66K, E92Q, Q148R/H/K, and N155H), while others retained susceptibility to RAL (T66I/A, E92G, T97A, and S147G). Dual combinations of primary IN mutations further reduced INSTI susceptibility, replication capacity, and viral fitness relative to either mutation alone. Susceptibility to DTG was retained by single primary IN mutations but reduced by dual mutation combinations with Q148R. Primary EVG RAMs also diminished IN enzymatic activities, concordant with their structural proximity to the active site. Greater reductions in viral fitness of dual mutation combinations may explain why some primary INSTI RAMs do not readily coexist on the same HIV-1 genome but rather establish independent pathways of resistance to EVG.
authors.affiliation: Gilead Sciences, Inc, Foster City, California, USA.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Abram
authors.forename: Rebecca M
authors.initials: RM
authors.lastname: Hluhanich
authors.forename: Derrick D
authors.initials: DD
authors.lastname: Goodman
authors.forename: Kristen N
authors.initials: KN
authors.lastname: Andreatta
authors.forename: Nicolas A
authors.initials: NA
authors.lastname: Margot
authors.forename: Linda
authors.initials: L
authors.lastname: Ye
authors.forename: Anita
authors.initials: A
authors.lastname: Niedziela-Majka
authors.forename: Tiffany L
authors.initials: TL
authors.lastname: Barnes
authors.forename: Nikolai
authors.initials: N
authors.lastname: Novikov
authors.forename: Xiaowu
authors.initials: X
authors.lastname: Chen
authors.forename: Evguenia S
authors.initials: ES
authors.lastname: Svarovskaia
authors.forename: Damian J
authors.initials: DJ
authors.lastname: McColl
authors.forename: Kirsten L
authors.initials: KL
authors.lastname: White
authors.forename: Michael D
authors.initials: MD
authors.lastname: Miller
mesh_terms: D002460:Cell Line; D024882:Drug Resistance, Viral / Q000235:genetics*; D005838:Genotype; D057809:HEK293 Cells; D015658:HIV Infections / Q000188:drug therapy / Q000821:virology; D019427:HIV Integrase / Q000235:genetics* / Q000378:metabolism; D015497:HIV-1 / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods; D009154:Mutation; D015363:Quinolones / Q000494:pharmacology*; D014779:Virus Replication / Q000187:drug effects / Q000235:genetics*
chemical_list: D015363:Quinolones; C509700:elvitegravir; D019427:HIV Integrase; C514801:p31 integrase protein, Human immunodeficiency virus 1