title: In vitro resistance development for RO-0335, a novel diphenylether nonnucleoside reverse transcriptase inhibitor.
abstract: Nonnucleoside reverse transcriptase inhibitors (NNRTIs) are important components of current combination therapies for the treatment of human immunodeficiency virus type 1 (HIV-1) infection. However, their low genetic barriers against resistance development, cross-resistance and serious side effects can compromise the benefits of the first generation compounds in this class (efavirenz and nevirapine). To study potential pathways leading to resistance against the novel diphenylether NNRTI, RO-0335, sequential passage experiments at low multiplicity of infection (MOI) were performed to solicit a stepwise selection of resistance mutations. Two pathways to loss of susceptibility to RO-0335 were observed, containing patterns of amino acid changes at either V106I/A plus F227C (with additional contributions from A98G, V108I, E138K, M230L and P236L) or V106I/Y188L (with a potential contribution from L100I, E138K and Y181C). Characterization of the observed mutations by site-directed mutagenesis in the isogenic HXB2D background demonstrated that a minimum of two or more mutations were required for significant loss of susceptibility, with the exception of Y188L, which requires a two-nucleotide change. Patterns containing F227C or quadruple mutations selected by RO-0335 showed a low relative fitness value when compared to wild-type HXB2D.
authors.affiliation: Virology Disease Biology Area, Roche Palo Alto, Palo Alto, CA 94304-1396, USA. hassan.javanbakht@roche.com
authors.forename: H
authors.initials: H
authors.lastname: Javanbakht
authors.forename: R G
authors.initials: RG
authors.lastname: Ptak
authors.forename: E
authors.initials: E
authors.lastname: Chow
authors.forename: J M
authors.initials: JM
authors.lastname: Yan
authors.forename: J D
authors.initials: JD
authors.lastname: Russell
authors.forename: M K
authors.initials: MK
authors.lastname: Mankowski
authors.forename: P A
authors.initials: PA
authors.lastname: Hogan
authors.forename: J H
authors.initials: JH
authors.lastname: Hogg
authors.forename: H
authors.initials: H
authors.lastname: Vora
authors.forename: J Q
authors.initials: JQ
authors.lastname: Hang
authors.forename: Y
authors.initials: Y
authors.lastname: Li
authors.forename: G
authors.initials: G
authors.lastname: Su
authors.forename: A
authors.initials: A
authors.lastname: Paul
authors.forename: N
authors.initials: N
authors.lastname: Cammack
authors.forename: K
authors.initials: K
authors.lastname: Klumpp
authors.forename: G
authors.initials: G
authors.lastname: Heilek
mesh_terms: D019943:Amino Acid Substitution / Q000235:genetics; D019380:Anti-HIV Agents / Q000737:chemistry / Q000494:pharmacology*; D002460:Cell Line; D004252:DNA Mutational Analysis; D024882:Drug Resistance, Viral; D054303:HIV Reverse Transcriptase / Q000037:antagonists & inhibitors*; D015497:HIV-1 / Q000187:drug effects*; D006801:Humans; D015394:Molecular Structure; D016297:Mutagenesis, Site-Directed; D020125:Mutation, Missense; D018894:Reverse Transcriptase Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D012692:Serial Passage
chemical_list: D019380:Anti-HIV Agents; D018894:Reverse Transcriptase Inhibitors; C514824:reverse transcriptase, Human immunodeficiency virus 1; D054303:HIV Reverse Transcriptase