A sobering report of the first case of transmission of five-class resistance was presented by Walworth and colleagues from Monogram, from a patient treated in Washington, D.C.
The patient was hospitalised in 2010 during acute seroconversion and resistance testing showed mutations associated with reduced susceptibility to drugs from the classes of NRTIs, NNRTIs, protease inhibitors, fusion inhibitors and integrase inhibitors.
The mutation profile included L10Y, I13V, K20I, E35D, M36I, K43T, I62I/V, V82A in protease, M41L, D67N, L74V, V118I, K101E, Y181C, V189I, G190S in RT; G140S and Q148H in integrase and Q40R and N43S substitutions in gp41, with reduced drug susceptibility confirmed by phenotypic testing.
Based on resistance and tropism profiles, the patient was treated with a combination of tenofovir/FTC, darunavir/ritonavir and maraviroc. A good viral response was reported with viral suppression maintained at month 6.
The researchers commented that while this was the first case of five-class resistance, it included the third case of transmitted integrase resistance, and that including integrase in baseline testing would be increasingly important as this class becomes more widely used.
The patient achieved viral suppresion at week 12 using a combination of darunavir/ritonavir, tenofovir/FTC, and maraviroc.
Walworth C et al. Optimised antiretroviral drug selection achieves rapid and sustained suppression of viral replication, despite transmission of HIV-1 exhibiting resistance to five drug classes. 20th Intl Drug Resistance Workshop, 5-9 June 2012, Sitges. Abstract 92. Antiviral Therapy 2012: 17 Suppl 1:A112.
An earlier analysis of this case was also presented at the 19th IAS Conference. Abstract THPE063.
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