51. Intensification of a failing regimen with zidovudine may cause sustained virologic suppression in the presence of resensitising mutations including K65R
- Author
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Schlomo Staszewski, Annette Haberl, Brenda Dauer, L. Locher, Markus Bickel, Annemarie Berger, Hans Wilhelm Doerr, A. Müller, Martin Stürmer, S Klauke, and Christoph Stephan
- Subjects
Adult ,Male ,Microbiology (medical) ,Oncology ,medicine.medical_specialty ,Nevirapine ,Anti-HIV Agents ,Mutation, Missense ,HIV Infections ,Microbial Sensitivity Tests ,Zidovudine ,Abacavir ,Antiretroviral Therapy, Highly Active ,Internal medicine ,Drug Resistance, Viral ,medicine ,Humans ,Treatment Failure ,Didanosine ,Salvage Therapy ,Reverse-transcriptase inhibitor ,Nucleoside analogue ,business.industry ,virus diseases ,Lamivudine ,Middle Aged ,Viral Load ,Virology ,HIV Reverse Transcriptase ,Regimen ,Treatment Outcome ,Infectious Diseases ,Amino Acid Substitution ,HIV-1 ,Female ,business ,medicine.drug - Abstract
The reverse transcriptase (RT)-mutation K65R limits further therapeutic options and has been selected by unfavorable RT-combinations, e.g. tenofovir in combination with abacavir and/or didanosine.We identified HIV-1 infected patients from a large treatment cohort who experienced virological failure (HIV-1 RNA1000 copies/mL) with evidence of resistance mutations including the K65R, but without thymidine analogue mutations (TAMs) in genotypic resistance assay. Phenotype was performed from previously collected frozen plasma. The patients were followed for clinical and resistance outcome after treatment intensification with only zidovudine.Five patients had experienced antiretroviral treatment failure on various nucleoside analogue combinations, containing abacavir, didanosine, lamivudine, nevirapine, reverset and/or tenofovir. RT-sequence revealed mutations at position K65R in combination with other non-TAMs. The patients' median viral load prior to zidovudine intensification was 3.551 Log10 (range 3.053-4.681) and despite evidence for resistance to the failing drug regimen, all responded within 4 weeks to undetectable levels (1.699 Log10 or50 copies/mL) and remained virologically suppressed during follow-up (20 months through 6.5 years).In virologically failing patients due to K65R- and other non-thymidine-mutations, simple regimen intensification with zidovudine resulted in sustained HIV-1 suppression. The finding of re-sensitized HIV-1 in patients may be clinically relevant.
- Published
- 2010