1385. High Tenofovir Failure Rates in an Emerging, Non-B Subtype HIV Epidemic
Session: Poster Abstract Session: HIV: Antiretroviral Therapy
Friday, October 6, 2017
Room: Poster Hall CD
Posters
  • Salvana TDF Poster 1385.pdf (521.7 kB)
  • Background:  The WHO-recommended regimen for antiretrovirals (ARVs) is tenofovir (TDF) + lamivudine/emtricitabine (3TC/FTC) + efavirenz (EFV), based on demonstrated superiority of TDF+FTC+EFV over zidovudine (AZT) +FTC+ EFV in clinical trials. However, there are reports of increasing TDF resistance in non-B subtypes. We have previously shown that HIV genotypes in the Philippines have shifted (https://idsa.confex.com/idsa/2014/webprogram/Paper45090.html) from B to CRF01_AE. We compared failure rates for ARVs during an acquired drug-resistance surveillance study.

    Methods: We analyzed ARV data from a study with the Department of Health on treatment failure in Filipinos after one year of treatment. Institutional Board Review approval and informed consent were obtained.

    Results:  513 adult patients from 3 national treatment hubs (Philippine General Hospital, San Lazaro Hospital, Vicente Sotto Memorial Medical Center) were enrolled and analyzed. Treatment failure (viral load>1000 copies/mL) at one year for specific regimens are summarized in Table 1. No baseline genotyping was available. 53 (10.3%) patients failed treatment. Genotypes among these were CRF01_AE (87%), B (11%) and C (2%). TDF-containing regimens had significantly higher failure rates (43/303;14.2%) than AZT-containing regimens (10/209;4.5%) (p< 0.001). Failure rates for NVP-based regimens (13/85;15.3%) versus EFV-based regimens (40/424; 9.4%) were not significantly different (p= 0.1064).

    The most durable regimen (with >3 patients) was AZT+3TC+EFV, and the worst regimen was TDF+3TC+NVP (p< 0.001). Failure rates for TDF+3TC+EFV were significantly higher than for AZT+3TC+EFV (p=0.0029). There was no significant difference in adherence (p=0.5531). 53% of unsuppressed patients had a TDF-resistance mutation, compared to 8% for AZT (p< 0.001).

    Conclusion: TDF-containing regimens were associated with higher treatment failure rates in our CRF01_AE-predominant HIV epidemic. WHO recommendations for treatment may need be revisited for non-B subtypes.

    Table 1. Failure rates for ARV regimens.

    Regimen

    On Regimen (N=513)

    Unsuppressed

    Failure

     (%)

    Adherence

     (%)

    TDF+3TC+EFV

    269

    34

    12.6

    66.5

    AZT+3TC+EFV

    155

    6

    3.9

    61.9

    TDF+3TC+NVP

    31

    9

    29.0

    64.5

    AZT+3TC+NVP

    54

    4

    7.4

    72.2

    TDF+3TC+LPV/r

    3

    0

    0

    33.3

    ABC+3TC+LPV/r

    1

    0

    0

    100

    Edsel Maurice Salvana, MD, DTM&H, FIDSA1,2,3, Brian Schwem, PhD1, Genesis Samonte, MD4, Elizabeth Telan, MD5, Rosario Tactacan-Abrenica, MD6, Patrick Ching, MD2, Kevin Mendoza, RN4, Geraldine Arevalo, BS1, Marissa Alejandria, MD, MSc7, Katerina Leyritana, MD2, Lyka Trinidad, RN4, Christine Penalosa, MD2 and Jodor Lim, MD, FPCP, FPSMID7, (1)Institute of Molecular Biology and Biotechnology, National Institutes of Health, University of the Philippines (UP-NIH), Manila, Philippines, (2)Department of Medicine, Section of Infectious Diseases, University of the Philippines - Philippine General Hospital, Manila, Philippines, (3)Philippine Genome Center, Quezon City, Philippines, (4)Epidemiology Bureau, Department of Health, Republic of the Philippines, Manila, Philippines, (5)STD and AIDS Cooperative Center Laboratory (SACCL), San Lazaro Hospital, Department of Health, Manila, Philippines, (6)San Lazaro Hospital, Department of Health, Manila, Philippines, (7)Section of Infectious Diseases, University of the Philippines-Philippine General Hospital, Manila, Philippines

    Disclosures:

    E. M. Salvana, Merck: Scientific Advisor and Speaker's Bureau , Consulting fee and Speaker honorarium

    B. Schwem, None

    G. Samonte, None

    E. Telan, None

    R. Tactacan-Abrenica, None

    P. Ching, None

    K. Mendoza, None

    G. Arevalo, None

    M. Alejandria, None

    K. Leyritana, None

    L. Trinidad, None

    C. Penalosa, None

    J. Lim, None

    Findings in the abstracts are embargoed until 12:01 a.m. PDT, Wednesday Oct. 4th with the exception of research findings presented at the IDWeek press conferences.