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Zalenski N, Meredith BR, Savoie DJ, Naas MJ, Suo DJ, Betancourt D, Seay TW, Suo Z. Kinetic Investigation of Resistance to Islatravir Conferred by Mutations in HIV-1 Reverse Transcriptase. J Mol Biol 2025; 437:169100. [PMID: 40139311 DOI: 10.1016/j.jmb.2025.169100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2025] [Revised: 03/20/2025] [Accepted: 03/20/2025] [Indexed: 03/29/2025]
Abstract
Islatravir (EFdA) is a novel nucleoside reverse transcriptase translocation inhibitor (NRTTI) that potently blocks HIV-1 replication in vivo. Its unique structural features in contrast to nucleoside reverse transcriptase inhibitors (NRTIs), particularly the 4'-ethynyl and 3'-hydroxy groups, contribute to its high clinical potency. Once intracellularly activated to EFdA 5'-triphosphate (EFdA-TP), it competes with dATP for incorporation by HIV-1 reverse transcriptase (RT) during HIV-1 genomic replication. The 4'-ethynyl group of incorporated EFdA-MP interacts with a hydrophobic pocket of HIV-1 RT, hindering DNA translocation and terminating DNA synthesis. The M184V mutation, commonly associated with resistance to NRTIs such as lamivudine and emtricitabine, and the M184V/A114S mutations, both located within the hydrophobic pocket, were shown to reduce Islatravir susceptibility in cell-based viral resistance selection assays. To elucidate the mechanisms by which these mutations affect Islatravir inhibition, we employed pre-steady-state kinetics to investigate their impact on EFdA-TP incorporation by HIV-1 RT using both DNA and RNA templates. We found that M184V had a modest effect on EFdA-TP incorporation efficiency, increasing it 2-fold with the DNA template and decreasing it 3-fold with the RNA template. In contrast, M184V/A114S significantly inhibited EFdA-TP incorporation, reducing its incorporation efficiency 5.4-fold with the DNA template and 181-fold with the RNA template. These reductions were primarily attributable to corresponding decreases in EFdA-TP incorporation rate constants of 18-fold and 105-fold, respectively. These results suggest that, unlike FDA-approved NRTIs, the clinical efficacy of Islatravir, may not be substantially compromised by the M184V mutation alone but will be significantly reduced by the M184V/A114S mutations.
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Affiliation(s)
- Nikita Zalenski
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, FL 32306, USA
| | - Brianna R Meredith
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, FL 32306, USA
| | - Derek J Savoie
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, FL 32306, USA
| | - Mohamed J Naas
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, FL 32306, USA
| | - David J Suo
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, FL 32306, USA
| | - Daniel Betancourt
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, FL 32306, USA
| | - Turner W Seay
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, FL 32306, USA
| | - Zucai Suo
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, FL 32306, USA.
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Nka AD, Bouba Y, Tsapi Lontsi WR, Gouissi Anguechia DH, Teto G, Ka’e AC, Semengue ENJ, Ambe Chenwi C, Takou D, Forgwei L, Tekoh TAK, Ngueko AMK, Fokou BB, Efakika Gabisa J, Tchouaket MCT, TognaPabo WL, Ayuk Ngwese DT, Njiki Bikoi J, Armenia D, Colizzi V, Yotebieng M, Ndembi N, Santoro MM, Ceccherini-Silberstein F, Perno CF, Ndjolo A, Fokam J. Tenofovir and Doravirine Are Potential Reverse-Transcriptase Analogs in Combination with the New Reverse-Transcriptase Translocation Inhibitor (Islatravir) Among Treatment-Experienced Patients in Cameroon: Designing Future Treatment Strategies for Low- and Middle-Income Countries. Viruses 2025; 17:69. [PMID: 39861858 PMCID: PMC11768859 DOI: 10.3390/v17010069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2024] [Revised: 01/02/2025] [Accepted: 01/04/2025] [Indexed: 01/30/2025] Open
Abstract
Islatravir (ISL) is a novel antiretroviral that inhibits HIV-1 reverse transcriptase translocation. The M184V mutation, known to reduce ISL's viral susceptibility in vitro, could arise from prolonged exposure to nucleoside reverse transcriptase inhibitors (NRTI) (3TC). This study evaluated the predictive efficacy of ISL and identified potentially active antiretrovirals in combination among treatment-experienced patients in Cameroon, where NRTIs (3TC) have been the backbone of ART for decades now. Although ISL is a long-acting antiretroviral, it will provide other therapeutic options in combination with other reverse transcriptase inhibitors that remain effective. We analyzed 1170 HIV-1 sequences from patients failing first-, second-, and third-line ART using the CIRCB Antiviral Resistance Evaluation (CIRCB-CARE) database. Drug resistance mutations (DRMs) were interpreted using Stanford HIVdb.v9, and covariation patterns between M184V and major NRTI/NNRTI DRMs were assessed. The study population, with a median age of 40 years, showed a high prevalence of resistance to NRTIs (77.4%) and NNRTIs (49.2%). The most frequent NRTI DRMs were M184V/I (83.3%), M41L (25.0%), and T215FY (36.8%), while common NNRTI DRMs included K103NS (53.3%), Y181CIV (27.7%), and G190ASE (22.2%). In first-line ART failure, M184V significantly covaried with K70R, L74I, and M41L for NRTIs and K103N and G190A for NNRTIs. In second-line failure, the covariation with M184V extended to T215Y, M41L, and D67N for NRTIs and G190A, K103N, and K103S for NNRTIs. No significant covariation with M184V was observed in third-line treatment failures. Based on these covariations and on the effect of these mutations on available anti-HIV drugs, TDF (partial efficacy) and Doravirine (fully active) were identified as potentially suitable candidates in combination with ISL among patients failing the first, second, and third lines, and could serve as a valuable therapeutic option in LMICs facing similar treatment challenges.
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Affiliation(s)
- Alex Durand Nka
- Chantal BIYA International Reference Centre for Research on HIV/AIDS Prevention and Management, Yaoundé P.O. Box 3077, Cameroon; (Y.B.); (W.R.T.L.); (D.-H.G.A.); (G.T.); (A.c.K.); (E.N.J.S.); (C.A.C.); (D.T.); (L.F.); (T.A.-K.T.); (A.M.K.N.); (J.E.G.); (M.C.T.T.); (W.L.T.); (D.T.A.N.); (V.C.); (C.-F.P.); (A.N.)
| | - Yagai Bouba
- Chantal BIYA International Reference Centre for Research on HIV/AIDS Prevention and Management, Yaoundé P.O. Box 3077, Cameroon; (Y.B.); (W.R.T.L.); (D.-H.G.A.); (G.T.); (A.c.K.); (E.N.J.S.); (C.A.C.); (D.T.); (L.F.); (T.A.-K.T.); (A.M.K.N.); (J.E.G.); (M.C.T.T.); (W.L.T.); (D.T.A.N.); (V.C.); (C.-F.P.); (A.N.)
- Faculty of Medicine, UniCamillus-Saint Camillus International University of Health Sciences, 00131 Rome, Italy;
| | - Wilfried Rooker Tsapi Lontsi
- Chantal BIYA International Reference Centre for Research on HIV/AIDS Prevention and Management, Yaoundé P.O. Box 3077, Cameroon; (Y.B.); (W.R.T.L.); (D.-H.G.A.); (G.T.); (A.c.K.); (E.N.J.S.); (C.A.C.); (D.T.); (L.F.); (T.A.-K.T.); (A.M.K.N.); (J.E.G.); (M.C.T.T.); (W.L.T.); (D.T.A.N.); (V.C.); (C.-F.P.); (A.N.)
- Department of Microbiology, Faculty of Science, University of Yaoundé 1, Yaoundé P.O. Box 337, Cameroon;
| | - Davy-Hyacinte Gouissi Anguechia
- Chantal BIYA International Reference Centre for Research on HIV/AIDS Prevention and Management, Yaoundé P.O. Box 3077, Cameroon; (Y.B.); (W.R.T.L.); (D.-H.G.A.); (G.T.); (A.c.K.); (E.N.J.S.); (C.A.C.); (D.T.); (L.F.); (T.A.-K.T.); (A.M.K.N.); (J.E.G.); (M.C.T.T.); (W.L.T.); (D.T.A.N.); (V.C.); (C.-F.P.); (A.N.)
| | - Georges Teto
- Chantal BIYA International Reference Centre for Research on HIV/AIDS Prevention and Management, Yaoundé P.O. Box 3077, Cameroon; (Y.B.); (W.R.T.L.); (D.-H.G.A.); (G.T.); (A.c.K.); (E.N.J.S.); (C.A.C.); (D.T.); (L.F.); (T.A.-K.T.); (A.M.K.N.); (J.E.G.); (M.C.T.T.); (W.L.T.); (D.T.A.N.); (V.C.); (C.-F.P.); (A.N.)
| | - Aude christelle Ka’e
- Chantal BIYA International Reference Centre for Research on HIV/AIDS Prevention and Management, Yaoundé P.O. Box 3077, Cameroon; (Y.B.); (W.R.T.L.); (D.-H.G.A.); (G.T.); (A.c.K.); (E.N.J.S.); (C.A.C.); (D.T.); (L.F.); (T.A.-K.T.); (A.M.K.N.); (J.E.G.); (M.C.T.T.); (W.L.T.); (D.T.A.N.); (V.C.); (C.-F.P.); (A.N.)
| | - Ezechiel Ngoufack Jagni Semengue
- Chantal BIYA International Reference Centre for Research on HIV/AIDS Prevention and Management, Yaoundé P.O. Box 3077, Cameroon; (Y.B.); (W.R.T.L.); (D.-H.G.A.); (G.T.); (A.c.K.); (E.N.J.S.); (C.A.C.); (D.T.); (L.F.); (T.A.-K.T.); (A.M.K.N.); (J.E.G.); (M.C.T.T.); (W.L.T.); (D.T.A.N.); (V.C.); (C.-F.P.); (A.N.)
| | - Collins Ambe Chenwi
- Chantal BIYA International Reference Centre for Research on HIV/AIDS Prevention and Management, Yaoundé P.O. Box 3077, Cameroon; (Y.B.); (W.R.T.L.); (D.-H.G.A.); (G.T.); (A.c.K.); (E.N.J.S.); (C.A.C.); (D.T.); (L.F.); (T.A.-K.T.); (A.M.K.N.); (J.E.G.); (M.C.T.T.); (W.L.T.); (D.T.A.N.); (V.C.); (C.-F.P.); (A.N.)
- Department of Experimental Medicine, University of Rome Tor Vergata, 00133 Rome, Italy; (M.-M.S.); (F.C.-S.)
| | - Désiré Takou
- Chantal BIYA International Reference Centre for Research on HIV/AIDS Prevention and Management, Yaoundé P.O. Box 3077, Cameroon; (Y.B.); (W.R.T.L.); (D.-H.G.A.); (G.T.); (A.c.K.); (E.N.J.S.); (C.A.C.); (D.T.); (L.F.); (T.A.-K.T.); (A.M.K.N.); (J.E.G.); (M.C.T.T.); (W.L.T.); (D.T.A.N.); (V.C.); (C.-F.P.); (A.N.)
| | - Lum Forgwei
- Chantal BIYA International Reference Centre for Research on HIV/AIDS Prevention and Management, Yaoundé P.O. Box 3077, Cameroon; (Y.B.); (W.R.T.L.); (D.-H.G.A.); (G.T.); (A.c.K.); (E.N.J.S.); (C.A.C.); (D.T.); (L.F.); (T.A.-K.T.); (A.M.K.N.); (J.E.G.); (M.C.T.T.); (W.L.T.); (D.T.A.N.); (V.C.); (C.-F.P.); (A.N.)
| | - Tatiana Anim-Keng Tekoh
- Chantal BIYA International Reference Centre for Research on HIV/AIDS Prevention and Management, Yaoundé P.O. Box 3077, Cameroon; (Y.B.); (W.R.T.L.); (D.-H.G.A.); (G.T.); (A.c.K.); (E.N.J.S.); (C.A.C.); (D.T.); (L.F.); (T.A.-K.T.); (A.M.K.N.); (J.E.G.); (M.C.T.T.); (W.L.T.); (D.T.A.N.); (V.C.); (C.-F.P.); (A.N.)
| | - Aurelie Minelle Kengni Ngueko
- Chantal BIYA International Reference Centre for Research on HIV/AIDS Prevention and Management, Yaoundé P.O. Box 3077, Cameroon; (Y.B.); (W.R.T.L.); (D.-H.G.A.); (G.T.); (A.c.K.); (E.N.J.S.); (C.A.C.); (D.T.); (L.F.); (T.A.-K.T.); (A.M.K.N.); (J.E.G.); (M.C.T.T.); (W.L.T.); (D.T.A.N.); (V.C.); (C.-F.P.); (A.N.)
| | - Bernadette Bomgning Fokou
- Department of Immunology, Molecular Medicine and Applied Biotechnology, University of Rome Tor Vergata, 00133 Rome, Italy;
| | - Jeremiah Efakika Gabisa
- Chantal BIYA International Reference Centre for Research on HIV/AIDS Prevention and Management, Yaoundé P.O. Box 3077, Cameroon; (Y.B.); (W.R.T.L.); (D.-H.G.A.); (G.T.); (A.c.K.); (E.N.J.S.); (C.A.C.); (D.T.); (L.F.); (T.A.-K.T.); (A.M.K.N.); (J.E.G.); (M.C.T.T.); (W.L.T.); (D.T.A.N.); (V.C.); (C.-F.P.); (A.N.)
| | - Michel Carlos Tommo Tchouaket
- Chantal BIYA International Reference Centre for Research on HIV/AIDS Prevention and Management, Yaoundé P.O. Box 3077, Cameroon; (Y.B.); (W.R.T.L.); (D.-H.G.A.); (G.T.); (A.c.K.); (E.N.J.S.); (C.A.C.); (D.T.); (L.F.); (T.A.-K.T.); (A.M.K.N.); (J.E.G.); (M.C.T.T.); (W.L.T.); (D.T.A.N.); (V.C.); (C.-F.P.); (A.N.)
| | - Willy Leroi TognaPabo
- Chantal BIYA International Reference Centre for Research on HIV/AIDS Prevention and Management, Yaoundé P.O. Box 3077, Cameroon; (Y.B.); (W.R.T.L.); (D.-H.G.A.); (G.T.); (A.c.K.); (E.N.J.S.); (C.A.C.); (D.T.); (L.F.); (T.A.-K.T.); (A.M.K.N.); (J.E.G.); (M.C.T.T.); (W.L.T.); (D.T.A.N.); (V.C.); (C.-F.P.); (A.N.)
| | - Derrick Tambe Ayuk Ngwese
- Chantal BIYA International Reference Centre for Research on HIV/AIDS Prevention and Management, Yaoundé P.O. Box 3077, Cameroon; (Y.B.); (W.R.T.L.); (D.-H.G.A.); (G.T.); (A.c.K.); (E.N.J.S.); (C.A.C.); (D.T.); (L.F.); (T.A.-K.T.); (A.M.K.N.); (J.E.G.); (M.C.T.T.); (W.L.T.); (D.T.A.N.); (V.C.); (C.-F.P.); (A.N.)
| | - Jacky Njiki Bikoi
- Department of Microbiology, Faculty of Science, University of Yaoundé 1, Yaoundé P.O. Box 337, Cameroon;
| | - Daniele Armenia
- Faculty of Medicine, UniCamillus-Saint Camillus International University of Health Sciences, 00131 Rome, Italy;
| | - Vittorio Colizzi
- Chantal BIYA International Reference Centre for Research on HIV/AIDS Prevention and Management, Yaoundé P.O. Box 3077, Cameroon; (Y.B.); (W.R.T.L.); (D.-H.G.A.); (G.T.); (A.c.K.); (E.N.J.S.); (C.A.C.); (D.T.); (L.F.); (T.A.-K.T.); (A.M.K.N.); (J.E.G.); (M.C.T.T.); (W.L.T.); (D.T.A.N.); (V.C.); (C.-F.P.); (A.N.)
| | - Marcel Yotebieng
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA;
| | - Nicaise Ndembi
- Africa Centres for Disease Control and Prevention, Addis Ababa P.O. Box 3243, Ethiopia;
| | - Maria-Mercedes Santoro
- Department of Experimental Medicine, University of Rome Tor Vergata, 00133 Rome, Italy; (M.-M.S.); (F.C.-S.)
| | | | - Carlo-Federico Perno
- Chantal BIYA International Reference Centre for Research on HIV/AIDS Prevention and Management, Yaoundé P.O. Box 3077, Cameroon; (Y.B.); (W.R.T.L.); (D.-H.G.A.); (G.T.); (A.c.K.); (E.N.J.S.); (C.A.C.); (D.T.); (L.F.); (T.A.-K.T.); (A.M.K.N.); (J.E.G.); (M.C.T.T.); (W.L.T.); (D.T.A.N.); (V.C.); (C.-F.P.); (A.N.)
- Microbiology and Diagnostic Immunology Unit, Bambino Gesù Children’s Hospital, IRCCS, 00165 Rome, Italy
| | - Alexis Ndjolo
- Chantal BIYA International Reference Centre for Research on HIV/AIDS Prevention and Management, Yaoundé P.O. Box 3077, Cameroon; (Y.B.); (W.R.T.L.); (D.-H.G.A.); (G.T.); (A.c.K.); (E.N.J.S.); (C.A.C.); (D.T.); (L.F.); (T.A.-K.T.); (A.M.K.N.); (J.E.G.); (M.C.T.T.); (W.L.T.); (D.T.A.N.); (V.C.); (C.-F.P.); (A.N.)
| | - Joseph Fokam
- Chantal BIYA International Reference Centre for Research on HIV/AIDS Prevention and Management, Yaoundé P.O. Box 3077, Cameroon; (Y.B.); (W.R.T.L.); (D.-H.G.A.); (G.T.); (A.c.K.); (E.N.J.S.); (C.A.C.); (D.T.); (L.F.); (T.A.-K.T.); (A.M.K.N.); (J.E.G.); (M.C.T.T.); (W.L.T.); (D.T.A.N.); (V.C.); (C.-F.P.); (A.N.)
- Central Technical Group, National AIDS Control Committee, Yaoundé P.O. Box 1459, Cameroon
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Williams V, Cory TJ. Doravirine/islatravir for the treatment of HIV. Expert Opin Pharmacother 2025; 26:9-15. [PMID: 39651697 DOI: 10.1080/14656566.2024.2440000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2024] [Accepted: 12/05/2024] [Indexed: 12/11/2024]
Abstract
INTRODUCTION HIV is a global disease affecting millions of people. While treatments have improved over the past decades, treatment failure remains a significant issue for treatment experienced patients. Doravirine/islatravir is a new dual-therapy regimen with a promising resistance profile and reductions in central nervous system effects. Recent trials have shown non-inferiority compared to current standards of care. However, current research suggests that CD4 counts decrease in an islatravir-dose dependent manner, but more data is needed to determine the full extent of this effect at lower doses. AREAS COVERED Doravirine/islatravir is a therapeutic combination for the treatment of HIV which is currently in Phase 3 trials. This article reviews key studies regarding the safety and efficacy of the combination. EXPERT OPINION When approved, doravirine/islatravir should be considered for patients who have previously failed treatment due to viral resistance. It expands the selection of two-drug single-pill therapies and introduces a novel mechanism of action to the market. However, more data is needed regarding the effects of islatravir on CD4 counts. ISL doses as low as 0.25 mg proved non-inferior to current treatments. Therefore, evaluation of the long-term efficacy and safety of DOR/ISL should focus on reduced doses of ISL and minimizing CD4 reduction.
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Affiliation(s)
- Valerie Williams
- Department of Clinical Pharmacy and Translational Science, University of Tennessee Health Science Center College of Pharmacy, Memphis, TN, USA
| | - Theodore James Cory
- Department of Clinical Pharmacy and Translational Science, University of Tennessee Health Science Center College of Pharmacy, Memphis, TN, USA
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Byun H, Papathanasopoulos MA, Steegen K, Basson AE. Thymidine Analogue Mutations with M184V Significantly Decrease Phenotypic Susceptibility of HIV-1 Subtype C Reverse Transcriptase to Islatravir. Viruses 2024; 16:1888. [PMID: 39772195 PMCID: PMC11680407 DOI: 10.3390/v16121888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2024] [Revised: 11/29/2024] [Accepted: 12/03/2024] [Indexed: 01/30/2025] Open
Abstract
Islatravir (ISL) is the first-in-class nucleoside reverse transcriptase translocation inhibitor (NRTtI) with novel modes of action. Data on ISL resistance are currently limited, particularly to HIV-1 non-B subtypes. This study aimed to assess prevalent nucleos(t)ide reverse transcriptase inhibitor (NRTI)-resistant mutations in HIV-1 subtype C for their phenotypic resistance to ISL. Prevalent single and combinations of NRTI-resistant mutations were selected from a routine HIV-1 genotypic drug resistance testing database and introduced into HIV-1 subtype C-like pseudoviruses, which were then tested for ISL susceptibility. Single NRTI-resistant mutations were susceptible or showed only a low level of resistance to ISL. This included thymidine analogue mutations (TAMs, i.e., M41L, D67N, K70R, T215FY, and K219EQ) and non-TAMs (i.e., A62V, K65R, K70ET, L74IV, A114S, Y115F, and M184V). Combinations of M184V with one or more additional NRTI-resistant mutations generally displayed reduced ISL susceptibilities. This was more prominent for combinations that included M184V+TAMs, and particularly M184V+TAM-2 mutations. Combinations that included M184V+K65R did not impact significantly on ISL susceptibility. Our study suggests that ISL would be effective in treating people living with HIV (PLWH) failing tenofovir disoproxil fumarate (TDF)/lamivudine (3TC) or TDF/emtricitabine (FTC)-containing regimens, but would be less effective in PLH failing zidovudine (AZT) with 3TC or FTC-containing regimens.
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Affiliation(s)
- Hyeonah Byun
- HIV Pathogenesis Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa; (H.B.); (M.A.P.)
| | - Maria Antonia Papathanasopoulos
- HIV Pathogenesis Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa; (H.B.); (M.A.P.)
| | - Kim Steegen
- National Priority Programme, National Health Laboratory Service, Johannesburg 2192, South Africa;
- Department of Molecular Medicine and Haematology, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa
| | - Adriaan Erasmus Basson
- HIV Pathogenesis Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa; (H.B.); (M.A.P.)
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Li Y, Choudhary M, Mellors JW. The Current Pipeline of Antiretroviral Therapy: Expanding Options and Filling Gaps. Infect Dis Clin North Am 2024; 38:395-408. [PMID: 38876905 DOI: 10.1016/j.idc.2024.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2024]
Abstract
Highly effective antiretroviral therapy (ART) has transformed human immunodeficiency virus (HIV) care in the past 3 decades. 30 years ago, how many would have imagined that a single-tablet daily ART regimen containing different drug classes could achieve sustained HIV-1 suppression and halt disease progression to acquired immunodeficiency syndrome (AIDS)? Despite this remarkable achievement, challenges in HIV care remain that require further innovation for ART. In this review, we focus on newly approved antiretroviral agents and those undergoing phase 2/3 clinical trials. These new antiretrovirals hold great promise to expand treatment options and fill gaps in HIV care.
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Affiliation(s)
- Yijia Li
- Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Madhu Choudhary
- Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - John W Mellors
- Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
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Diamond TL, Goh SL, Ngo W, Rodriguez S, Xu M, Klein DJ, Grobler JA, Asante-Appiah E. No antagonism or cross-resistance and a high barrier to the emergence of resistance in vitro for the combination of islatravir and lenacapavir. Antimicrob Agents Chemother 2024; 68:e0033424. [PMID: 38864613 PMCID: PMC11232396 DOI: 10.1128/aac.00334-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Accepted: 05/10/2024] [Indexed: 06/13/2024] Open
Abstract
Islatravir (ISL) is a deoxyadenosine analog that inhibits HIV-1 reverse transcription by multiple mechanisms. Lenacapavir (LEN) is a novel capsid inhibitor that inhibits HIV-1 at multiple stages throughout the viral life cycle. ISL and LEN are being investigated as once-weekly combination oral therapy for the treatment of HIV-1. Here, we characterized ISL and LEN in vitro to assess combinatorial antiviral activity, cytotoxicity, and the potential for interactions between the two compounds. Bliss analysis revealed ISL with LEN demonstrated additive inhibition of HIV-1 replication, with no evidence of antagonism across the range of concentrations tested. ISL exhibited potent antiviral activity against variants encoding known LEN resistance-associated mutations (RAMs) with or without the presence of M184V, an ISL RAM in reverse transcriptase (RT) . Static resistance selection experiments were conducted with ISL and LEN alone and in combination, initiating with either wild-type virus or virus containing the M184I RAM in RT to further assess their barrier to the emergence of resistance. The combination of ISL with LEN more effectively suppressed viral breakthrough at lower multiples of the compounds' IC50 (half-maximal inhibitory concentration) values and fewer mutations emerged with the combination compared to either compound on its own. The known pathways for development of resistance with ISL and LEN were not altered, and no novel single mutations emerged that substantially reduced susceptibility to either compound. The lack of antagonism and cross-resistance between ISL and LEN support the ongoing evaluation of the combination for treatment of HIV-1.
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Affiliation(s)
| | | | - Winnie Ngo
- Merck & Co., Inc., Rahway, New Jersey, USA
| | | | - Min Xu
- Merck & Co., Inc., Rahway, New Jersey, USA
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Hikichi Y, Grover JR, Schäfer A, Mothes W, Freed EO. Epistatic pathways can drive HIV-1 escape from integrase strand transfer inhibitors. SCIENCE ADVANCES 2024; 10:eadn0042. [PMID: 38427738 PMCID: PMC10906922 DOI: 10.1126/sciadv.adn0042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 01/26/2024] [Indexed: 03/03/2024]
Abstract
People living with human immunodeficiency virus (HIV) receiving integrase strand transfer inhibitors (INSTIs) have been reported to experience virological failure in the absence of resistance mutations in integrase. To elucidate INSTI resistance mechanisms, we propagated HIV-1 in the presence of escalating concentrations of the INSTI dolutegravir. HIV-1 became resistant to dolutegravir by sequentially acquiring mutations in the envelope glycoprotein (Env) and the nucleocapsid protein. The selected Env mutations enhance the ability of the virus to spread via cell-cell transfer, thereby increasing the multiplicity of infection (MOI). While the selected Env mutations confer broad resistance to multiple classes of antiretrovirals, the fold resistance is ~2 logs higher for INSTIs than for other classes of drugs. We demonstrate that INSTIs are more readily overwhelmed by high MOI than other classes of antiretrovirals. Our findings advance the understanding of how HIV-1 can evolve resistance to antiretrovirals, including the potent INSTIs, in the absence of drug-target gene mutations.
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Affiliation(s)
- Yuta Hikichi
- Virus-Cell Interaction Section, HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, Frederick, MD, USA
| | - Jonathan R. Grover
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, USA
| | - Alicia Schäfer
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, USA
| | - Walther Mothes
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT, USA
| | - Eric O. Freed
- Virus-Cell Interaction Section, HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, Frederick, MD, USA
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8
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Pons-Faudoa FP, Di Trani N, Capuani S, Facchi I, Wood AM, Nehete B, DeLise A, Sharma S, Shelton KA, Bushman LR, Chua CYX, Ittmann MM, Kimata JT, Anderson PL, Nehete PN, Arduino RC, Grattoni A. Antiviral potency of long-acting islatravir subdermal implant in SHIV-infected macaques. J Control Release 2024; 366:18-27. [PMID: 38142963 PMCID: PMC10922355 DOI: 10.1016/j.jconrel.2023.12.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 11/14/2023] [Accepted: 12/18/2023] [Indexed: 12/26/2023]
Abstract
Treatment nonadherence is a pressing issue in people living with HIV (PLWH), as they require lifelong therapy to maintain viral suppression. Poor adherence leads to antiretroviral (ARV) resistance, transmission to others, AIDS progression, and increased morbidity and mortality. Long-acting (LA) ARV therapy is a promising strategy to combat the clinical drawback of user-dependent dosing. Islatravir (ISL) is a promising candidate for HIV treatment given its long half-life and high potency. Here we show constant ISL release from a subdermal LA nanofluidic implant achieves viral load reduction in SHIV-infected macaques. Specifically, a mean delivery dosage of 0.21 ± 0.07 mg/kg/day yielded a mean viral load reduction of -2.30 ± 0.53 log10 copies/mL at week 2, compared to baseline. The antiviral potency of the ISL delivered from the nanofluidic implant was higher than oral ISL dosed either daily or weekly. At week 3, viral resistance to ISL emerged in 2 out of 8 macaques, attributable to M184V mutation, supporting the need of combining ISL with other ARV for HIV treatment. The ISL implant produced moderate reactivity in the surrounding tissue, indicating tolerability. Overall, we present the ISL subdermal implant as a promising approach for LA ARV treatment in PLWH.
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Affiliation(s)
- Fernanda P Pons-Faudoa
- Department of Nanomedicine, Houston Methodist Research Institute, Houston, TX 77030, USA
| | - Nicola Di Trani
- Department of Nanomedicine, Houston Methodist Research Institute, Houston, TX 77030, USA
| | - Simone Capuani
- Department of Nanomedicine, Houston Methodist Research Institute, Houston, TX 77030, USA
| | - Ilaria Facchi
- Department of Nanomedicine, Houston Methodist Research Institute, Houston, TX 77030, USA
| | - Anthony M Wood
- Department of Nanomedicine, Houston Methodist Research Institute, Houston, TX 77030, USA
| | - Bharti Nehete
- Department of Comparative Medicine, Michael E. Keeling Center for Comparative Medicine and Research, MD Anderson Cancer Center, Bastrop, TX 78602, USA
| | - Ashley DeLise
- Department of Comparative Medicine, Michael E. Keeling Center for Comparative Medicine and Research, MD Anderson Cancer Center, Bastrop, TX 78602, USA
| | - Suman Sharma
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Kathryn A Shelton
- Department of Comparative Medicine, Michael E. Keeling Center for Comparative Medicine and Research, MD Anderson Cancer Center, Bastrop, TX 78602, USA
| | - Lane R Bushman
- Deparment of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado- Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Corrine Ying Xuan Chua
- Department of Nanomedicine, Houston Methodist Research Institute, Houston, TX 77030, USA
| | - Michael M Ittmann
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jason T Kimata
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Peter L Anderson
- Deparment of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado- Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Pramod N Nehete
- Department of Comparative Medicine, Michael E. Keeling Center for Comparative Medicine and Research, MD Anderson Cancer Center, Bastrop, TX 78602, USA; The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX 77030, USA
| | - Roberto C Arduino
- Division of Infectious Diseases, Department of Internal Medicine, McGovern Medical School at The University of Texas Health Science Center, Houston, TX 77030, USA
| | - Alessandro Grattoni
- Department of Nanomedicine, Houston Methodist Research Institute, Houston, TX 77030, USA; Department of Surgery, Houston Methodist Research Institute, Houston, TX 77030, USA; Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX 77030, USA.
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9
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Cilento ME, Wen X, Reeve AB, Ukah OB, Snyder AA, Carrillo CM, Smith CP, Edwards K, Wahoski CC, Kitzler DR, Kodama EN, Mitsuya H, Parniak MA, Tedbury PR, Sarafianos SG. HIV-1 Resistance to Islatravir/Tenofovir Combination Therapy in Wild-Type or NRTI-Resistant Strains of Diverse HIV-1 Subtypes. Viruses 2023; 15:1990. [PMID: 37896768 PMCID: PMC10612037 DOI: 10.3390/v15101990] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 09/15/2023] [Accepted: 09/18/2023] [Indexed: 10/29/2023] Open
Abstract
Tenofovir disoproxil fumarate (TDF) and islatravir (ISL, 4'-ethynyl-2-fluoro-2'-deoxyadensine, or MK-8591) are highly potent nucleoside reverse transcriptase inhibitors. Resistance to TDF and ISL is conferred by K65R and M184V, respectively. Furthermore, K65R and M184V increase sensitivity to ISL and TDF, respectively. Therefore, these two nucleoside analogs have opposing resistance profiles and could present a high genetic barrier to resistance. To explore resistance to TDF and ISL in combination, we performed passaging experiments with HIV-1 WT, K65R, or M184V in the presence of ISL and TDF. We identified K65R, M184V, and S68G/N mutations. The mutant most resistant to ISL was S68N/M184V, yet it remained susceptible to TDF. To further confirm our cellular findings, we implemented an endogenous reverse transcriptase assay to verify in vitro potency. To better understand the impact of these resistance mutations in the context of global infection, we determined potency of ISL and TDF against HIV subtypes A, B, C, D, and circulating recombinant forms (CRF) 01_AE and 02_AG with and without resistance mutations. In all isolates studied, we found K65R imparted hypersensitivity to ISL whereas M184V conferred resistance. We demonstrated that the S68G polymorphism can enhance fitness of drug-resistant mutants in some genetic backgrounds. Collectively, the data suggest that the opposing resistance profiles of ISL and TDF suggest that a combination of the two drugs could be a promising drug regimen for the treatment of patients infected with any HIV-1 subtype, including those who have failed 3TC/FTC-based therapies.
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Affiliation(s)
- Maria E. Cilento
- Center for ViroScience and Cure, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Xin Wen
- Center for ViroScience and Cure, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Aaron B. Reeve
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Obiaara B. Ukah
- CS Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
| | - Alexa A. Snyder
- Center for ViroScience and Cure, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Ciro M. Carrillo
- Center for ViroScience and Cure, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Cole P. Smith
- Center for ViroScience and Cure, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Kristin Edwards
- Center for ViroScience and Cure, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Claudia C. Wahoski
- Center for ViroScience and Cure, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Deborah R. Kitzler
- Center for ViroScience and Cure, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Eiichi N. Kodama
- Division of Infectious Disease, International Institute of Disaster Science, Tohoku University, Sendai 980-8572, Japan
| | - Hiroaki Mitsuya
- Department of Refractory Viral Infections, National Center for Global Health & Medicine Research Institute, Tokyo 162-8655, Japan
- Experimental Retrovirology Section, HIV and AIDS Malignancy Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
- Department of Clinical Sciences, Kumamoto University Hospital, Kumamoto 860-8556, Japan
| | - Michael A. Parniak
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Philip R. Tedbury
- Center for ViroScience and Cure, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Stefan G. Sarafianos
- Center for ViroScience and Cure, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
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10
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HIV and Drug-Resistant Subtypes. Microorganisms 2023; 11:microorganisms11010221. [PMID: 36677513 PMCID: PMC9861097 DOI: 10.3390/microorganisms11010221] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 01/03/2023] [Accepted: 01/13/2023] [Indexed: 01/18/2023] Open
Abstract
Acquired Immunodeficiency Syndrome (AIDS) is a human viral infectious disease caused by the positive-sense single-stranded (ss) RNA Human Immunodeficiency Virus (HIV) (Retroviridae family, Ortervirales order). HIV-1 can be distinguished into various worldwide spread groups and subtypes. HIV-2 also causes human immunodeficiency, which develops slowly and tends to be less aggressive. HIV-2 only partially homologates to HIV-1 despite the similar derivation. Antiretroviral therapy (ART) is the treatment approved to control HIV infection, based on multiple antiretroviral drugs that belong to different classes: (i) NNRTIs, (ii) NRTIs, (iii) PIs, (iv) INSTIs, and (v) entry inhibitors. These drugs, acting on different stages of the HIV life cycle, decrease the patient's total burden of HIV, maintain the function of the immune system, and prevent opportunistic infections. The appearance of several strains resistant to these drugs, however, represents a problem today that needs to be addressed as best as we can. New outbreaks of strains show a widespread geographic distribution and a highly variable mortality rate, even affecting treated patients significantly. Therefore, novel treatment approaches should be explored. The present review discusses updated information on HIV-1- and HIV-2-resistant strains, including details on different mutations responsible for drug resistance.
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11
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Amblard F, Patel D, Michailidis E, Coats SJ, Kasthuri M, Biteau N, Tber Z, Ehteshami M, Schinazi RF. HIV nucleoside reverse transcriptase inhibitors. Eur J Med Chem 2022; 240:114554. [PMID: 35792384 DOI: 10.1016/j.ejmech.2022.114554] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 06/15/2022] [Accepted: 06/16/2022] [Indexed: 11/28/2022]
Abstract
More than 40 years into the pandemic, HIV remains a global burden and as of now, there is no cure in sight. Fortunately, highly active antiretroviral therapy (HAART) has been developed to manage and suppress HIV infection. Combinations of two to three drugs targeting key viral proteins, including compounds inhibiting HIV reverse transcriptase (RT), have become the cornerstone of HIV treatment. This review discusses nucleoside reverse transcriptase inhibitors (NRTIs), including chain terminators, delayed chain terminators, nucleoside reverse transcriptase translocation inhibitors (NRTTIs), and nucleotide competing RT inhibitors (NcRTIs); focusing on their history, mechanism of action, resistance, and current clinical application, including long-acting regimens.
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Affiliation(s)
- Franck Amblard
- Center for ViroScience and Cure, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, and Children's Healthcare of Atlanta, 1760 Haygood Drive, Atlanta, GA, 30322, USA
| | - Dharmeshkumar Patel
- Center for ViroScience and Cure, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, and Children's Healthcare of Atlanta, 1760 Haygood Drive, Atlanta, GA, 30322, USA
| | - Eleftherios Michailidis
- Center for ViroScience and Cure, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, and Children's Healthcare of Atlanta, 1760 Haygood Drive, Atlanta, GA, 30322, USA
| | - Steven J Coats
- Center for ViroScience and Cure, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, and Children's Healthcare of Atlanta, 1760 Haygood Drive, Atlanta, GA, 30322, USA
| | - Mahesh Kasthuri
- Center for ViroScience and Cure, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, and Children's Healthcare of Atlanta, 1760 Haygood Drive, Atlanta, GA, 30322, USA
| | - Nicolas Biteau
- Center for ViroScience and Cure, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, and Children's Healthcare of Atlanta, 1760 Haygood Drive, Atlanta, GA, 30322, USA
| | - Zahira Tber
- Center for ViroScience and Cure, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, and Children's Healthcare of Atlanta, 1760 Haygood Drive, Atlanta, GA, 30322, USA
| | - Maryam Ehteshami
- Center for ViroScience and Cure, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, and Children's Healthcare of Atlanta, 1760 Haygood Drive, Atlanta, GA, 30322, USA
| | - Raymond F Schinazi
- Center for ViroScience and Cure, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, and Children's Healthcare of Atlanta, 1760 Haygood Drive, Atlanta, GA, 30322, USA.
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Parikh UM, Mellors JW. How could HIV-1 drug resistance impact preexposure prophylaxis for HIV prevention? Curr Opin HIV AIDS 2022; 17:213-221. [PMID: 35762376 PMCID: PMC9245149 DOI: 10.1097/coh.0000000000000746] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE OF REVIEW To review current laboratory and clinical data on the frequency and relative risk of drug resistance and range of mutations selected from approved and investigational antiretroviral agents used for preexposure prophylaxis (PrEP) of HIV-1 infection, including tenofovir disproxil fumarate (TDF)-based oral PrEP, dapivirine ring, injectable cabotegravir (CAB), islatravir, lenacapavir and broadly neutralizing antibodies (bNAbs). RECENT FINDINGS The greatest risk of HIV-1 resistance from PrEP with oral TDF/emtricitabine (FTC) or injectable CAB is from starting or continuing PrEP after undiagnosed acute HIV infection. By contrast, the dapivirine intravaginal ring does not appear to select nonnucleoside reverse transcriptase inhibitor resistance in clinical trial settings. Investigational inhibitors including islatravir, lenacapavir, and bNAbs are promising for use as PrEP due to their potential for sustained delivery and low risk of cross-resistance to currently used antiretrovirals, but surveillance for emergence of resistance mutations in more HIV-1 gene regions (gag, env) will be important as the same drugs are being developed for HIV therapy. SUMMARY PrEP is highly effective in preventing HIV infection. Although HIV drug resistance from PrEP use could impact future options in individuals who seroconvert on PrEP, the current risk is low and continued monitoring for the emergence of resistance and cross-resistance during product development, clinical studies, and product roll-out is advised to preserve antiretroviral efficacy for both treatment and prevention.
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Affiliation(s)
- Urvi M Parikh
- Division of Infectious Diseases, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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Abstract
PURPOSE OF REVIEW To summarize recent updates on the potential role of islatravir for HIV treatment and prevention. RECENT FINDINGS Islatravir is an investigational antiretroviral agent with unique pharmacologic properties that facilitate flexible dosing regimens. Islatravir has demonstrated potent antiviral activity and a high barrier to resistance when combined with doravirine and lamivudine. A simplified two-drug HIV treatment regimen of islatravir combined with doravirine has also demonstrated comparable efficacy to standard of care three-drug regimens. The long half-life and high potency of islatravir's active metabolite may support its use as a long-acting option for HIV preexposure prophylaxis (PrEP). A once monthly oral dose of islatravir maintains effective concentrations of its active metabolite over the entire dosing interval. Furthermore, an investigational implantable formulation has been projected to provide efficacious concentrations for at least a year and exhibits comparable distribution into vaginal and rectal tissues making it a promising PrEP option for male and female individuals. Islatravir has minimal risks of drug interactions as it is not a substrate, inducer, or inhibitor of major drug metabolizers and transporters. Finally, clinical trials demonstrate islatravir's favorable safety profile revealing only mild and transient adverse events. SUMMARY Leveraging the unique pharmacological properties of islatravir offers opportunities for simplified HIV treatment regimens and long-acting PrEP making it a valuable addition to the antiretroviral arsenal.
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Islatravir Has a High Barrier to Resistance and Exhibits a Differentiated Resistance Profile from Approved Nucleoside Reverse Transcriptase Inhibitors (NRTIs). Antimicrob Agents Chemother 2022; 66:e0013322. [PMID: 35546110 DOI: 10.1128/aac.00133-22] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Islatravir (ISL) is a nucleoside reverse transcriptase translocation inhibitor (NRTTI) that inhibits human immunodeficiency virus (HIV) reverse transcription by blocking reverse transcriptase (RT) translocation on the primer:template. ISL is being developed for the treatment of HIV-1 infection. To expand our knowledge of viral variants that may confer reduced susceptibility to ISL, resistance selection studies were conducted with wild-type (WT) subtype A, B, and C viruses. RT mutations encoding M184I and M184V were the most frequently observed changes. Selection studies were also initiated with virus containing a single known resistance-associated mutation in RT (K65R, L74I, V90I, M184I, or M184V), and no additional mutations were observed. Antiviral activity assays were performed on variants that emerged in selection studies to determine their impact. M184I and M184V were the only single-codon substitutions that reduced susceptibility >2-fold compared to WT. A114S was an emergent substitution that when combined with other substitutions further reduced susceptibility >2-fold. Viruses containing A114S in combination with M184V did not replicate in primary blood mononuclear cells (PBMCs), consistent with the rare occurrence of the combination in clinical samples. While A114S conferred reduced susceptibility to ISL, it increased susceptibility to approved nucleoside reverse transcriptase inhibitors (NRTIs). This differential impact of A114S on ISL, an NRTTI, compared to NRTIs likely results from the different mechanisms of action. Altogether, the results demonstrate that ISL has a high barrier to resistance and a differentiated mechanism compared to approved NRTIs.
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