A Short-Term Clinical Evaluation of L-697,661, a Non-Nucleoside Inhibitor of HIV-1 Reverse Transcriptase
Michael S. Saag, Emilio A. Emini, Oscar L. Laskin, Jeffrey Douglas, William I. Lapidus, William A. Schleif, Richard J. Whitley, Carol Hildebrand, Vera W. Byrnes, John C. Kappes, Kevin W. Anderson, Ferdinand E. Massari, George M. Shaw, for The 661 Working Group L-697
Background The non-nucleoside reverse transcriptase inhibitorsare novel antiretroviral agents with selective activity in vitroagainst human immunodeficiency virus type 1 (HIV-1). They actthrough direct inhibition of reverse transcriptase and are notincorporated into DNA.
Methods We evaluated a pyridinone non-nucleoside reverse transcriptaseinhibitor, L-697,661, in separate six-week double-blind trialsin patients with HIV-1 infection whose CD4 counts ranged from200 to 500 cells per cubic millimeter (68 patients) or lessthan 200 cells per cubic millimeter (67 patients). Eligiblepatients were randomly assigned to receive L-697,661 orallyin one of three doses (25 mg twice a day, 100 mg three timesa day, or 500 mg twice a day) or zidovudine (100 mg five timesa day). Clinical and laboratory assessments were performed weekly.Viral isolates were obtained from a subgroup of patients beforeand after treatment and were evaluated for in vitro sensitivityto L-697,661.
Results Both L-697,661 and zidovudine were well tolerated. Transientincreases in CD4 counts were noted in the patients with fewerthan 200 CD4 cells per cubic millimeter who received the twohigher doses of L-697,661, but not in those who received thelowest dose or zidovudine. Patients who received L-697,661 hadrapid, dose-related decreases in plasma p24 antigen levels.However, this response virtually disappeared after six weeksin some patients receiving L-697,661, coincidently with theemergence of resistant viruses. This change in susceptibilitywas more frequent among patients receiving the higher dosesof L-697,661 and was associated with amino acid substitutionsat positions 103 and 181 in the HIV-1 reverse transcriptasegene.
Conclusions L-697,661 is safe and well tolerated and has significantdose-related activity against HIV-1. However, resistant strainsof the virus emerge rapidly and may limit the effectivenessof non-nucleoside reverse transcriptase inhibitors as monotherapyfor HIV-1 infection.
Source Information
From the Department of Medicine, University of Alabama at Birmingham (M.S.S., J.D., W.I.L., R.J.W., J.C.K., G.M.S.), and Merck Research Laboratories, West Point, Pa. (E.A.E., O.L.L., W.A.S., C.H., V.W.B., K.W.A., F.E.M.). The members of the L-697,661 Working Group are listed in the Appendix.
Address reprint requests to Dr. Saag at the University of Alabama at Birmingham, 908 S. 20th St., #245B, Birmingham, AL 35294-2050.
Hazuda, D. J., Anthony, N. J., Gomez, R. P., Jolly, S. M., Wai, J. S., Zhuang, L., Fisher, T. E., Embrey, M., Guare, J. P. Jr., Egbertson, M. S., Vacca, J. P., Huff, J. R., Felock, P. J., Witmer, M. V., Stillmock, K. A., Danovich, R., Grobler, J., Miller, M. D., Espeseth, A. S., Jin, L., Chen, I-W., Lin, J. H., Kassahun, K., Ellis, J. D., Wong, B. K., Xu, W., Pearson, P. G., Schleif, W. A., Cortese, R., Emini, E., Summa, V., Holloway, M. K., Young, S. D.
(2004). From the Cover: A naphthyridine carboxamide provides evidence for discordant resistance between mechanistically identical inhibitors of HIV-1 integrase. Proc. Natl. Acad. Sci. USA
101: 11233-11238
[Abstract][Full Text]
Huang, W., Gamarnik, A., Limoli, K., Petropoulos, C. J., Whitcomb, J. M.
(2002). Amino Acid Substitutions at Position 190 of Human Immunodeficiency Virus Type 1 Reverse Transcriptase Increase Susceptibility to Delavirdine and Impair Virus Replication. J. Virol.
77: 1512-1523
[Abstract][Full Text]
Grant, R. M., Hecht, F. M., Warmerdam, M., Liu, L., Liegler, T., Petropoulos, C. J., Hellmann, N. S., Chesney, M., Busch, M. P., Kahn, J. O.
(2002). Time Trends in Primary HIV-1 Drug Resistance Among Recently Infected Persons. JAMA
288: 181-188
[Abstract][Full Text]
Wei, X., Decker, J. M., Liu, H., Zhang, Z., Arani, R. B., Kilby, J. M., Saag, M. S., Wu, X., Shaw, G. M., Kappes, J. C.
(2002). Emergence of Resistant Human Immunodeficiency Virus Type 1 in Patients Receiving Fusion Inhibitor (T-20) Monotherapy. Antimicrob. Agents Chemother.
46: 1896-1905
[Abstract][Full Text]
Buckheit, R. W. Jr., Watson, K., Fliakas-Boltz, V., Russell, J., Loftus, T. L., Osterling, M. C., Turpin, J. A., Pallansch, L. A., White, E. L., Lee, J.-W., Lee, S.-H., Oh, J.-W., Kwon, H.-S., Chung, S.-G., Cho, E.-H.
(2001). SJ-3366, a Unique and Highly Potent Nonnucleoside Reverse Transcriptase Inhibitor of Human Immunodeficiency Virus Type 1 (HIV-1) That Also Inhibits HIV-2. Antimicrob. Agents Chemother.
45: 393-400
[Abstract][Full Text]
Demeter, L. M., Shafer, R. W., Meehan, P. M., Holden-Wiltse, J., Fischl, M. A., Freimuth, W. W., Para, M. F., Reichman, R. C.
(2000). Delavirdine Susceptibilities and Associated Reverse Transcriptase Mutations in Human Immunodeficiency Virus Type 1 Isolates from Patients in a Phase I/II Trial of Delavirdine Monotherapy (ACTG 260). Antimicrob. Agents Chemother.
44: 794-797
[Abstract][Full Text]
Buckheit, R. W. Jr., White, E. L., Fliakas-Boltz, V., Russell, J., Stup, T. L., Kinjerski, T. L., Osterling, M. C., Weigand, A., Bader, J. P.
(1999). Unique Anti-Human Immunodeficiency Virus Activities of the Nonnucleoside Reverse Transcriptase Inhibitors Calanolide A, Costatolide, and Dihydrocostatolide. Antimicrob. Agents Chemother.
43: 1827-1834
[Abstract][Full Text]
Para, M. F., Meehan, P., Holden-Wiltse, J., Fischl, M., Morse, G., Shafer, R., Demeter, L. M., Wood, K., Nevin, T., Virani-Ketter, N., Freimuth, W. W.
(1999). ACTG 260: a Randomized, Phase I-II, Dose-Ranging Trial of the Anti-Human Immunodeficiency Virus Activity of Delavirdine Monotherapy. Antimicrob. Agents Chemother.
43: 1373-1378
[Abstract][Full Text]
Patick, A. K., Potts, K. E.
(1998). Protease Inhibitors as Antiviral Agents. Clin. Microbiol. Rev.
11: 614-627
[Abstract][Full Text]
Goldschmidt, P. L., Devillechabrolle, A., Ait-Arkoub, Z., Aubin, J.-T.
(1998). Comparison of an Amplified Enzyme-Linked Immunosorbent Assay with Procedures Based on Molecular Biology for Assessing Human Immunodeficiency Virus Type 1 Viral Load. CVI
5: 513-518
[Abstract][Full Text]
Hirsch, M. S., Conway, B., D'Aquila, R. T., Johnson, V. A., Brun-Vezinet, F., Clotet, B., Demeter, L. M., Hammer, S. M., Jacobsen, D. M., Kuritzkes, D. R., Loveday, C., Mellors, J. W., Vella, S., Richman, D. D., for the International AIDS Society-USA Panel,
(1998). Antiretroviral Drug Resistance Testing in Adults With HIV Infection: Implications for Clinical Management. JAMA
279: 1984-1991
[Abstract][Full Text]
Eastman, P. S., Mittler, J., Kelso, R., Gee, C., Boyer, E., Kolberg, J., Urdea, M., Leonard, J. M., Norbeck, D. W., Mo, H., Markowitz, M.
(1998). Genotypic Changes in Human Immunodeficiency Virus Type 1 Associated with Loss of Suppression of Plasma Viral RNA Levels in Subjects Treated with Ritonavir (Norvir) Monotherapy. J. Virol.
72: 5154-5164
[Abstract][Full Text]
Carpenter, C. C. J., Fischl, M. A., Hammer, S. M., Hirsch, M. S., Jacobsen, D. M., Katzenstein, D. A., Montaner, J. S. G., Richman, D. D., Saag, M. S., Schooley, R. T., Thompson, M. A., Vella, S., Yeni, P. G., Volberding, P. A.
(1996). Antiretroviral Therapy for HIV Infection in 1996: Recommendations of an International Panel. JAMA
276: 146-154
[Abstract]
O'Brien, W. A., Hartigan, P. M., Martin, D., Esinhart, J., Hill, A., Benoit, S., Rubin, M., Simberkoff, M. S., Hamilton, J. D.
(1996). Changes in Plasma HIV-1 RNA and CD4+ Lymphocyte Counts and the Risk of Progression to AIDS. NEJM
334: 426-431
[Abstract][Full Text]