Identification of MK-944a: a second clinical candidate from the hydroxylaminepentanamide isostere series of HIV protease inhibitors.
Recent results from human clinical trials have established the critical role of HIV protease inhibitors in the treatment of acquired immune-deficiency syndrome (AIDS). However, the emergence of viral resistance, demanding treatment protocols, and adverse side effects have exposed the urgent need for a second generation of HIV protease inhibitors. The continued exploration of our hydroxylaminepentanamide (HAPA) transition-state isostere series of HIV protease inhibitors, which initially resulted in the identification of Crixivan (indinavir sulfate, MK-639, L-735,524), has now yielded MK-944a (L-756,423). This compound is potent, is selective, and competitively inhibits HIV-1 PR with a K(i) value of 0.049 nM. It stops the spread of the HIV(IIIb)-infected MT4 lymphoid cells at 25.0-50.0 nM, even in the presence of alpha(1) acid glycoprotein, human serum albumin, normal human serum, or fetal bovine serum. MK-944a has a longer half-life in several animal models (rats, dogs, and monkeys) than indinavir sulfate and is currently in advanced human clinical trials.
Dorsey
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BD
Departments of Medicinal Chemistry, Antiviral Research, Drug Metabolism, and Molecular Systems, Merck Research Laboratories, West Point, Pennsylvania 19486, USA. bruce_dorsey@merck.com
McDonough
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McDaniel
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Levin
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Newton
C L
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Hoffman
J M
JM
Darke
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Zugay-Murphy
J A
JA
Emini
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Schleif
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Olsen
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Stahlhut
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Rutkowski
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Kuo
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Lin
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Chen
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Michelson
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Holloway
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Huff
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Vacca
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D000818:Animals; D000998:Antiviral Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D002417:Cattle; D018929:Cell Culture Techniques; D004285:Dogs; D004353:Drug Evaluation, Preclinical; D004352:Drug Resistance, Microbial; D017320:HIV Protease Inhibitors / Q000138:chemical synthesis* / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D015497:HIV-1 / Q000187:drug effects*; D000882:Haplorhini; D006801:Humans; D007189:Indans / Q000138:chemical synthesis* / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D008297:Male; D010879:Piperazines / Q000138:chemical synthesis* / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D011485:Protein Binding; D051381:Rats; D017207:Rats, Sprague-Dawley; D013329:Structure-Activity Relationship; D014545:Urinary Calculi / Q000139:chemically induced / Q000652:urine
D000998:Antiviral Agents; D017320:HIV Protease Inhibitors; D007189:Indans; D010879:Piperazines; C122089:L 756423