HIV AIDS News [International Conference on AIDS (12th: 1998: Geneva, Switzerland)]

Efavirenz is a novel new non-nucleoside reverse transcriptase
inhibitor (NNRTI) that combines high potency and good tolerability with
convenient once-daily dosing, due to the drug's long half-life. In addition,
efavirenz has been shown to penetrate the blood-brain barrier. Researchers
believe that an antiviral agent that attacks HIV in the brain may limit reproduction
of the virus in this 'reservoir' area of the body.
Discovered in the research laboratories of Merck & Co., Inc., New Jersey
USA, in 1991, efavirenz was licensed to DuPont Pharma, which continued
clinical development. Today, MSD and DuPont Pharma will share the marketing
of the drug around the world. The two companies this week announced a joint
filing of an application to market efavirenz under the European Union's
centralised licensing procedure.
Positive Study Results
Two studies being presented this week have examined the new
CRIXIVAN + efavirenz combinations, Merck Protocol 067 and DMP 266-003,
Cohort IV.
Protocol 067, examined CRIXIVAN taken two- or three-times-a-day in
combination with efavirenz. A total of 71 patients were randomised to CRIXIVAN
twice-daily (1200mg q12h) plus efavirenz twice-daily (300 mg q12h) as opposed
to three-times-a-day CRIXIVAN (1000mg q8h) with efavirenz once-daily (600mg
qd).
After 16 weeks of therapy, six out of seven patients in the CRIXIVAN
three-times-a-day arm had undetectable levels of viral load (<400 copies/ml),
compared to six out of eight in the twice-daily arm. Study drugs were generally
well tolerated, with two patients in the twice-daily group and one in the threetimes-a-day group discontinuing due to adverse events.