Thursday, February 3, 2000 RETROVIRUSES CONFERENCE PROTEASE INHIBITORS: Drug Companies Seek Treatments to Reduce Pill Intake       Several pharmaceutical companies are developing more effective, lower dosed AIDS treatments that could reduce the pill burden for patients to just four tablets taken once-daily, according to researchers at the Seventh Conference on Retroviruses and Opportunistic Infections (Healy, USA Today, 2/3). Current treatments require patients to strictly adhere to regimens that contain more than 20 pills taken at several times throughout the day. Patients who miss even a few doses run the risk of developing a mutated virus that could be resistant to existing treatment. Experts believe that nearly half of all patients who respond to initial treatment experience a rebound in viral load because they are unable to adhere to the drug regimen (Haney, AP/Contra Costa Times, 2/3). "Everyone wants a simpler dosing schedule," according to Dr. Ian Sanne, a South African research physician, who presented results from a small study of a new Bristol-Myers Squibb protease inhibitor. In that study, Sanne followed 93 patients who were placed on a cocktail of the new protease plus two older Bristol-Myers antiretrovirals, Videx and Zerit. After 16 weeks, Sanne found that the combination was as effective as existing therapies in reducing the viral load to undetectable levels. Research is now being conducted to assess the combination's long-term efficacy and a larger study involving 632 patients is planned. In addition, Bristol-Myers is working on new single-dose formulations of Videx and Zerit (Waldholz, Wall Street Journal, 2/3). Drug manufacturer Abbott Laboratories also presented a study that showed its new protease inhibitor ABT-378 was effective in fighting already-resistant strains of HIV. The drug, when combined into a pill with the company's FDA-approved protease ritonavir, can be dosed at three pills twice-daily. The company is working on reducing that dosage (AP/Contra Costa Times, 2/3). However, developing new drugs or improving older treatments is not always easy. Merck planned to present results from its new twice-daily protease MK-944A, but studies were halted two weeks ago due to kidney toxicity in laboratory rats. Still, many researchers were optimistic (Wall Street Journal, 2/3). Dr. Eugene Sun, director of antiviral research at Abbott, said, "Most drugs are dosed twice or three times a day for a reason. Once a day is not enough. The Holy Grail would be to take all your medications once a day with as few capsules as possible. We are not so far from that, maybe the next couple of years" (AP/Contra Costa Times, 2/3). Kaiser Daily HIV/AIDS Report