Agouron Starts Phase III Protease Inhibitor Studies

Agouron Pharmaceuticals, Inc. is starting two large studies of its protease inhibitor VIRACEPT(TM) (nelfinavir mesylate) in combination with approved HIV drugs. A smaller study of nelfinavir alone is also beginning.

One trial, protocol 506, will study two doses of nelfinavir (500 and 750 mg) combined with stavudine (d4T), vs. stavudine alone. Volunteers will have a two-thirds chance of getting one of the combination regimens. This trial will enroll 240 patients; three quarters of the slots are for persons who have been treated with AZT for at least six months, and the other 25% are for those who have either had no AZT use, or less than six months of it. Volunteers must be at least 13 years old, and must have a CD4 count of at least 50 and a viral load of at least 15,000 copies. They cannot have used any protease inhibitor, nor d4T, at any time. In case of treatment failure (defined as return to baseline viral load, CD4, or both on two consecutive visits following four weeks of drug administration), certain treatment changes will be allowed. This study will last 24 weeks, and may provide drug for an additional six months.
Another trial, protocol 511, will study the same two doses of nelfinavir in combination with AZT plus 3TC, vs. AZT plus 3TC alone. Volunteers will have a two-thirds chance of getting a triple combination treatment. They must be at least 13 years old, and have a viral load of at least 15,000 copies. They can have any CD4 count, but cannot have received any anti-HIV drugs except for a lifetime total of less than one month of AZT. This study will last for 24 weeks, after which drug may be provided for another six months. Provisions similar to protocol 506 are available for treatment failure. This study is seeking to enroll 210 patients.

Protocol 505 will study the same two doses of nelfinavir alone, compared to placebo. After four weeks, the placebo volunteers will be randomized into one of the treatment groups. Volunteers must have a CD4 count of at least 50, and a viral load of at least 15,000.

For more information about these trials, which are now recruiting in about 30 cities in the U.S., call Agouron's information line, 800/501-2474, and follow the voicemail instructions to find a contact number in your city.

Comment

It is difficult for patients and physicians to make decisions about protease inhibitor therapies at this time. The main disadvantage of the Agouron drug is that much less is known about it than is known about the Merck, Abbott, or Roche protease inhibitors. On the other hand, it may not have some of the drawbacks of those other drugs. For today and for the near future, there is no way to know which treatment options are best.