Agouron Pharmaceuticals Inc. reported Friday that its proteaseinhibitor showed anti-HIV activity in the first patients tested in aPhase II pilot study.

Preliminary data about AG1343 were presented at a meeting of theInternational Society of Antiviral Research in Sante Fe, N.M. Phase Idata of the compound, released earlier this year, showedbioavailability in non-infected patients and no significant adverseevents.

Peter Johnson, president and CEO of La Jolla, Calif.-based Agouron,said he announced the early results at this stage to help with the"cloud hanging over the class of protease inhibitors after thecompound being developed by G. D. Searle [& Co.] failed to showanti-HIV activity after it got into infected patients."

"The Searle results were such a surprise that we felt it was important,even on the basis of rather early data, to make it clear the Agouroncompound does not suffer from that particular problem," Johnsontold BioWorld.

Johnson said it's not clear exactly what happened with Skokie, Ill.-based Searle's drug, although some attributed the failure to excessprotein binding. And, he said, it's not clear why AG1343 didn'tsuffer the same fate.

In any case, he said, the proof is in showing some anti-HIV activity."And that much we have been able to clearly report today."

The Phase II pilot study will include about 25 patients given variousdoses of the drug for 28 days. Objectives are to confirm the favorablepharmacokinetic profile seen earlier and to assess anti-viral activity.The study is being conducted in the Kobler Center at the Chelsea-Westminster Hospital, London.

Agouron's senior clinical research scientist, Sharon Chapman,reported Friday that 300 mg of AG1343 in capsules have beenadministered three times per day to eight patients, for period rangingfrom three to 28 days. The patients had more than 20,000 copies ofHIV and 200 to 500 CD4+ T cells per cubic millimeter of blood.

The first patient who entered and completed the study had a reductionof HIV in the blood of more than 99 percent and an increase in CD4+T cells of 116. Johnson said that patient started the study with 356CD4 cells.

Chapman also reported that levels of AG1343 in the blood weresimilar to concentrations seen in non-infected subjects.

"The anti-HIV activity seen in the first patient was never seen withthe Searle compound," Johnson said. "Based on what we've seen inother patients [in the pilot study], we believe he will not be unique.We do have an active drug, and that's the only real message weintended to convey at this point. We're not going to be in for thatkind of terrible surprise Searle had when they had no activity inpatients."

Johnson said two or three doses are going to be tested, and the studyshould be completed in two or three months. At that point results willbe presented to collaborator Japan Tobacco Inc., of Tokyo, whichalready has paid Agouron $6 million, and will pay another $24million upon satisfactory results from the Phase II pilot study.

The two companies then would share development costs. ButAgouron wouldn't have to pay more than $15 million of its share ofdevelopment costs until after the drug is approved.

Agouron's stock (NASDAQ:AGPH) was up 75 cents Friday, closingat $18.75 per share. n

-- Jim Shrine

(c) 1997 American Health Consultants. All rights reserved.