PRAXIS EXPANDING AL 721 TRIAL IN AIDS-RELATED LYMPHADENOPATHY PATIENTS

PRAXIS EXPANDING AL 721 TRIAL IN AIDS-RELATED LYMPHADENOPATHY PATIENTS in an on-going Phase II trial at St. Luke's/Roosevelt Hospital Center in New York. An additional 50-80 patients will be enrolled in the trial that will last six months. A second trial using the same protocol will be conducted at a different site and will start at the beginning of next year. Within the next two or three months, Praxis will begin trials of the antiviral compound in more severely ill patients in the later stages of AIDS, those having full-blown AIDS and AIDS-Related Complex (ARC). Plans for the trials' protocols are presently being finalized. The trials are expected to last for four to twelve months. The initial trial at St. Luke's was an open, Phase II trial to test the efficacy of AL 721 in eight patients with AIDS-related complex. "The purpose of the trial was to learn if AL 721 could be effective in halting the progression of the disease without introducing a harmful toxin that would potentially destroy the body's host cells," Praxis stated in an Oct. 2 press release. In the early trial, AL 721 inhibited replication of the virus and patients that previously exhibited immune deficiency showed improved immune function, Praxis maintained. "Although the data is preliminary, it is significant that in six out of seven patients, we saw reductions in reverse transcriptase (RT) levels (the biochemical marker for the AIDS-causing HIV virus)," said Michael Grieco, MD, a trial supervisor. Praxis reported that over the two month period RT reductions averaged more than 80%. Praxis maintained that none of the patients showed signs of toxicity, which is "highly significant when compared with other drugs presently being tested and indicates that the drug may be one of the most promising in the fight against AIDS." AL 721 is unlike other AIDS drugs in that it does not interfere with the genetic apparatus of the AIDS virus, Praxis commented. A letter published in the Nov. 14, 1985 issue of The New England Journal of Medicine reported that AL 721 "does not directly inhibit reverse transcriptase [therefore it does] not produce the undesirable side effects. . ." AL 721 was also defined in the letter to be "a novel lipid compound that is composed of neutral glycerides, phosphatidylcholine, and phosphatidylethanolamine in a 7:2:1 ratio and has demonstrated ability to extract cholesterol from cellular membranes both in vitro and in vivo." The letter stated that the extraction of cholesterol modifies the active site on the viral membrane that causes interference of the binding process. "AL 721 interferes with the receptor-mediated process whereby the virus attaches to and infects the host cells," Arnold Lippa, PhD, president of Praxis, reported at a July 1 Hearing on AIDS Drug Development before the House Intergovernmental Relations Subcommittee. Lippa also commented at the hearing that "since the brain is one of the critical target sites for the AIDS virus, it is important to note that AL 721 readily penetrates into the brain where it may also exert therapeutic effects."