Lidak Pharmaceuticals Inc. may expand clinical development ofn-docosanol to include several new indications, the company'spresident and chief executive officer, David Katz, announcedTuesday.

Speaking at the International Society for Antiviral Research'sseventh annual conference in Charleston, S.C., Katz presenteddata showing the ability of n-docosanol to block infection intissue culture by herpes simplex virus, varicella zoster virus(which causes shingles), respiratory syncytial virus andcytomegalovirus (CMV). The agent has also been shown duringin vitro tests to be active against HIV and influenza viruses, hesaid.

These findings will affect Lidak's development plans for n-docosanol, which is currently in clinical development as atopical treatment for oral and genital herpes, Katz toldBioWorld. The company is in the midst of a U.S. Phase II trial ofLidakol (n-docosanol) for the treatment of oral herpes and hascompleted a European Phase II oral herpes study. Lidak iscompleting a protocol for a European Phase III trial of Lidakolfor oral herpes.

The company is now developing a systemic formulation of n-docosanol that could be used in treating some of the viralinfections that Lidak researchers have found the agent to beactive against. The company hopes to move into preclinicaltoxicology studies of the systemic n-docosanol by mid-year,Katz said. Lidak plans to design a single formulation that it candevelop for several different kinds of viral infection, he said.

Katz also presented Phase II results from a study of Lidakolthat was conducted in the Netherlands by the company'sEuropean licensee, Yamanouchi Europe (formerly BrocadesPharma b.v., which was acquired by YamanouchiPharmaceutical Co. Ltd.). The 63-patient trial evaluated theability of Lidakol to reduce healing time of lesions in patientswith herpes labialis (oral herpes).

The results showed that 70 percent of 13 patients who weretreated with Lidakol (n-docosanol) at the early prodrome orerythema stage of herpes outbreak had no furtherdevelopment of lesions, vs. 29 percent of seven patients onplacebo.

The study also found that early-treatment patients experienceda reduction in mean healing time of 3.3 days over those onplacebo. These results included patients who were treated formore than one outbreak of herpes lesions during the study;early-treatment patients experienced a 4.3-day meanreduction in healing time for their first outbreak.

Results were less robust for patients treated after thedevelopment of herpes papules. Reduction in healing time wasnot statistically significant for these late-treatment patientsexcept for a group that was initially treated with placebo andwere switched to Lidakol after a second outbreak. Thesepatients experienced a 2.4-day mean reduction in healing oflesions over placebo.

For all 98 episodes of oral herpes examined in the 63 patients,with either early or late treatment, Lidakol was associated witha statistically significant 1.6-day reduction in mean healingtime over placebo.

Last July the company announced preliminary results from thisstudy, which began in November 1992. Lidak is still discussingNorth American marketing rights for Lidakol for oral andgenital herpes. European marketing rights for use of topical n-docosanol in the treatment of topical viral infection belong toYamanouchi Europe, and Israeli company CTS ChemicalIndustries Ltd. has rights to Lidakol in Israel.

-- Karl A. Thiel Business Editor

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