Protein Design Labs Inc. began enrolling participants fora 325-patient Phase II/III trial, sponsored by the NationalEye Institute, to test the effectiveness of the company'shuman monoclonal antibody in treatment of AIDS-relatedcytomegalovirus (CMV) retinitis.

The study, which Protein Design officials said representsthe largest placebo-controlled trial for CMV retinitis, willexamine the antibody, called MSL 109, in combinationwith one of two FDA approved antiviral drugs, eitherfoscarnet or ganciclovir. The former is marketed bySweden-based Astra AB and the latter is sold bySwitzerland-based Roche Holdings Ltd.

The National Eye Institute, part of the National Institutesof Health (NIH), of Bethesda, Md., will conduct the trialsat 14 U.S. medical centers.

Patients will receive one of the two approved drugs witha placebo or with 60 mg of monoclonal anti-CMVantibody once every two weeks. CMV is a progressivedisease and current therapies keep the virus in check forbetween 60 and 100 days, after which patients experiencerelapses and the virus spreads.

Peter Dworkin, Protein Design's director of corporatecommunications, said the primary endpoint of the PhaseII/III study is to determine if the monoclonal antibody canlengthen the time of remissions. Survival, preservation ofvisual function and number of hospitalizations aresecondary goals.

CMV is a common infection that becomes life-threatening in people whose immune systems arecompromised, such as AIDS patients and organ transplantrecipients.

Protein Design, which has two clinical trials under wayfor AIDS-related CMV retinitis, also is testing theantibody in a Phase II study for prevention of CMV incancer patients who undergo bone marrow transplants.

Dworkin said more than 30,000 of the estimated 200,000AIDS patients in the U.S. have CMV and another 10,000transplant recipients are infected.

In addition to the National Eye Institute trial, a Phase IIstudy of the monoclonal antibody for AIDS-related CMVretinitis was started in July by the NIH's NationalInstitute of Allergy and Infectious Diseases.

Protein Design licensed the anti-CMV antibody fromSwitzerland-based Sandoz Ltd., which has an option forco-promotion and co-marketing in North America.Protein Design licensed European marketing rights toBermuda-based Corange Ltd.

Dworkin said Protein Design envisions using themonoclonal antibody in combination with other therapies.The design of the Phase II/III National Eye Institute studywould allow physicians to test the antibody in associationwith treatments other than ganciclovir and foscarnet asthey are approved by the FDA.

Companies such as Chiron Corp., of Emeryville, Calif.,Gilead Sciences Inc., of Foster City, Calif., and IsisPharmaceuticals Inc., of Carlsbad, Calif., are evaluatingCMV retinitis therapies in late-stage clinicaldevelopment.

Protein Design (NASDAQ:PDLI) Thursday closed up$1.75 to $20.38, a 9 percent jump. n

-- Charles Craig

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