Staff Writer

Anadys Pharmaceuticals Inc. and Gilead Sciences Inc. entered a collaboration to discover antiviral compounds using Anadys' technology and Gilead's undisclosed viral target.

San Diego-based Anadys, a private company, will employ its Atlas ultra-high-throughput screening technology to design and run assays against Gilead's compound collection, and Gilead, of Foster City, Calif., will have exclusive rights to develop and commercialize any resulting products.

Anadys will receive an up-front payment, research and development funding, milestones and royalties, said CEO Kleanthis Xanthopoulos.

"It clearly validates [Atlas, which is] something we have been developing for quite some time," he said. "A partner like Gilead allows us to raise that to a completely different level," and to enter antivirals, he added.

The Atlas technology allows for affinity-based screening of 100,000 compounds in one day, the company said, adding that it uses discrete compounds, mixtures or natural products to screen for small molecules that bind to proteins that are difficult to screen using conventional methods.

"The goal is to take this challenging but extremely interesting viral target, configure the assay in a format so that we can apply our proprietary screening technology, and then screen a large amount of Gilead-selected compounds," Xanthopoulos said. "We will identify and verify those original chemical hits and then investigate if there is a basis to deploy our high-out medicinal chemistry."

Anadys and Gilead will collaborate "as long as it takes to make that very difficult target produce some interesting leads so that we can apply medicinal chemistry," he told BioWorld Today. Gilead reviewed "a number of" screening technologies before deciding on his company's method, he added.

In February, Anadys and Structural GenomiX, also of San Diego, announced a joint partnership to discover small-molecule antibacterial drugs, an agreement that also was to use the Atlas technology. A month later, Anadys reported that it developed for the first time a database that includes the annotation of the portion of the human genome that encodes for proteins that interact with DNA. (See BioWorld Today, March 14, 2002, and Feb. 21, 2002.)

Gilead, also in March, submitted a new drug application to the FDA for adefovir dipivoxil, a drug for hepatitis B. The company requested a six-month priority review. The drug is a nucleotide analogue that works by blocking the hepatitis B virus DNA polymerase, an enzyme responsible for replicating the virus. (See BioWorld Today, March 25, 2002.)

Last fall, Gilead won FDA approval for an HIV drug, Viread (tenofovir disoproxil fumarate), a nucleotide analogue reverse transcriptase inhibitor. The once-daily drug was launched in the United States in October and in Europe in February.

Gilead's stock (NASDAQ:GILD) rose 92 cents Monday to close at $32.91.