Isis antisense drug delays tumour growth

Shares of California-based Isis Pharmaceuticals rose as much as 13 per cent on Thursday after it said its experimental anti-cancer compound significantly delayed tumour growth and increased the rate of malignant cell death in cell and animal models.

While the data is extremely early, scientists and investors tend to watch developments at Isis with interest as its products are based on a technology known as "antisense" which is designed to arrest the progress of disease at an earlier stage than traditional therapies.

Isis said early research showed that by inhibiting a protein known as STAT-3 that regulates cell division and growth and prevents cell death, Isis' experimental drug, known as ISIS 345794, was able to slow tumour growth.

The data was presented at a conference in London. The company said STAT-3, or signal transducer and activator of transcription 3, is a compelling target for clinical development because the protein is expressed in a wide range of solid and blood cancers.

Isis said it intends to initiate human trials of the drug in 2005.

ISIS 345794 is a second-generation antisense drug, which the company hopes might overcome some of the problems of the first-generation drugs. Many times the drugs have worked in animals only to fail in humans.

Researchers have struggled for more than 30 years to turn the promise of an elegant theory into practical reality. Isis is one of the technology's most fervent advocates.