Clinical Trials of Isis 2503 Anticancer Compound Initiated

Isis Pharmaceuticals (Carlsbad, CA) has initiated a Phase II clinical trial of Isis 2503, its third antisense anticancer compound in clinical development. In the trial, Isis 2503 will be evaluated as a single-agent in patients with colon, breast, pancreatic, and non-small cell lung cancers. Approximately ten sites in the U.S. and Europe will enroll 15–30 patients per tumor type in these trials.

Isis 2503 is a potent, selective antisense inhibitor of H-ras gene expression. H-ras is one of a family of ras genes that are involved in the process by which cells receive and send signals that affect their behavior. Substantial evidence exists to support a direct role for the ras gene products in the development and maintenance of human cancers.

In Phase I testing, Isis 2503 demonstrated an encouraging safety profile in patients with solid tumors. The compound was well-tolerated, with no clinically significant toxicities observed among 22 patients with a variety of solid tumors who received the drug by 14-day continuous infusion repeated every 21 days. This same schedule will be used in the Phase II trials. Prolonged stable disease was observed in 4 patients on this trial, including one patient with pancreatic cancer who had disease stabilization for 8 treatment courses administered over 6 months.

Isis also plans to initiate Phase I trials to examine the use of Isis 2503 in combination with approved chemotherapies later this year.

Isis Pharmaceuticals is engaged in the discovery and development of novel human therapeutic compounds.

For more information: Isis Pharmaceuticals, 2292 Faraday Ave., Carlsbad, CA 92008. Tel: 760-931-9200. Fax: 760-931-9639.