Antisoma Phase 1 Study

Nigel Courtenay-Luck, Ph.D., CSO of Antisoma, at a recent 9th European Biotech Crossroads meeting, talked about data from Phase 1 of a study on a new type of biomolecule called an aptamer. He said that aptamers are very similar to antibodies; they can both recognize and bind to antigens, they both have low nanomolar binding, and the pKa of both molecules can be modified easily. He said that they are ideal to be used as therapeutics because they can bind well(since they are 3-D) without causing an immunogenic response(since they are small). At this meeting, Dr. Courtenay-Luck showed preclinical and Phase 1 trials for an aptamer called AS1411, an aptamer that recognizes and binds to nucleolin, “a major nuclear phosphoprotein that is found on the surface of many solid tumors” but not really seen on the surface of noncancerous cells.

In the Phase 1 study, 17 patients with all sorts of solid tumors were treated for up to 7 days with a dose of 110 mg/kg of AS1411 per day. The results were that there was no “severe toxicity” to the patient seen at levels that would cause them to recover. AS1411 has only a small amount of toxicity because it can leave the blood very quickly; it has a half-life of only 20 minutes or less. Clinical trials are now evaluating AS1411 to be used to treat