LONDON ¿ Cantab Pharmaceuticals plc, of Cambridge, which is focused on immunotherapy, released data from the Phase I trial of its anti-cocaine vaccine, TA-CD, showing that it elicited a dose-related antibody response in all of the 34 subjects, and that the antibody was capable of recognizing free cocaine in the blood.

The results of the double-blind, placebo-controlled, dose-escalation study, conducted at a drug rehabilitation clinic in New England, were presented at the meeting of the College on Problems of Drug Dependence in Acapulco, Mexico.

The principal investigator, Thomas Kosten, said TA-CD ¿offers the potential for a new and highly viable approach to a very serious problem for which there are no alternative pharmacotherapies available.¿

The trial was funded by the U.S. National Institute on Drug Abuse.

Cantab said the early data endorse the rationale of its substance addiction vaccine programs. A Phase II trial of TA-CD is planned for the second half of 1999, and a second vaccine, TA-NIC, an anti-nicotine product, is ready for Phase I trials.

They consist of cocaine or nicotine linked to a carrier protein molecule, with alum as adjuvant. They work in the same way as traditional vaccines, generating antibodies, which bind to the drugs in the bloodstream, preventing them from reaching the brain and hence neutralizing the psychoactive effect. The vaccines would be administered only to people wanting to overcome addiction, as part of a behavioral therapy program.

The vaccines would not abolish existing cravings, but would prevent users from getting a further high and thus fuelling the addiction.

Cantab acquired the two compounds from ImmuLogic Pharmaceutical Corp., of Waltham, Mass., in December 1998, paying the equivalent of US$9 million in shares. In return, it got the two vaccines plus US$6 million in cash to fund development to the end of 2000.