BioWorld International Correspondent

LONDON - Medical Marketing International Group plc (MMI) released new data on its portfolio of ruthenium compounds that it claims show the compounds have the potential to form a new class of cancer therapeutic.

Not only are the compounds on average more potent than platinum-based therapeutics, but individual analogues show specificity for certain tumor cell lines, and are more effective against them than cisplatin or carboplatin, it said.

The ruthenium compounds were licensed from Edinburgh University a year ago by MMI's subsidiary, Oncosense Ltd. David Best, executive chairman of MMI, based in Cambridge, said he is seeking third-party funding to enable Oncosense to take the compounds into the clinic.

"Oncosense has not raised any money on its own behalf and so far is wholly owned," he said. "We are talking to third parties and there is significant interest. Oncosense is probably worth more now than we originally anticipated so we will probably put more money in ourselves."

The Edinburgh researchers are not the only group exploring the use of ruthenium-based compounds as chemotherapeutics, but Best said they are the first to demonstrate specificity for different tumor types.

That is achieved by manipulating the side chains of the molecule. "We think we understand the mechanism of action [of ruthenium] so we can tweak the side chains to optimize [efficacy] for different cancer cell lines," Best said. The method used to attach the side chains is proprietary, and Best said there is a firm patent position.

Toxicological studies are not complete but Best said the evidence so far is that the ruthenium compounds are less toxic than their platinum-based counterparts.

The scientists have produced a number of analogues, including ones that are specific for non-small-cell lung cancer, breast cancer and melanoma. Best said the original plan was to select the best candidate and get that into the clinic. "We have now changed strategy and will select a number of candidates to treat different tumors."

Oncosense is talking to UK regulators about conducting Phase IIa trials in patients who have failed existing therapies, and Best said he is hopeful of starting trials in one or two tumor types before the end of 2003.