Cytopia has received the green light to trial a promising new drug that could prove effective in the fight against advanced solid tumours. In animal studies, the drug candidate has already shown efficacy in killing cancer cells in prostate, colon and breast cancer.
Australian biotechnology company Cytopia plan to involve 30 patients with advanced incurable tumours in experiments using the drug candidate CYT997 in what will be the start of human trials.
CYT997 is a potent wholly-synthetic small molecule that has potent anticancer properties. Technically, it is cytotoxic, disrupting microtubule formation by interacting with tubulin.
Cancer cells known to be expressing MDR phenotype were not resistant to the potent cell inhibitory effects of CYT997. In subcutaneous and orthotopic animal efficacy studies, orally administered CYT997 significantly inhibited primary tumour growth of experimentally grafted human and mice cancer cells without adverse effects.
Dr Andrew Wilks, Cytopia's chief scientific officer, said the Phase I study would be a non-blinded, dose escalation study in patients with various cancers and could take between nine and twelve months. "Patients will receive CYT997 by intravenous infusion once every three weeks for up to six cycles," Dr Wilks said.
The primary goals of this new study are to evaluate the safety and tolerability of CYT997, to assess its behaviour in vivo and to establish a safe dose of CYT997 for subsequent Phase II clinical trials.
"In addition, we will be looking for signs that the drug is having an effect on the cancers, particularly at higher doses," he said.
Cytopia managing director, Dr Kevin Healey, said the company had obtained the necessary ethics approvals to begin clinical trials. He added the drug would be effective when taken orally which would be a major benefit for patients.
"CYT997 appears to avoid some of the mechanisms that enable tumours to become resistant to existing first line drugs," he said.
"We are very excited about a number of features of the drug. It has a dual mode of action, directly killing cancer cells and at the same time starving the cancer of its blood supply. Cancers rely on this blood supply for their growth," said Healy.
According to the American Cancer Society, there will be about 1.3 million new cases of cancer in the US in 2005, not including skin cancers. Approximately 570,000 deaths are expected in 2005 in the US alone. The National Institutes of Health estimate direct medical costs for cancer in 2004 at $69.4 billion (€53.7 billion).