Chemgenex drug shows stamina

Chemgenex (ASX: CXS) has provided updated results from its Phase I /II clinical study of anti-cancer drug Quinamed at the American Association for Cancer Research's Oncogenomics 2005 conference in the US.

Earlier results for the trial were announced last June, showing promising results for the drug in 32 patients with advanced prostate, ovarian and gastric cancer.

The update provides further details on the patients in the trial and information on four patients who have continued to benefit from the drug, One patient with hormone refractory prostate cancer has experienced a 40 per cent reduction in tumour volume and a 50 per cent decrease in the levels of the tumour marker prostate specific antigen, while two patients with ovarian cancer have demonstrated stabilisation of tumour growth and in one case, reduction in levels of tumour specific marker CA125. A fourth patient with metastatic gastrointestinal stromal cancer has continued to respond to the drug after 16 months of treatment.

The company is now evaluating Quinamed in a Phase II trial for hormone refractory prostate cancer. The drug has a unique feature -- dosage can be tailored to the patient based on their metabolic response to the drug, which depends on which alleles of the N-acetyltransferase 2 (NAT-2) gene the patient has, minimising side effects from the drug.

"We are very encouraged by these prolonged clinical responses in heavily pre-treated patients and are continuing to explore the use of Quinamed and its dosing based on NAT-2 genotype in a variety of solid tumours," said CEO Greg Collier.

The company also presented data from pre-clinical studies demonstrating the ability of the drug to enhance the effects of standard chemotherapeutics including 5-flurouracil, cisplatin and camptothecin in animal models when administered either systemically or orally.