Psiron's cancer therapy passes first clinical tests

Sydney virotherapy developer Psiron (ASX:PSX) reported this week that two end-stage melanoma patients have shown no adverse effects from the first human test its of its oncolytic virus therapy,

Ass Prof Darren Shafren, of the University of Newcastle, told the third international meeting on Replicating Oncolytic Virus Therapeutics in Banff, Canada, last Friday, that the two patients, with multiple, metastatic melanoma tumours, were injected with a single dose of Coxsackie Virus A21 (CVA21)

The two Australian patients were enrolled under special access scheme (SAS) provisions, which allow developmental therapies in tested in end-stage cancer patients for whom conventional cancer therapies have failed.

The virus was injected directly into several tumours in both patients. Surgeons subsequently removed the treated tumours, along with other, untreated tumours that served as controls.

Shafren told the conference his research team observed no systemic toxicity or localised inflammation, while the patients' blood biochemistry and liver-enzyme levels remained unchanged.

The findings indicated that the treatment was well tolerated. Previous pre-clinical trials in mice showed that injected CVA21 viruses specifically target and destroy melanoma cells.

The injected virus replicates rapidly for a brief period, inducing both lysis and apoptosis of infected melanoma cells. The virus attaches to an intracellular adhesion molecule, ICAM-1, and another molecule called decay accelerating factor (DAF) on the surface of the cells.

Shafren's team discovered the melanoma-cell killing properties of CVA21 and licensed the IP to Psiron. His team has also licensed a second virus, Echovirus Type 1 (EV1) that, in mice, is a potent killer of ovarian cancer cells.

Psiron CEO Julie Nutting said today the company plans to begin a Phase 1 clinical trial in volunteers this year.