Progen PI-88 trials proliferate

Australian biotech Progen Industries has won ethics approval to launch a Phase I human trial for its anti-cancer drug candidate PI-88 in conjunction with established chemotherapy agent Taxotere.

The trial is scheduled to commence next month at the University of Colorado Cancer Centre and will bring the number of PI-88 human trials currently running to four.

Researchers believe the combination of PI-88 with Taxotere may be more effective than using either treatment in isolation.

Toxicity trials have already been run on Taxotere and PI-88 independently of each other but the new Phase I trial needed to ensure that there are no unexpected side effects from the two in combination.

Taxotere is a cytotoxic drug which has a 'killer' effect on cancerous cells. PI-88 is expected to inhibit the growth of new blood vessels to cancerous tumours (angiogenesis) and reduce the spread of the disease (metastasis).

Because Taxotere reduces the bulk of the cancer while PI-88 prevents or delays its rate of recurrence, it is hoped that together they will pack a one-two punch, said Progen MD Lewis Lee.

Up to 25 volunteer patients with advanced malignancy suitable for treatment with Taxotere will receive the drug combination in the Colorado trial.

The same dosage of Taxotere will be concurrently accompanied by increasing levels of PI-88 administered as a subcutaneous injection once daily for four days a week.

PI-88 is being investigated for the treatment of various forms of cancer including solid tumours and blood cancers. At the moment, 29 patients are enrolled in standalone PI-88 clinical trials in the US (Phase I/II advanced cancers/melanoma), three Australian hospitals (Phase II multiple myeloma) and Taiwan (advanced cancers).

Recent trials have indicated that PI-88 is very well tolerated with minimal side effects, of which the most notable is minor bruising associated with the subcutaneous delivery method.

Brisbane-based Progen also operates a drug manufacturing facility and distributes products in Australia for international life sciences companies.