from the age

Cancer drug trial exceeds expectations
March 14, 2007 - 1:29PM

Biotech company Prima BioMed says a trial of its experimental ovarian cancer treatment has "exceeded expectations", paving the way for further testing.

Prima BioMed said the phase IIa trial of 21 patients with late stage ovarian cancer showed four had a positive clinical response or stabilisation of the disease, meeting its target of a 15 per cent success rate.

The company is now planning the next stage of trials of the CVac treatment, involving 100 to 200 patients, due to begin over the next 12 months.

The phase IIa trials of the drug were taken in Melbourne's Austin Hospital, with patients with incurable advanced ovarian cancer given a course of seven injections over a 12-month period.

Associate Professor Paul Mitchell, director of cancer services at Austin Hospital and principle investigating oncologist, said the results demonstrated a "clear benefit in patients with progressive ovarian cancer".

"It suggests that CVac is a promising new approach for ovarian cancer and warrants further clinical investigation," he said.

"As far as we're concerned we've got evidence that for some patients with incurable ovarian cancer, the CVac vaccine has proven to be an effective treatment with minimal side effects.

"It's been very promising."

CVac is a cell therapy that takes an ovarian cancer sufferer's dendritic cells - a rare type of white blood cell that induces immunity - primes or boosts them with the CVac vaccine, before they're reinjected into the patient.

Exposure to CVac, a combination of a protein and a sugar which is commonly on the surface of cancer cells, is designed to train the cells recognise the cancer, so they then target the disease when reintroduced to the body.

Prima BioMed chief scientific officer Associate Professor Bruce Loveland was also pleased by the results.

"These results indicate the potential of dendritic cell therapy and the CVac approach to harness the immune system to intervene in tumour growth, even in patients with advanced disease," he said.

Prima BioMed is now planning for the next stage of CVac's development, a controlled Phase IIb trial in patients in Australia and New Zealand.

But unlike earlier trials, which have treated women with advanced stages of ovarian cancer, the next trial will test the effects on women in earlier stages of the disease.

"The question now is whether we can get greater effect by treating women with ovarian cancer early in the course of their disease," Assoc Prof Mitchell said.

"We're interested in terms of how well the vaccine will perform where we can make a substantial improvement in terms of delay of the cancer returning, and hopefully some benefits for survival."

The results of the next trial are expected to be released in three years.

If successful, the company will then move to phase III trials in the United States, and seek US Food and Drug Administration approval.

Shares in the Melbourne-based Prima BioMed were up 1.3 cents, or 28.3 per cent, at 5.9 cents at 1235 AEDT after hitting a morning high of 6.5 cents.

© 2007 AAP