Avastin approval is great news for biotech, say pundits

Last week's thumbs-up by the US Food and Drug Administration for Genentech's anti-angiogenesis drug Avastin (bevacizumab) for the treatment of metastatic colorectal cancer has widespread implications both for cancer therapy and biotechnology in general, according to industry observers.

"Avastin was last year's number one event and it will be this year's number one event -- that's how significant it is," said analyst David Blake, co-editor of Bioshares. "It's really brought the sector forward."

Avastin was approved as a first-line treatment option, rather than as a drug of last resort, after exhibiting significant improvements in the mean survival times of patients with metastatic colorectal cancer when administered in combination with standard first-line treatment regimens. Analysts expect the drug to eventually bring in US$2 billion per year or more.

Blake said that the approval of Avastin was a good example of all the stakeholders involved in the process getting it right, from the drug developers to the FDA.

New fast-track systems at the FDA allowed the company to submit documents on a rolling basis to facilitate the review process, and the drug gained approval within six months of Genentech submitting the final application.

Just as importantly, the approval of Avastin was the first in a new class of cancer therapeutics targeting angiogenesis, or the formation of new blood vessels -- an important process for tumour growth first identified a couple of decades ago. The monoclonal antibody-based drug targets a major growth factor involved in the process, known as vascular endothelial growth factor, or VEGF, suppressing angiogenesis, discovered by Genentech scientists in 1989.

"Those of us who have had programs in angiogenesis had it clearly in our minds that it was a great target for cancer, but before the approval of Avastin, there was no marketed product to show the benefits of targeting angiogenesis," said Dr Deborah Rathjen, CEO of Bionomics, one of several companies in Australia involved in anti-angiogenesis R&D.

Brisbane-based Progen is probably the Australian company with the most advanced angiogenesis inhibitor -- its lead compound PI-88 is being tested in a series of Phase II clinical trials. Early results have been promising -- 39 per cent of patients with relapsed or refractory multiple myeloma demonstrated stabilisation of disease after treatment with PI-88.

Current and future Phase II trials are looking at the effect of PI-88 as a single agent treatment for advanced melanoma, in combination with docetaxel in patients with advanced non-small-cell lung cancer and as an adjuvant single-agent therapy in post-operative liver cancer patients. Progen's managing director Lewis Lee said the approval of Avastin provided significant validation of the company's approach.

A third Australian company, Alchemia, is also working on an anti-angiogenesis approach, announcing recently that it had identified a promising lead compound with anti-angiogenic properties.

From a clinical perspective, the news of the approval is very exciting, said Assoc Prof Mark Rosenthal, director of Melbourne-based clinical trials organisation Cancer Trials Australia. "It's another incremental improvement in cancer care -- in this instance a significant improvement," he said.