"We were all extremely surprised with the results," Robyn Ward, a University of NSW professor, tells The Age. "We just couldn't believe that people weren't monitoring the safety of what was still a very, very new drug."
The study, which reviewed 1,469 women who received the med between 2001 and 2005 and was published in the Journal of Clinical Oncology, found that some clinicians had ignored the warning labels altogether. Thirty-three women received the drug in combination with a type of chemotherapy known to heighten the risk of heart failure.
In all, 22 per cent of the women received Herceptin "off-label", or as part of a combined therapy not approved by the Therapeutic Goods Administration. Ward says the results highlighted how important it is to monitor all new drugs, especially those that had been fast-tracked.
There are "emotional issues around things like cancer drugs and often there's an incentive to release them as soon as any hint of efficacy is seen," she says. "Herceptin is characteristic of a lot of these drugs: we only hear about the benefits and rarely about their downside or cost."
Melbourne oncologist Ian Haines says patients needed to be kept up to date with findings about the risks of drugs and that Australia has a duty to scrutinize safety of new meds. "The longer we go with Herceptin, the more long-term heart problems we're seeing. People (may) have died of heart disease rather than of their breast cancer...Australia has a unique opportunity because of our database of information."
The University of NSW study also found that, with dosage based on a patient's weight - about $21 million of taxpayer money - had been wasted because Herceptin was only sold in 150-millilitre vials. That'is nearly a quarter of all Herceptin dispensed over the period. At a cost of about $45,000 US per patient per year, Professor Ward says pressure had to be put on companies such as Roche, which makes Herceptin, to provide smaller doses.
Herceptin was subsidised in 2001 for women with late-stage breast cancer after it was shown to delay the spread of the disease. That was despite the advice of the Pharmaceutical Benefits Advisory Committee that the drug had not proven its safety or cost-effectiveness. In October last year, women with early-stage breast cancer were also allowed to start receiving Herceptin, as long as they tested positive for the relevant gene mutation that the drug targets.