Hi, my name is Dr. Sanjay Sharma and I am a retina specialist and health policy researcher at Queen’s University in Kingston Ontario.
I want to outline the policy issues surrounding the heated debate that is happening now regarding the potential to save the health care system millions of dollars per year. The issues surround the use of two drugs called Lucentis and Avastin that are used to treat one type of age-related macular degeneration.
15 years ago, scientists discovered that a molecule called VEGF played a key role in the development of macular degeneration. Luckily, a company called Genentech already had an anti-VEGF antibody called Avastin which had been approved to treat colorectal cancer. But scientists worried that the Avastin molecule was too large to work properly in the eye, and so Genentech designed another anti-VEGF molecule called Lucentis that was one-third the size. They did it by splitting the Avastin molecule and getting rid of the part of the molecule that attracts inflammation.
When Lucentis was developed, Genentech immediately began the long process of conducting clinical trials to get it approved for treatment of macular degeneration. This process takes many years and many different study types and can cost over a $billion.
But because our patients were going blind as we waited for the results of Lucentis, some of us started using Avastin through injection into the eye even though is wasn’t approved for macular degeneration… and we had good results.
In 2006, the Lucentis results were published in the NEJM. They showed that Lucentis was able to prevent visual loss in 95% of patients and actually bring back significant vision for 1 in 3 patients- which really was incredible. So based on these results, most regulatory bodies like the FDA and Health Canada quickly approved Lucentis for wet macular degeneration.
Because of the interest in these 2 drugs, several studies were also started to compare Avastin head to head with Lucentis.
One of these studies, the CATT study – which was paid for by the National Institute of Health - showed that both drugs were equally effective in treating age-related macular degeneration. Both drugs had tremendous benefit for patients.
But, this same study raised concerns that Avastin was not as safe at Lucentis. The study showed a “number needed to harm” of 12 in favor of Lucentis. What this means is that for every 12 patients treated with Avastin instead of Lucentis, one would develop a bad systemic outcome. And that is a pretty scary number.
Here at Queen’s University, we studied more than 1,500 of our patients who received either drug. We found that patients who got an eye injection with Avastin were 12 times more likely to develop serious inflammation in the eye. We also noticed a trend towards the possibility of patients developing a stroke within 30 days of getting an eye injection with Avastin. In our study this was not statistically significant but this concern was also noted in a large study of over 40,000 patients in the US which showed a 22% higher risk of stroke for those using Avastin. These are significant results.
Despite the safety concerns raised by these studies there is an ongoing policy debate over whether to allow the use of Lucentis over Avastin. Some health policy-makers want us to stop using Lucentis altogether. Why?
What it really comes down to is the huge difference in drug cost. Lucentis costs $1,700 per injection and Avastin retails for $100. And that is definitely a big difference.
But I don’t think that we can just consider the dollar value of the medicine alone. We need to consider other costs too. For example the cost of dealing with adverse events like severe eye inflammation or stroke. And most importantly we need to think about the human cost of living with these adverse events.
These recent safety studies need to be brought forward and made part of the debate. But based on what we have seen to date, in the end the biggest question that we may have to ask ourselves is:
What value should be put on safety?