ASCO 2011 Annual Meeting, 3—7 June 2011, Chicago
New melanoma drug gives 63 percent reduction in risk of death compared to dacarbazine
Dr Paul Chapman – Memorial Sloan-Kettering Cancer Center
What we’re presenting are the results of a phase III trial in patients with metastatic melanoma whose tumours have a mutation in a gene called BRAF. These patients had never been previously treated and they were randomised to receive either a standard chemotherapy called dacarbazine or this experimental drug called vemurafenib which is given as a pill twice a day and is designed to block this mutation in BRAF. The results were quite astounding that in an early look at the data we found that the patients who were getting vemurafenib had a 63% decreased risk of death and a 72% decreased risk in progression. As a result of that we have stopped the trial and allowed the dacarbazine patients to cross over to the vemurafenib arm so now that everyone has an opportunity to get this drug.
What proportion of melanoma patients does this apply to?
About half the patients have this mutation so it’s a large number of people.
What about side effects?
The most common side effects with this experimental drug were skin rash, joint pain, inflammation in the liver and patients developed a non-melanoma skin tumour, either a squamous cell cancer or benign tumours like warts. That happened in about 18% of patients but for the other side effects that I mentioned, most of them were pretty mild, less than 10% were what we call grade 3 or 4 and they were mostly easy to deal with.
How do you see this impacting the clinic?
If this gets approved this will be another, a second drug, available that improves survival in melanoma and this is a fantastic situation for our patients. So now we’ll have to figure out how we’re going to use ipilimumab versus this drug and it’s not really either/or, a lot of patients will get one and, if it doesn’t help them, will get the second drug.
Is there potential for combination with other therapies?
We’re exploring combinations now, we’re about to start a phase I trial combining these two drugs to make sure that it’s safe to combine them and to make sure that one drug doesn’t interfere with another drug. And if it turns out to be OK to combine them, we will go ahead with a bigger trial, hoping to see an increased rate of complete responses.
