The last few weeks have been interesting on the neuroblastoma front. I have been part of several discussions on the future of MIBG therapy in neuroblastoma. Several of these discussions were in the research trenches but I also had the privilege of seeing Dr. Kate Matthay speak on the topic at Cook Children's the other night.
Secretly, I have always been a fan of MIBG therapy. I have seen many children with little hope for a cure have their lives saved in large part to this treatment. I know, without a doubt, that there are many children here today that would not have been without this treatment. For them, MIBG has been a miracle drug.
I am not alone with this insight.
There is a mounting army of survivors that can attest to the success of MIBG. Furthermore, there are many oncologists that have experienced these successes in children that they know they would likely have lost without the treatment. More and more are seeing the benefits of MIBG first hand.
As the research articles continue to flow from medical publications it is increasingly clear that MIBG will be an important part of neuroblastoma therapy in the future.
Many are aware of the toxicity of MIBG therapy. It is hard on counts and in many situations requires stem cell support. It is often this toxicity that has kept people from pursuing it as an option. However, now that the writing is on the wall that MIBG benefits may outweigh its side effects - especially for a certain group of ultra high risk patients - it should be a consideration. And, from what I am learning now, it looks as though it might be appropriate for all high risk patients.
As it stands now, MIBG therapy has a response rate of somewhere around 30 to 35%. That may not seem like a lot but, when you consider these response rates are based on the most heavily pretreated kiddos with the most resistant forms of the disease, that number starts to look better and better. Take this into consideration. Some of the best drugs we have for neuroblastoma, don't have a response rate as good as that. The old stand by, a combination of Topotecan and Cytoxan, has a response rate somewhere around 25% and our other relapse "go to" combination, Irinotecan and Temodar, only yields a response rate somewhere around 15%. Given those numbers, MIBG therapy begins to look really, really good - even considering the toxicity.
Make no mistake. MIBG is the most effective treatment we have in relapse when considering response rate. It is the toxicity cost that has to be weighed.
That is all fine and dandy but what really has intrigued me is the discussion of moving this treatment into up front therapy. Believe it or not, there is actually a study out of Europe that has looked at including MIBG at the very beginning of therapy. "Scarily toxic" you may say. However, "complete response" is what I have to say. It appears that MIBG may work even better in up front therapy and, as expected, response rates are even higher. Early data makes an argument that this could be the next big bump in survival.
Should MIBG therapy be one of the first things we do? Well, there are still some issues to work out. I think we need to get our stem cell collection completed before we hop into MIBG therapy to help reduce some of the secondary cancer risks. There are some logistical issues and other concerns as well. However, MIBG is on the horizon and it is closer than ever to being a mainstream treatment option for children with high risk disease.
Pilots are already offering MIBG in the up front window for ultra high risk kids and I would not be surprised to see MIBG as a component of a phase 3 trial as early as 2013.
Bottom line, if you have a child with high risk disease MIBG should be in the back of your mind. While today it is not for every child with neuroblastoma, it is certainly a strong option for a child with relapsed or refractory disease.
It is more ammo for your purpose gun.