Trying to decide on new medicine to take. Right now I believe I have narrowed it down to Tecfidera or Tysabri.
My JCV came back as 0.23 positive. I am told that is considered on the low side. I used to take Avonex for about 3-4 years, but stopped about 18 months ago.
My history is this:
I have had about 2 relapses in 9 years since the original 'pain' after knee surgery in 2005 - pain on right side of face/head, left leg, some other 'minor' things possibly.
I understand Tecfidera to be about 50% effective, and Tysabri to be 98% effective. My concern is how long you can you be on Tysabri? I looked at Dr. Kinkle's flowchart (SEE FLOWCHART), and it looks like people on Tysabri for 4+ years have much greater risk of developing PML. It was my understanding that a lot of people in my position, early diagnoses with good mobility etc., are starting to take Tysabri where as a few years ago it wasn't considered unless it was an extreme case. I am confused as to how to go about my decision on which is best for me in my current situation?
You are asking the correct questions and beginning to think through this decision rationally, so let me give you a little help. While I still do not have enough information to provide the individual advice you are looking for, I can help refine the answers to some of the points you raise:
- A JCV index of 0.23 is considered very low. To my knowledge, there has not been a case of PML yet with an index below 0.4 so this is virtually the same as being JCV antibody negative. Now remember, there is still about a 2% per year risk of your index value rising significantly. This is actually a guess since the data is somewhat old and refers to the risk of a patient going from JCV antibody negative to positive at any index value. I suspect the conversion risk from JCV negative or low positive to high positive (> 1.5) is probably less than 2% per year.
- The risk of PML does increase significantly over time but only in those who are JCV antibody positive in higher titers; PML is rare in everyone for the first year or two of treatment. The figure you are referring to lumps everyone with a JCV index < 0.9 into one category (you are 0.23) ; in this group the risk rises to 1 in 2500 after 3 years which is still a really small risk.
- I would not say that Tysabri is 98% effective; I would say that people on Tysabri who are completely stable (by clinical and MRI criteria) after one year of therapy have a greater than 90% chance of remaining stable, although this figure has a number of caveats to remember; namely, it only applies to relapsing remitting MS patients of the type who participated in the Phase III studies.
- Tecfidera is a good drug but we do not yet have a sense of its overall effectiveness in real world populations, only in those who participate in clinical trials.
I hope this helps.
-Rip Kinkel, MD