Sticking with Tysabri, but Less Often May be Possible

There has been quite a bit of exciting news from the American Academy of Neurology (AAN) conference this year; a lot of it has been about new ways of looking at existing drugs. A study that has my particular interest is a look at natalizumab dosing and if it can be given less frequently and still be an effective multiple sclerosis disease modifying therapy treatment.

Before you scramble to figure out what drug that might be, this is the chemical name for the MS treatment Tysabri, the infusion drug used by so many of us. The recommended dosing for Tysabri, manufactured by Biogen, is once every 28 days. When I first started Tysabri, I was very conscious of when that four week mark would happen again and made sure my appointments were a s close as possible to that optimal date.

But sometimes life would get in the way and I would have to postpone my infusion treatment by a week or more. My neurologist was never overly concerned, and had even told me it appeared I could comfortably have my IV juice every six weeks. I try to stick to the every four week schedule but the few times I have pushed it further haven’t seemed to make any difference with my MS. Thanks to having a rather nasty virus on my last clinic date, my most recent Tysabri infusion was given at the six week mark and I noticed no difference.

Safety and Efficacy of Extended Dose Natalizumab in Multiple Sclerosis: An Ongoing Multicenter Study was done looking at records from 10 MS centers across the country, and it shows the dosing schedule of every 4 weeks is perhaps not so critical. The researchers from the NYU Langone MS Center took a retrospective look at over 2,000 people with MS and they found the dosing schedule for natalizumab could be flexible for 65% of the people they studied, and might be given as far apart as 8 weeks without a significant change to disease activity or drug efficacy. The remaining 35% of people on natalizumab might need to have treatments on the tighter schedule to hold off any disease activity.

“There remains much that is unknown about whether the drug will lose effectiveness if dosing is extended,” explains Dr. Zhovtis Ryerson, the lead researcher. “Our study showed treatment with natalizumab was safe for patients with similar efficacy reported as the standard dosing, potentially enabling patients to stay on effective MS medication at a reduced frequency of infusions and with lower risk of PML.'

"While the findings are encouraging, more research is needed to determine whether extending natalizumab dosing may reduce disability progression,” was noted by Dr. Ryerson in an NYU Langone press release.

This study was done independent of support of any of the MS pharmaceutical industry companies.

This reduced dosing schedule is appealing on several levels –

Taking natalizumab every 4 weeks equals 13 doses a year, and cutting that number in half means we might be decreasing the risk of contracting progressive multifocal leukoencephalopathy (PML). PML is a fairly rare brain disease but it can be disabling or even fatal if left untreated. There is a small but increased risk of PML with Tysabri over an extended period of years.

Reducing the medical costs of using the infusion clinic and the drug itself, would certainly make my health care insurance provider happy - each of my monthly visits costs in the $7-8,000 range. Cutting the number of visits in half would be a big savings on just one person – imagine if most of us on Tysabri scheduled our treatments this way, what that might add up to.

I’m fortunate that even though my veins are small and often difficult to start an IV line in, there are still places on my left arm or hand to put in the needles, but it is not unusual for it to take the nurse several attempts, and doing infusions less frequently would perhaps help to keep my limited spots to poke in better condition. It’s not unusual for people who get regular infusions of this drug or any other ongoing intravenous drugs such as cancer treatments, to have problems with lack of good veins to work with; being poked less often should mean better vein health.

Finally, making half as many trips to the clinic for my infusions, saving on gas and car expenses, time off work and all those other associated costs, would mean more money left in my bank account. I have to take a day off work and it would be nice to not be using all my sick days this way. Each time I go for my infusion it costs me real money in addition to the cost of the drug and clinic charges covered by my healthcare insurance.

These are significant reasons to motivate me to talk to my neurologist at our next visit about adjusting my Tysabri infusion schedule. For me personally, this study may be the best news I’ve heard in a long time about treating MS.

Wishing you well,


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This article represents the opinions, thoughts, and experiences of the author; none of this content has been paid for by any advertiser. The team does not recommend or endorse any products or treatments discussed herein. Learn more about how we maintain editorial integrity here.

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