#ACTRIMS2018 – Extending Tysabri Treatment Intervals May Reduce PML Risk, TOUCH Registry Data Suggest

#ACTRIMS2018 – Extending Tysabri Treatment Intervals May Reduce PML Risk, TOUCH Registry Data Suggest

Extending the dosing periods of Tysabri (natalizumab) treatment may help reduce the risk of progressive multifocal leukoencephalopathy, or PML, in multiple sclerosis (MS) patients infected with the JC virus, a study suggests.

The study, “Natalizumab Extended Interval Dosing Is Associated with a Reduction in Progressive Multifocal Leukoencephalopathy Risk in the Touch Registry,” was recently presented at the third annual Americas Committee for Treatment and Research in Multiple Sclerosis (ACTRIMS) Forum 2018, held Feb. 1-3 at the Hilton San Diego Bayfront in San Diego, California.

Tysabri — an approved therapy for relapsing forms of MS marketed by Biogen — administered as a 300 mg intravenous dose every four weeks is known to be linked to a higher risk of PML, a rare viral infection in the brain caused by the John Cunningham (JC) virus.

Extending the dosing intervals between Tysabri treatments is sometimes practiced, especially in patients at high risk of developing PML, but the outcome of this strategy in terms of PML risk remains inconclusive.

In this study, researchers used a U.S. risk evaluation and mitigation program called TOUCH Prescribing Program to assess whether extending the interval of Tysabri dosing could be associated with a reduced PML risk compared with the standard four-week interval. The TOUCH program had data from 90,038 MS patientsas of June 1, 2017.

The team analyzed data from patients who tested positive for anti–JC virus antibodies, and defined three different standard and extended dosage intervals: from three to five weeks for standard treatment, and from five to 12 weeks for extended interval dosing. Patients with dosing intervals of more than 12 weeks or less than three weeks were excluded.

The average dosing interval was 29 days for standard treatment and 36 days for the extended interval program, with a median exposure of 44 and 59 months, respectively. The majority of patients followed a standard program for more than two years before undergoing the extended interval dosing program.

The results showed that the extended dosing program was associated with a significant reduction in the risk of developing PML, compared with the standard regimen in anti-JCV-antibody-positive patients.

However, whether Tysabri maintained the same effectiveness as in the standard regimen was not evaluated, because the TOUCH program does not collect effectiveness data.

As such, “additional studies are needed to establish whether the effectiveness of natalizumab is maintained with EID 
[extended interval dosing],” the team concluded.


  1. Brian Fletcher says:

    My neuro team and I have known I carry the JC virus since I started on Tysabri on 2/1/08. Last January, we switched from four to six weeks for my infusion frequency, and have been getting MRI’s done every 3-4 months (started that about a year and a half prior to the dosing change, as I’m considered high risk). I just had my last Ty dose 12/26/17, and am in the process of starting Ocrevus.

    As scary as the possibility of PML has been, I’ve been relapse-free for the period I’ve been on Tysabri. I actually wish I’d been able to start it sooner… I the period between Biogen voluntarily pulling the drug and it being reintroduced with the TOUCH protocols, I suffered a flare that has left me in a wheelchair. The benefits of being relapse-free have outweighed the risks, as scary as they are.

  2. Shirley says:

    I too was on Tysabri for 4 years and JC positive.
    Somehow I dread the possibility of cancer from the new drug rather than PML

  3. Becky says:

    Diagnosed with RRMS 1992 and did the steroids and then the other DMT’s that came out during that time and covered my injection sites with sterile abscesses and huge crater scars.I have been on Tysabri since the FDA put it back on the market.It has been a great drug for me. I have been gaining abilities the entire time that I have been on it.I can almost run and jump(2 of my improvement markers). My last JCV test was a straight Positive for JCV antibodies(from an Indeterminate status for 5 years). The medicAl information says I should go off the Tysabri. I am hesitant to do so given my good response to it. I was forced to go off Tysabri for 3 months about 4 years ago after I was bitten by a bat and needed Rabies Treatments.I did suffer a bit physically but it was not as bad as my pre-tysabri time. Does anyone know at which point, and what degree of positive, a person should let themselves get to before they must go off Tysabri? I know it is a personal and medical decision and everyone has their own parameters of guts and fears.I am getting a bit nervous.

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