PML in MSer on Fingolimod - no report of prior immunosuppression or Natalizumab treatment

#MSResearch PML case with Gilenya

"Novartis confirms that it has received a report of a PML (progressive multifocal leukoencephalopathy) case. The patient had been receiving Gilenya® (fingolimod) for the treatment of relapsing MS (RMS) for more than 4 years. The diagnosis was made based on MRI findings and additional tests for JC (John Cunningham) virus. The patient is currently doing well. The case has been reported to Health Authorities. Patient safety is of paramount importance to Novartis, and we continue to monitor all aspects of patient safety on an ongoing basis. The positive benefit-risk profile of Gilenya in relapsing MS is based on experience with 114,000 patients treated with Gilenya and more than 195,000 patient years and accumulation of real-world efficacy and safety data."

It is important to put this into perspective. This is so far a rare occurrence based on experience with 114,000 patients treated with fingolimod, more than 195,000 patient years as well as related real-world efficacy and safety data. 

The logic of fingolimod was a step down from Tysabri that traps cells in the blood, so they can't get in the brain and so do not protect against the virus in the brain...when fingolimod traps most cells in the lymph glands so they can't get in the blood, so they don't get in the brain to protect against the virus. One may suspect that there will be leucopaenia, but we we will have to wait for further details. There was no indication on the website that this person had had natalizumab/immunosuppression

Novartis will claim that Gilenya does not affect the anti-viral arm, but one of the side effects of the drug can be poorly controlled viral infections. Nevertheless, the risks of Tysabri and Gilenya are clearly not the same. There is a thought that Tysabri is part of the problem that causes release of JC virus from the bone marrow.

This is another day of concern for people with MS, however it shows that if you persistently suppress the immune system PML is going to be an ongoing risk; this is one of the reasons why induction therapies have merit: after the initial period of immune suppression the immune system is drug free to fight viral attacks.

CoI: multiple

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