The nerve-wracking two days of Tysabri's Food and Drug Administration Review Meeting has arrived. A Reuters report allows us the following early insights:
- Tysabri's sponsors, Biogen and Elan, have obviously asked the FDA to allow Tysabri back onto the market.
- They have proposed restrictions including creating a mandatory patient registry to track side effects (Accutane is an example of a drug with a registry), and providing the drug only to MS patients that do not have "weakened" (definition of 'weakened' not clear from our sources) immune systems *and are not taking other MS drugs* (Interesting, as this closes off entirely the Biogen-promoted Avonex+Tysabri combo that in the trials was associated with PML in MS patients)
- In another potentially surprising move, the companies actually proposed the infamous "black box" warning be applied to Tysabri, indicating in the strongest terms available that patients could develop the devastating illness we have all unfortunately become familiar with: Progressive Multifocal Leukoencephalopathy, or PML.
- Biogen's Executive Vice President of Development, Dr. Burt Adelman, says these proposed steps "will enable us to proactively detect new safety signals."
- In very blunt terms, Dr. Russell Katz, director of the FDA's Neurology products division, said that "We fully expect additional cases of PML, many likely to be fatal." It is unclear to us (thisisms) where this assertion is coming from, given PML was never seen in MS patients undergoing monotherapy (Tysabri only).
Though anything that has something to do with Tysabri is inherently intriguing, what strikes us is that the companies are pitching Tysabri as a medicine only for a certain subsegment of MS'ers, and willingly branding it a potentially dangerous therapy with the black box warning. This approach, contrasted with a more cavalier one that might e.g., say, 'it's better than what is available today, and the risk is worth it,' should be appealing to the FDA that is in the unsavory position of balancing unknown and potentially lethal risk with a large benefit that the MS community is clamoring for.
As always, stay tuned...
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