If only it were that simple, Chris.

Apparently there has been approx. one “unconfirmed” case of PML per month reported since the reintroduction of Tysabri, but in every public discussion/corporate Q&A session I've read, Biogen has flatly refused to discuss these cases.

Unfortunately, the neurological symptoms associated to PML may mimic our MS symptoms, and MRI changes (due to PML) may be so subtle that it may be difficult to differentiate PML from MS lesions, without actually doing a biopsy. JC levels may remain below the level of detection at the initiation of a CNS infection, so that even if someone does not initially “prove” to have PML, it doesn’t mean they didn't get it.

There is even some question as to whether one or more of the cases that IS confirmed, actually had/has PML. I just don’t think it is that cut and dry.

It would seem to me, however, that before an adverse event for suspected PML is lodged, the patients’ would have undergone testing, and the results would strongly indicative of PML. Often the cases can not be confirmed (or ruled out) at that point though, so my specific question is “what is the established/required PML confirmation protocol”?

It can take weeks to even months before the JC levels reach detection level for PML, however in the case of patients highly suspected for PML, neurologists are instructed to immediately cease Tysabri and consider treatment with plasma. I trust that they are following this procedure, and chances are this is how “suspected” cases are born in the AE system.

But what then?

It is my understanding that the discretion to cease treatment, use plasma (per the PLEX protocol), as well as for further follow-up with the patient then lies with his physician. But what are the physicians’ expressed responsibilities for follow-up on his patients? Is he mandated to do further testing of JC levels to ultimately confirm/rule out PML?

And, could the use of plasma affect follow-up JC results, often required for confirmation of PML?

What is Biogen’s responsibility in all this? Do they have ultimate responsibility to confirm PML, or does the physician? From what I can tell of the 8-K filings for the European cases, Biogen seemed completely in the dark about the suspected PML cases, up until the point that PML was confirmed by the patient’s physician . . . So, my guess is that perhaps they don’t have any obligation for independent evaluation of every suspected case that is reported.

As far as deaths, what is a physician’s obligation to rule in or out PML for all patients who were on Tysabri? How long might it take to receive these results . . . we still don’t even have confirmation on the cause of death for that US woman who died in early Dec with PML.

What I want to know is what is the specific audit process for suspected cases of PML? Is it the responsibility of the physician to prove PML? Really, what purpose would it serve HIM to do that . . . it’s not like anything at all can be done to treat or manage the disease at that point . . .?

What if the physician doesn’t do follow-up . . . does this just become another case of “unconfirmed PML”? It wouldn’t be good that a physician not do this due diligence . . . but who/what entity is monitoring to ensure they are?

The bottom line is “who’s responsibility is it to thoroughly investigate every reported case of suspected PML”; Biogen’s? The FDA? The physician’s? The patient’s? The patient's lawyer?

I haven’t found documented answers to these questions, but if you have Chris, I would appreciate a link.

Cherie