What we know:

1) The patient is suspected to have PML, but the diagnosis has not been confirmed.

2) The patient is not dead, as erroneously reported in the Boston Globe. "The patient that the Globe referenced is definitely alive," said Biogen spokeswoman Amy Brockelman.

3) The FDA is aware of this case. "The case is being reviewed," FDA spokeswoman Lenore Gelb said.

4) The patient was apparently on a combination of Avonex and Tysabri. We already know this combination can induce PML, so an additional case should not by itself be considered shocking. In fact, in a perverse fashion the more PML cases in this sub-class, the better the data set to understand how and why PML can develop. Our hearts of course go out to the afflicted patient and their family, but as with any therapy that has potentially dangerous side effects, information must be gleaned from tragedy for the common good.

5) People jumping to conclusions about the negative implications of a fourth case on the availability of Tysabri should remember that the CEO of Elan last week said that Tysabri's return was quite likely (see previous article). Given that the source for the Boston Globe report was publicly available data, it seems highly doubtful that he was not aware of the existence of this case when he made his comments.

Likewise, Tysabri monotherapy has had no reports of PML, and if the link between co-administration of Avonex and Tysabri can be solidified, the task of determining the all-important PML-Tysabri risk seems to become easier, not harder. That being said, the additional case highlights the uncertainty around Tysabri's final outcome as the safety review of all patients continues.

Please click "read more" to obtain links to selected articles on this issue.

Links:

Original Boston Globe Article

Elan hit by report of fourth Tysabri-related illness

Update: The Wall Street Journal is reporting additional details tonight regarding the 4th PML case.

It was disclosed through the FDA's adverse-event reporting system (MedWatch) on April 18 by an unidentified health professional. The report explains that the patient is a 48-year-old woman hospitalized with multiple illnesses (not specified in article), among them PML. The patient was taking Avonex, and "two other MS drugs from different manufacturers."

It is not clear from the WSJ article if the "two other drugs" (either Copaxone, Novantrone, or Betaseron-- Rebif is an IFN-a similar to Avonex) were being co-administered.