citi: Biogen Idec Inc (BIIB)
More PML Cases Than Expected – True Rate Still Unclear
? Conclusion(s) — EMEA's decision to review risks/benefits of Tysabri is not
surprising, but the large number of PML cases that were not previously
disclosed (23 cases in total vs. street expectations of 13-17 cases and BIIB's
last update of 11 cases in late July) was unexpected. We believe this is an
incremental negative for Biogen Idec, and will likely lead to a label update in
the US/EU underscoring the higher risk of PML with longer treatment duration.
More so, this raises the potential for docs to institute treatment holidays.
Finally, EMEA may institute more stringent risk mgt program such more similar
to the TOUCH in the US. Currently, there is no risk mgt program in Europe for
Tysabri, possibly explaining why there are more PML cases in Europe than in
the U.S. We would remain on the sidelines. Our top ideas for remainder of the
year are Celgene (Buy) and Gilead (Buy).
? Figuring out the Rate of PML — While there is no information currently on how
long these pts have been on therapy, assuming that they all have been on
Tysabri for >12 mos (all previous 11 cases were in pts with >12 mos exposure)
the rate is 0.668/1,000. If all new cases were in pts with >24 mos exposure (7
previously reported and 12 new cases) the rate would be an alarming
1.42/1000, which is above current label rates. To remain within the 1/1000
rate, a maximum of 6 out of the 12 new cases could have been in pts with >24
mos exposure.
? Impact on Biogen Idec — It is unclear at the moment if EMEA will take action
on Tysabri based on these new disclosed PML rates. We believe the risk/reward
for Tysabri may still be deemed to be positive based on physicians' comments.
However, if the rate creeps substantially above 1/1000, it is possible that
regulatory agencies may consider more severe measures. We do expect,
however, both the EU and U.S. label to be revised to include this new
information and some language stating that the risk of PML increases with
Tysabri exposure. |
