Bad news is that the 10th post marketing Tysabri PML case was reported today. Another Ex-US case, 30 months on drug. This makes the 8th case Ex-US which definitely highlights some difference in Tysabri's use Ex-US (Europe) as the patients on Tysabri by time shown below.

Tysabri Uptake
Date Dosed Dosed
US EU
30-Jun-06 0 0
20-Oct-06 1,700 550
31-Dec-06 3,700 1,000
9-Feb-07 5,000 1,600
13-Apr-07 6,600 2,500
25-May-07 7,600 3,200
13-Jul-07 8,600 4,300
30-Sep-07 10,500 5,500
21-Dec-07 12,900 7,500
31-Mar-08 15,300 10,200
30-Jun-08 17,800 13,400

Chris

Ex-US Cases

Jul 30, 2008 - 17 months started Feb 07
Jul 31, 2008 - 14 months started May 07
Dec 10, 2008 - 26 months started Oct 06
Feb 5, 2009 - 12 months started Feb 08
Apr 15, 2009 - 31 months started Sep 06
Jun 10, 2009 - ~32 months started Nov 06
Jun 19, 2009 - ~31 months started Dec 06
Jun 23, 2009 - 30 months started Jan 07

6 of these 8 cases all started Tysabri from Sep 06 through Feb 07 (relatively small window with a small number of Ex-US patients).

As comparison, 6 out of about 1100 Ex-US patients who started Tysabri during the Sep 06 to Feb 07 period have developed PML. 0 out of the 3300 patients who started Tysabrio during this period developed PML. Seems to be a problem not just in Europe but maybe with this 1100 patient group.

As comparison, 6 out of about 1100 Ex-US patients who started Tysabri during the Sep 06 to Feb 07 period have developed PML. 0 out of the 3300 patients who started Tysabri in the US during this period developed PML. Seems to be a problem not just in Europe but maybe with this 1100 patient group.