Analysis of Biogen’s Touch program which tracks about 90,000 patients using Tysabri reported 15 cases of PML in patients who were on extended dosing intervals.
Yesterday, the director at an MS Clinic told me that 6 of the 15 cases were of patients who had been on extended dosing but had gone back to standard dosing of 4 weeks. The average interval on extended dosing was 6 weeks, according to that neurologist.
Biogen’s TOUCH program data was interpreted as follows:
Three separate definitions of standard-interval dosing (SID) and extended-interval dosing (EID) were analyzed from the TOUCH program tracking Tysabri patients.
The first group analysis involved those who had fewer than 15 infusions in the last 18 months compared to those who had more than 15 infusions the last 18 months. There were 3 PML cases in 1,988 on extended dosing in this group and 89 cases of PML in 13,132 on standard dosing.
The second group analysis defined extended dosing as anyone who had ever extended dosing for at least 6 months at any time during their treatment history with Tysabri. In this group there were 12 PML cases in 3,331 on EID and 71 cases of PML in 15,424 on SID. Remember, some of the 12 cases of PML in EID had gone back to SID. Possibly, because MS was not sufficiently suppressed on EID.
The third group analysis defined extended dosing as fewer than 10 doses per year and standard dosing as more than 10 doses per year. There were zero cases in 815 patients in this extended dosing group having less than 10 infusions per year compared to 96 cases of PML in 23,168 in the standard dosing group having more than 10 infusions per year.
Sadly, the very bad news is that there remains a risk of PML even with EID.
The good news is that PML risk is greatly reduced by extending time between doses.
https://www.mdedge.com/neurologyrevi...mab-associated
Yesterday, the director at an MS Clinic told me that 6 of the 15 cases were of patients who had been on extended dosing but had gone back to standard dosing of 4 weeks. The average interval on extended dosing was 6 weeks, according to that neurologist.
Biogen’s TOUCH program data was interpreted as follows:
Three separate definitions of standard-interval dosing (SID) and extended-interval dosing (EID) were analyzed from the TOUCH program tracking Tysabri patients.
The first group analysis involved those who had fewer than 15 infusions in the last 18 months compared to those who had more than 15 infusions the last 18 months. There were 3 PML cases in 1,988 on extended dosing in this group and 89 cases of PML in 13,132 on standard dosing.
The second group analysis defined extended dosing as anyone who had ever extended dosing for at least 6 months at any time during their treatment history with Tysabri. In this group there were 12 PML cases in 3,331 on EID and 71 cases of PML in 15,424 on SID. Remember, some of the 12 cases of PML in EID had gone back to SID. Possibly, because MS was not sufficiently suppressed on EID.
The third group analysis defined extended dosing as fewer than 10 doses per year and standard dosing as more than 10 doses per year. There were zero cases in 815 patients in this extended dosing group having less than 10 infusions per year compared to 96 cases of PML in 23,168 in the standard dosing group having more than 10 infusions per year.
Sadly, the very bad news is that there remains a risk of PML even with EID.
The good news is that PML risk is greatly reduced by extending time between doses.
https://www.mdedge.com/neurologyrevi...mab-associated
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