Biotech Values

[DewDiligence]

Tysabri’s FDA label hasn’t been updated since Oct 2008. This is what it says about the PML risk:

http://www.accessdata.fda.gov/drugsatfda_docs/label/2008/125104s0067lbl.pdf

The absolute risk for PML in patients treated with TYSABRI cannot be precisely estimated, and factors that might increase an individual patient’s risk for PML have not been identified. There are no known interventions that can reliably prevent PML or adequately treat PML if it occurs. It is not known whether early detection of PML and discontinuation of TYSABRI will mitigate the disease. There is limited experience beyond two years of treatment. The relationship between the risk of PML and the duration of treatment is unknown, but most cases of PML were in patients who received more than one year of treatment.