Even under close evaluation, PML remains a rare disease. But as we alter the immune system, we need to understand what unintended effects it might have. |
Statistically then, the risk is approximately 1 in 1,000, which is substantially higher than in the normal population. We're also careful to say we do not know what the risk is for individuals with long-term use of the drug. |
This study was designed to address a critical, immediate need for patient safety in the people who participated in clinical trials of this drug. |
We concluded that at this particular time there is no evidence that there are more PML cases. |
We had to assess who else might be at risk. |
We have found no evidence of additional cases of PML. |