I did not find any point about the CRABs.
"Patients treated with an immunosuppressant (IS) prior to receiving TYSABRI have an increased risk of PML; IS use includes agents such as mitoxantrone, azathioprine, methotrexate,cyclophosphamide, mycophenolate and cladribine. This increased risk appears to be independent of TYSABRI treatment duration and is based on the fact that 46% of TYSABRI patients with PML had been treated with an IS prior to receiving TYSABRI. From the TYGRIS Observational Study, it is estimated that 20% of TYSABRI-treated patients (13% in US and 24% in EU) have been treated with an IS prior to receiving TYSABRI. Hence, there appears to be a disproportionate representation of prior IS use in the patients with PML compared to the TYSABRI-treated population overall,
The data indicate that patients with prior IS use have ~4-fold greater risk of PML compared with patients without prior IS use.Patients with prior IS use have ~2-3 fold greater risk of PML compared with the overall TYSABRI-treated population, and patients without prior IS use have ~50% lower risk of PML compared with the overall TYSABRI-treated population. The US TYSABRI prescribing information now reflects these observations. Nevertheless, the overall worldwide incidence of PML associated with TYSABRI therapy since reintroduction remains generally consistent with the rate previously observed in clinical trials (1). Databeyond 3 years are limited."
Al Sandrock, Senior Vice President of Neurology Research & Development, Biogen
After a thorough evaluation of our post-marketing surveillance data, we have concluded that the risk of PML is increased in patients have been treated with an immunosuppressant prior to receiving TYSABRI.
This increased risk appears to be independent of treatment duration and there was a broad range in the time interval between the discontinuation of the prior immunosuppressant and the TYSABRI initiation. Recall that the original label had warned that patients receiving TYSABRI should not be treated with concomitant immunosuppressants. We have added an additional warning about the prior use of these drugs to the existing warning.
Based on data from the TYGRIS observational study, only 13% of US patients and 24% of ex-US patients have had prior immunosuppressant use, whereas about half of the PML cases had previously received these drugs. Thus, there was a disproportionately higher representation of prior immunosuppressant use in the PML cases. The new label changes were posted online as of July 15th. Overall, we continue to learn more about factors associated with the risk of PML and we’re looking forward to providing data to the MS community to help with their decision-making for treatment choices.
How does that get communicated to physicians?
In terms of communication, it’s on the – it’s online in the new label. It’s also included in our monthly update that that physicians who are – who have – who are licensed physicians can go into our website and look at. And, of course, we hand these out on request to physicians. So that’s what we do. I don’t think we should be giving a very strict advice on what to do with patients.
I think each patient should be treated individually, their own set of issues that lead to a benefit risk assessment. And so, I would never want to tell a doctor for giving advice based on a single risk factor. If their MS is severe enough and they haven’t responded to other treatments, they should still consider TYSABRI. And so it’s an individual benefit risk decision.