Recently, the company Biogen, in consultation with the European Medicines Agency (EMA), withdrew the approval of the MS drug Daclizumab. The reason was that, in addition to a death due to an autoimmune liver inflammation, which had already led to a restriction of the substance’s indication, there have now been cases of brain inflammation that were causally attributed to the drug. In light of these events, the benefit-risk assessment for the preparation was negative, also against the background of sufficient therapy alternatives for the treatment of relapsing-remitting MS.
I have indeed taken note that in the comments on my blog this process is seen as proof that I recommend MS drugs far too “carelessly” and fundamentally underestimate the risk of MS therapy.
I have read my article about Daclizumab from autumn 2017 again and one can certainly retrospectively criticize that I evaluated the substance too enthusiastically and thus did not live up to my responsibility, which I have with this blog. On the other hand, the presentation at that time was justified given the safety data available. Nevertheless, one should probably point out more clearly that a reliable safety assessment for new substances can only be made after about 100,000 patient years and that every new substance (this also applies to Ocrelizumab at the moment) can always hold surprises in real-world use that clinical studies, despite all care, do not capture because they often work with selected and limited numbers of participants.
From a scientific point of view, it is a pity that Daclizumab has failed, because the concept behind the substance was immunologically very interesting and it enriched the therapeutic spectrum. Of course, these considerations are secondary to patient safety – but they were part of the reason for my positive assessment of the substance at that time.
What is by no means justified, however, is a comparison with the Thalidomide scandal, which was drawn in comments. On the contrary, I think that the events surrounding Daclizumab show that our system of pharmacovigilance works well, and has evolved and improved significantly since the 60s. Side effects and unexpected events are carefully recorded (worldwide), independently evaluated, and if necessary, timely consequences are drawn for the sake of patient safety – in this case, even the complete withdrawal of an MS drug (which was not good news for many patients who were successfully treated with this substance and got along well with it).
Of course, any complication that can be directly attributed to a drug is one too many and particularly terrible for the person who is harmed as a result. Nevertheless, even with the greatest care in drug development, 100% safety can never be guaranteed. A residual risk always exists, especially due to the large individual differences between patients in terms of their genetic makeup, pre-existing conditions and other individual circumstances. This natural residual risk is justified given the now very good effectiveness of MS drugs – in my opinion, too little is discussed about the fact that poorly treated MS also poses a considerable “health risk”.
Our patients can rely on the fact that doctors, scientists, health authorities and the pharmaceutical industry carefully monitor new drugs and keep an eye on possible complications. Nobody is interested in cover-ups today – the case of Daclizumab illustrates this very impressively. The system of pharmacovigilance works. This must also be taken into account in the assessment of an event such as the withdrawal of Daclizumab.
