There are three questions in the Rare Diseases Day video which ask about allergy and immunity to eculizumab. These may be speculative rather than based on experience and are really concerns about the drug not working effectively for some individuals.
To date the alliance is only aware of two situations where eculizumab has been found not to work:
- There are some individuals with a “polymorphism” mutation ( something which are more common in the general population and not rare like mutations which are significant for aHUS ) on the C5 complement component; and which prevents eculizumab specifically from doing its job. The best known polymorphism has been reported in Japan and was featured in an alliance news blog about aHUS in Japan ( click here) In such cases an alternative complement inhibitor like Coversin may be needed.
- The other situation is when patients do not actually have aHUS
The only other concern of clinicians is where a resistance is developed by the body, like some other drugs.
The alliance is not aware of this happening to aHUS patients; and as far as is known there have been no such incidents reported by the PNH research community, for which eculizumab has been in use for a much longer time.
If such adverse events did take place then clinicians have duties, and ways, to report the matter to Alexion, ,and particularly to the aHUS Registry Clinical Trial which begun in 2012 and will be open until 2025.
There is a contact point for INC Research who operate the trial aspect of the Registry which can be found the Clinical Trials website on this link: https://clinicaltrials.gov/ct2/show/NCT01522183
aHUS is a complex illness and small differences in those affected by it result in different outcomes and why in time its treatment will become more and more personalised.
It seems it takes many hits for aHUS to happen in the first place for some yet others may not onset despite facing the same circumstances. Why that may be is yet another question as answered in a previous blog .