Nowadays, multiple sclerosis is primarily treated with oral medications such as dimethyl fumarate or teriflunomide in many cases. The interferon preparations, which were the standard in basic therapy for many years, have a bad reputation among many patients due to flu-like side effects and skin reactions at the injection site. However, interferon preparations also have many advantages. They are especially effective in the early phase of the disease and are also a very safe treatment option. With more than 20 years of experience with interferons, we can be sure that we will not experience any more surprises in terms of safety. We know that no organ damage is to be expected even with long-term use and that a desire to have children can also be realized without major problems under interferon preparations.
Even though the safety data from studies on Aubagio® and Tecfidera® were very good, we cannot yet offer our patients the same safety as with interferons when taking the new tablet preparations – they have not been in practical use long enough. However, safety plays a major role for many patients with chronic diseases – especially in moderate disease courses, because a balanced benefit-risk ratio is of particular importance here. Therefore, interferons and Copaxone remain important despite oral competition. And that’s why I would like to draw attention to a new development in interferons that many patients, as well as practicing doctors, have not yet sufficiently noticed:
In the summer of 2014, Plegridy®, the first pegylated interferon preparation, was approved. Pegylation means that the interferon molecule (the actual active ingredient) is “packaged” in polyethylene glycol (PEG). This chemical modification leads to a delayed release and thus an extension of the duration of action of interferon-beta. Therefore, when using PEG-interferon, the injection only needs to be administered every two weeks – the substance is injected into the skin (subcutaneously) like Rebif®) or Betaferon®). The pegylation of drugs is a well-established principle in medicine and has already made significant progress in the interferon therapy of hepatitis (inflammatory jaundice). PEG itself (the “packaging material”) is harmless and is used in many everyday products, such as toothpaste, creams and lipsticks. The studies on pegylated interferon (Plegridy®) in MS achieved good results, even though the preparation was only injected every two weeks. The relapse rate, disability progression and MRI activity could be significantly reduced compared to placebo – the results were comparable to the study results of the “old”, non-pegylated interferon preparations. This also applies to the safety profile of Plegridy®, which – as expected – corresponds to the side effect profile of the non-pegylated interferon preparations.
Flu-like side effects and reactions at the injection site are in the foreground, no new safety aspects were found. A small downside, however, is the observation that not only does the effect of interferon last longer, but also the side effects. Some patients report longer-lasting flu-like side effects with higher consumption of non-steroidal anti-inflammatory drugs (e.g. Ibuprofen) and a larger extent of injection reactions, which are also visible for longer. Therefore, there may be patients who prefer to forego use due to these side effects – even if the preparation only needs to be given every two weeks. However, for those who find these side effects acceptable and are looking for a safe therapy characterized by simple application, Plegridy represents an interesting treatment option. The same applies to pegylated interferon, that the side effects in many patients occur mainly in the initial phase and improve on average after three months. Since the concept of an “escalating” immunotherapy is still pursued in MS therapy, where initially – except in very aggressive courses – therapy is carried out with moderately effective, but safe preparations, I consider the availability of a pegylated interferon to be an interesting development in MS therapy.
