Professor Robert Moots explains about biologic treatments for rheumatoid arthritis.
Over recent years however we've learnt much more about what causes rheumatoid arthritis, and as we've learnt these things we've been able to design new drugs that specifically inhibit important parts of the pathways that cause the inflammation. The first drugs that were developed in this way were the TNF alpha blockers. TNF stands for tumour necrosis factor, and this is an important chemical that causes inflammation and is particularly high in rheumatoid arthritis. What we learnt is that if we inhibit this chemical, patients get better. And there are three drugs that are available at the moment that do this. First of all infliximab, then etanercept and adalimumab. So they're very complicated names, but the bottom line is that they neutralise this inflammation chemical and this can help get people better.
So let's consider these individually. First of all infliximab. This is a protein like the others, but an antibody. And the antibody is made up of a tiny fragment of part of a mouse antibody coupled to a human antibody. And this drug is given by intravenous infusion. So patients have to go in and have a drip gradually going though into the vein over a period of a few hours. And once patients are stable on this treatment, the drug is given every eight weeks. The other drug, adalimumab, is also an antibody, but it's a fully human antibody and therefore people are a bit less prone to develop an intolerance to it, which I'll explain in a minute. The third drug, etanercept, also a protein, is coupled, is a human antibody coupled to the natural receptor for TNF alpha. So adalimumab and etanercept are actually given by the patient as an injection under the skin, a subcutaneous injection. Etanercept is given once a week, and adalimumab is given once a fortnight.
These drugs are also known by their trade names. Infliximab is also known as Remicade. Adalimumab as Humira, which is much easier to pronounce. And etanercept is also known as Enbrel. We know that all three of these TNF blockers work very well. In fact these have become the gold standard for treating rheumatoid arthritis because they give the best results. However, it's important to know that not everybody with rheumatoid arthritis needs a TNF alpha blocker. Patients with milder disease can do perfectly well on simple drugs. And at the moment in the United Kingdom we have to reserve the TNF blockers for people who have got bad disease and who have also not responded to the simple drugs, including methotrexate. But if you're in that situation, you're not responding to the simple drugs and you do have bad disease, then you will be eligible to have this treatment. TNF blockers are given by rheumatologists, and it's important that their delivery is supervised by a rheumatologist from a hospital.
As I've mentioned, these drugs give the best chance of responding if your disease is bad. But also, like any drug, there is always a risk of a side effect. The side effects that we know about which are likely in some patients on a TNF blocker re