By: Robert W. Griffith, MD
Enbrel® (etanercept) is a powerful anti-inflammatory drug that's given by subcutaneous injection. It's reserved for moderate to severe cases of rheumatoid arthritis, ankylosing spondylitis, and psoriasis, and it works as an anti-tumor necrosis factor-alpha (TNF-alpha) agent.
This mechanism of action led Dr Edward Tobinick of the University of Southern California to conduct trials of Enbrel in patients with mild to moderate Alzheimer's disease. The first study was of 15 patients treated weekly with perispinal injections of the drug. (The injection is given into the fluid-filled cavity surrounding the spinal cord in the neck region; it's followed by adoption of a head-down posture for 5 minutes to allow the drug to flow down into the cerebrospinal venous system.) In this open-label study (i.e. one where the doctors are fully aware of the treatment given) there was significant improvement in MMSE scores, as well as in other tests of cognitive ability.
Now Dr Tobinick has published remarkable results in one patient within minutes of the perispinal injection of Enbrel. His report in the Journal of Neuroinflammation contains details of the pre- and post-injection tests - orientation (year, place), picture identification, animal naming, and so on.
We must remember that this was an open, uncontrolled study with very small patient numbers. As Dr Paul Rosenberg of Johns Hopkins puts it: "The Alzheimer's field has plenty of open-label studies and case reports of improvement that have not panned out into new useful treatments. [Without confirmation in a controlled trial], you shouldn't get too excited". Furthermore, Dr Tobinick owns stock in the manufacturer of etanercept, and has multiple patents (pending and issued) describing this use of etanercept.
An independent editorialist , Dr Sue Griffin of the University of Arkansas , points out that the route of administration of the drug is novel, and may be a valid route for other drugs like Enbrel. I hope that research will be supported in this direction, as well as with Enbrel itself, as these results are the best we have seen for some time.
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