New kid on the block ready to fight

Many of you may have heard  the recent news about a medication that has recently been approved for the treatment of early Alzheimer’s disease.

This understandably has created hope for those affected by the condition.

The medication (donanemab) has already been approved for use in a number of countries overseas, including where I am writing this article: the US.

In May this year, it was approved  for use by doctors in Australia  (through the Therapeutic Goods Administration). Unfortunately, it has  not yet been approved for subsidisation by the Pharmaceutical Benefits  Scheme, meaning that it can only be prescribed privately.

At this point, with a 12-month script you may not see much change from $50,000. And that is just the cost of the medication itself, not the associated expense of monitoring investigations and doctors’ visits.

For some, however, this might be a price worth paying. Donanemab is the first medication ever available in this country that modifies the underlying disease process of Alzheimer’s.

So how does it work? Well, you may recall from previous columns that Alzheimer’s disease is underpinned in part by the build-up of a protein, amyloid, in the brain.

This accumulates in plaques between the nerve cells and is associated with the damage and death of those cells.

Donanemab binds to amyloid. It induces an inflammatory response in the brain, whereby the amyloid is engulfed and removed. This can be dramatically demonstrated using special brain scans called amyloid PET scans.

The great hope has been that  removal of amyloid will lead to a cure  or a reversal of symptoms, including improved memory. This is not the case with donanemab.

What it does do is slow down cognitive decline for some. In the major study to date, this is in the order of  30 per cent. Compared with a group not receiving the drug, over an 18-month period, those on donanemab showed a decline equivalent to 13 months. In other words, they were five months better off.

What is unknown, and what might be more convincing for sceptics, is if this 30 per cent slowing persists over the longer term. If it did, that might mean that  the drug could buy you an extra three years of better quality of life over a 10-year period.

This month, perhaps even before you are reading this article, the PBS will decide whether to pay for cost of the medication – meaning that it will be financially accessible for most people.

If it does, this will radically change  the treatment landscape of Alzheimer’s in Australia.

And taking donanemab is not  without risk. It is given as a monthly infusion and there is the possibility of a reaction to that infusion. Then, there are the specific side effects of the medication on the brain. These fall into two main categories: brain swelling and brain bleeding. The risk of both is relatively low, but not insignificant.

Most of the time, these problems are only detectable on an MRI brain scan, and anyone on donanemab needs to have these regularly while on the treatment.

Sometimes, however, they can result in serious side effects, including death – more so for the brain bleeding.

So, the decision about using the medication is complicated and ultimately a personal one. I’m sure I will be having plenty of conversations with those under my care about it in the coming months, and many more so if it is PBS subsidised.

What is certain is that, exciting as  the progress being made is, when it comes to a cure, it is important not to forget all the other lifestyle choices that influence the brain.

 Kailas Roberts is a psychogeriatrician and author of Mind Your Brain: The Essential Australian Guide to Dementia, available at bookstores and online. Visit yourbraininmind.com or uqp.com.au