According to the company, the antibody lecanemab slows down mental decay in Alzheimer’s patients. That sounds hopeful. The only question is: hopeful for the patients or the manufacturers?
The world is waiting for effective Alzheimer’s drugs. In Switzerland alone, around 150,000 people live with dementia.
On Tuesday, the American pharmaceutical company Biogen communicated the most important study results for their Alzheimer’s drug lecanemab. If the company’s plan goes according to plan, the US Food and Drug Administration (FDA) should approve accelerated approval for the antibody in December. Ordinary market approval should then take place in March. The drug is also to be launched in the EU.
No sooner had Biogen and its Japanese partner Eisai released the news about lecanemab than the media started talking about a breakthrough in the treatment of Alzheimer’s. And good chances of a billion dollar market. However, it is definitely too early for such predictions. And for several reasons.
First, Biogen has not yet presented the study data collected in a so-called phase 3 study in any scientific journal. This is annoying. Because the results lack the seal of approval of an independent review by experts. Such an approach is likely to be commercially motivated. From a medical-scientific point of view, it is harmful. Because it prevents a serious assessment of the drug. At this point, one can only believe or not believe the presented results. Knowledge works differently.
Secondly, the communicated results are anything but brilliant. In the study with almost 1,800 subjects with early-stage Alzheimer’s, the drug is said to have reduced the progression of mental deterioration over 18 months by 27 percent compared to the untreated control group. Is that a lot or a little? Opinions differ on this. It’s like the glass half full and half empty. For some, such an effect is better than nothing in a disastrous disease like Alzheimer’s. For others, the effect on the individual patient is hardly detectable in everyday life.
Even the Biogen CEO does not seem to be completely convinced of his drug. In any case, he allows himself to be quoted in very cautious words in the company announcement: The announcement gives patients and their families hope that lecanemab, if approved, possibly slow the progression of Alzheimer’s disease and have a clinically meaningful impact on cognition and function.
In addition, the possible benefit cannot be had without side effects. Lecanemab can cause swelling and, rarely, bleeding in the brain. According to the company, the investigators found evidence of brain swelling in 21 percent of the patients treated in the magnetic resonance imaging (MRI); in the placebo group it was 9 percent.
The study results with lecanemab are almost identical to another Alzheimer’s drug from Biogen: the failed antibody aducanumab (brand name Aduhelm). Both substances lead to a measurable reduction in so-called amyloid, a protein in the brain classified as a driver of Alzheimer’s. Aducanumab even received FDA approval in June 2021 – albeit against the advice of an independent panel of experts. Many therefore spoke of a political decision.
With approval, aducanumab was the first new Alzheimer’s drug since 2003. It was also the first substance that can modulate the course of the disease in patients. The braking effect on cognitive decay was given as 22 percent. As already mentioned, it is 27 percent for the new Biogen drug.
The fact that aducanumab failed miserably despite FDA approval is due to the fact that the company was unable to dispel the smoldering doubts about the benefits of the drug. That’s why health insurers in the US refused to cover the cost of the drug. And the European regulatory authorities refused the drug from the outset the market approval.
This is not to say that the new Biogen drug lecanemab will suffer the same fate. But the signs are that this drug will not become the holy grail of Alzheimer’s therapy either. It could possibly become a first building block in a combination therapy. Because when the brain breaks down, not only the amyloid clumps play a role, but many other factors. Instead of always relying on new antibodies against amyloid, it would be time to pursue a broader approach in the development of effective Alzheimer’s drugs.
However, effectiveness is not the only thing that counts for society. Equally important is the question: do the benefits justify the costs? Because the money that is spent on medicines may then not be used for the care and support of demented patients. When the aducanumab failed, the bill was obvious to most. The annual treatment costs were initially around 56,000 dollars. This did not include the costs for the regular MRI examinations to detect swelling.