Lecanemab (Leqembi) for mild Alzheimer's dementia

Lecanemab was found to have no advantages.

Reaction to the infusion: Early analyses suggest that lecanemab has a disadvantage here. With lecanemab, about 23 out of 100 people had symptoms that could be related to the infusion, such as a fever and chills. Without lecanemab, around 7 out of 100 people had these kinds of symptoms.

Life expectancy: Based on the study data, the researchers deduced that there was no difference in life expectancy between the groups during the 18-month study period.

Severe side effects and stopping treatment due to side effects: About 10 to 14 out of 100 people in each group had severe side effects. In total, around 3 to 7 out of 100 people in the study stopped their treatment because of side effects.

There was also no difference between the groups regarding the following aspects. IQWiG concluded this based on the responder analyses provided by the manufacturer. This kind of analysis makes it possible to see how many people's symptoms were noticeably worse after 18 months.

• Dementia symptoms: The dementia symptoms were noticeably worse in around 27 to 34 out of 100 people, regardless of whether they had received both lecanemab and cholinesterase inhibitors or just cholinesterase inhibitors. The symptoms were assessed using the CDR-SB score.
• Memory and thinking skills: In each of the groups, the participants' memory and thinking skills became noticeably worse in around 14 to 23 out of 100 people.
• General health: There was a noticeable decline in overall health in around 16 to 22 out of 100 people, regardless of which treatment they had received.
• Health-related quality of life: In each of the groups, this became noticeably worse in about 10 to 17 out of 100 people.

Swelling and bleeding in the brain: The manufacturer did not provide suitable data on these side effects for the relevant subgroup of patients with mild Alzheimer's dementia. But based on the overall evaluation of the study results, it cannot be ruled out that lecanemab causes swelling and bleeding in the brain.

The manufacturer did not provide any suitable data on the participants' independence in daily life or changes in behavior.

It is also not clear whether lecanemab has different effects in men and women or in people of different ages when used to treat mild Alzheimer's dementia. The manufacturer did not provide suitable data for the relevant subgroup here.

The study did not look at the effects of lecanemab when used alone (monotherapy). Because of this, it is not clear whether lecanemab (on its own, without cholinesterase inhibitors) has any advantages or disadvantages compared to cholinesterase inhibitors (the currently recommended standard treatment) in adults with mild Alzheimer's dementia.

This information summarizes the main results of a review produced by the Institute for Quality and Efficiency in Health Care (IQWiG, Germany). The review was commissioned by the German Federal Joint Committee (G-BA) as part of the “early benefit assessment of medications.” On the basis of this review and the hearings received, the G-BA will pass a resolution on the added benefit of lecanemab (Leqembi).