Pharmaceutical Technology

EU CHMP snubs Biogen and Eisai’s Alzheimer’s therapy Leqembi

The European agency said that Leqembi’s efficacy was “not large enough” to outweigh its safety risks.

The European Medicines Agency (EMA) has halted Eisai and Biogen’s expansion plan to launch its Alzheimer’s disease therapy Leqembi (lecanemab) in Europe after its drug review committee recommended against the therapy’s approval.

The Committee for Medicinal Products for Human Use (CHMP) stated that Leqembi’s positive effect on delaying cognitive decline was “not large enough” to counterbalance the associated risk of serious adverse events. Eisai was quick to add that the company plans to re-examine the CHMP opinion.

The committee was particularly concerned with the risk of developing amyloid-related imaging abnormalities (ARIA). These are observed exclusively on MRI and can signify oedema, effusion and /or haemorrhage.

CHMP noted that “although most cases of ARIA in the main study were not serious and did not involve symptoms, some patients had serious events, including large bleeds in the brain which required hospitalisation.” The risk of ARIA was increased in patients with ApoE4 gene, the presence of one or more copies of the gene predisposes an individual to develop Alzheimer's disease.

The committee also pointed out that the difference in the improvement of cognitive decline, measured using the Clinical Dementia Rating Scale Sum of Boxes (CDR-SB) score, between the Leqembi and placebo arms was “small”. Adding that “the seriousness of this side effect should be considered in the context of the small effect seen with [Leqembi].”

Leqembi works by targeting the buildup of amyloid plaques in the brain, a hallmark of Alzheimer’s disease and a suggested cause of memory and cognition impairment. It received accelerated approval from the US Food and Drug Administration (FDA) in January, which was converted into full approval earlier this month.

Leqembi is an important drug for Biogen, which is codeveloping the drug with Eisai, especially after the former discontinued its other controversial Alzheimer’s treatment Aduhelm (aducanumab-avwa), in January. A GlobalData analysis forecasts Leqembi to generate over $6.1bn in sales by 2030.

GlobalData is the parent company of Pharmaceutical Technology.

Eisai and Biogen have also filled a supplemental biologics application (sBLA) with the US FDA for monthly Leqembi IV maintenance dosing for the treatment of patients with Alzheimer’s disease, with the Prescription Drug User Fee Act (PDUFA) action date being set for 25 January 2025.