The United States Food and Drug Administration (FDA) has approved donanemab-azbt, Eli Lilly's investigational monoclonal antibody designed to target and clear amyloid plaques from the brain, which are believed to contribute to the progression of Alzheimer's disease, and marketed as Kisunla for treating the disease.

The drug regulator, in a communiqué, recommended administering Kisunla as an intravenous (IV) infusion every four weeks to individuals in the early stages of the disease, particularly those with mild cognitive impairment or mild dementia.

More than 6.5 million Americans and around 50 million people worldwide suffer from Alzheimer's disease, a degenerative brain ailment, with estimates predicting a rise to 150 million by 2050. It gradually deteriorates memory and thinking skills, making it harder for people to do routine activities. The specific origins of Alzheimer's disease are unknown, although they entail changes in the brain, such as the accumulation of amyloid beta plaques and tau tangles. These alterations cause the loss of brain cells and their connections, affecting memory, thinking, and speech capacities.

A trial of 1,736 Alzheimer's patients assessed the drug's effectiveness, leading to the FDA's approval. These patients had mild cognitive impairment or dementia with proven amyloid pathology. The researchers divided the participants into two groups, one receiving Kisunla and the other a placebo. Kisunla was administered every four weeks for a total of 72 weeks, beginning with 700 mg for the first three doses and increasing to 1400 mg for the subsequent doses.

The trial results revealed that patients treated with Kisunla demonstrated a significant reduction in cognitive deterioration when compared to those given a placebo. This was assessed using a variety of scales, including the Integrated Alzheimer's Disease Rating Scale (iADRS), the Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog13), and the Alzheimer's Disease Cooperative Study-IInstrumental Activities of Daily Living (ADCS-iADL). The study comprised patients ranging in age from 59 to 86, with an average of 73. The majority were white, with some Asian, Hispanic or Latino, and Black or African American participation.

The drug regulator put a warning about amyloid-related imaging abnormalities (ARIA) in the instructions for prescribing Kisunla. These usually show up as short-term brain swelling that goes away on its own over time. ARIA may also contain small areas of bleeding in or on the brain and is usually symptom-free, though serious events might occur in rare situations.

The FDA noted that patients with two copies of the ApoE ε4 gene are more likely to develop ARIA, including severe instances, compared to individuals with one or no copies of the gene. To determine the risk, it is advisable to test for ApoE ε4 status prior to starting medication, the communiqué added.

The drug regulator pointed out that infusion-related responses may include flu-like symptoms, nausea, vomiting, changes in blood pressure, and severe allergic reactions such as anaphylaxis and angioedema. Kisunla's most common side effects include ARIA and headaches.