An injected version of Leqembi worked as well as the FDA-approved intravenous version at removing the toxic amyloid protein implicated in Alzheimer’s, according to data presented at the Clinical Trials on Alzheimer’s Disease annual meeting.
The data came from an extension of the phase 3 Clarity AD trial, which won Leqembi its FDA approval. Compared with the original version, a subcutaneous injection of the drug cleared 14% more amyloid plaque in the brain among 71 patients who hadn’t received Leqembi before.The biomarker analysis, done after six months of treatment, was preliminary. There was no data comparing the two formulations on their ability to slow cognitive decline.
Despite the positive efficacy data, a closely watched safety measurement raised some eyebrows. But analysts argued the readout shouldn’t be a concern.
Specifically, subcutaneous Leqembi showed a numerically higher rate of amyloid-related imaging abnormalities (ARIA), a known side effect of anti-amyloid antibodies like Leqembi. The rates of brain swelling, known as ARIA-E, were 16.7% and 12.6% for subcutaneous (SC) and intravenous (IV) Leqembi, respectively. The rates of small brain bleedings, known as ARIA-H, were 22.2% and 17.3%, respectively.
ARIA is a potentially life-threatening condition. The side effect has been a major concern when evaluating the benefit-risk profile and commercial potential of Leqembi and other anti-amyloid drugs.
