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SC lecanemab more effective at amyloid plaque removal than IV form
The latest data from Japanese drugmaker Eisai and its partner Biogen, presented at the Clinical Trials on Alzheimer's Disease conference in Boston, indicates that after six months of treatment, the SC form of lecanemab removed 14% more beta amyloid than the IV formulation, which received full approval from the FDA in July.
Administered as a set of two consecutive injections every week, SC lecanemab could simplify use of this novel Alzheimer's treatment, potentially allowing patients to receive the drug at home instead of traveling to an infusion center every two weeks as is currently required with the IV form.
Eisai and Biogen said in a news release that they plan to apply for U.S. approval of SC lecanemab by the end of March 2024.
Key study takeaways
- In this open-label extension of the Clarity AD study, 72 patients who received lecanemab for the first time as the SC formulation were compared to 322 patients who received IV lecanemab in the Clarity AD core study followed by SC administration in this substudy.
- Weekly SC administration led to 14% greater amyloid plaque removal than biweekly IV administration according to preliminary analysis using amyloid PET at 6 months of treatment.
- Reduction from baseline of amyloid in the brain by amyloid PET at 6 months in the newly treated SC patients by centiloid reduction was -40.3 ± 2.27 with SC administration compared to -35.4 ± 1.14 with IV administration.
- Blood concentration levels of lecanemab were 11% higher with SC administration than with IV.
- Rates of infusion- or injection-related side effects were lower for the SC vs. IV formulation: About 15% of patients had injection site reactions, described as “mild and moderate in severity,” with redness, irritation or swelling.
- Incidence of amyloid related imaging abnormalities with edema (ARIA-E) was similar between SC and IV administration. Incidences of ARIA-E, ARIA-H (cerebral microhemorrhage due to ARIA, cerebral hemorrhage, and brain surface hemosiderin deposition) and ARIA-H alone (ARIA-H without ARIA-E) with IV lecanemab in the Clarity AD core study were 12.6%, 17.3% and 8.9%, respectively. In newly treated patients in the SC substudy, incidences of ARIA-E, ARIA-H and ARIA-H alone were 16.7%, 22.2% and 8.3%, respectively. However, due to the sample size of newly treated patients in the SC substudy, an exact comparison could not be made.
Sources:
Steenhuysen, J and Beasley, D. (2023, October 26). Reuters. Injected version of Eisai/Biogen Alzheimer's drug works as well as IV Leqembi. https://www.reuters.com/business/healthcare-pharmaceuticals/injected-version-eisaibiogen-alzheimers-drug-effective-side-effects-higher-2023-10-25/
Constantino, AK. (2023, October 25). CNBC. More convenient form of breakthrough Alzheimer's drug Leqembi shows promising results in study. https://www.cnbc.com/2023/10/25/alzheimers-drug-leqembi-shows-promise-as-injection.html
(2023, October 25). Eisai/Biogen. Eisai presents new Leqembi® (lecanemab-irmb) investigational subcutaneous formulation interim study results and clinical improvement data in earlier stages of early Alzheimer's disease from additional analyses of Clarity AD at the Clinical Trials on Alzheimer's Disease Conference. https://www.multivu.com/players/English/9211051-eisai-at-ctad2023/