AstraZeneca's Anselamimab Shows 62% Survival Improvement in Kappa Light Chain Amyloidosis Despite Missing Primary Endpoint
核心洞察
AstraZeneca's CARES Phase III program failed to meet its primary endpoint in the overall AL amyloidosis (搜索) population, but demonstrated significant benefits in a prespecified kappa light chain subgroup.
Anselamimab showed a 62% improvement in survival and 71% reduction in cardiovascular hospitalizations in patients with kappa light chain amyloidosis (搜索) compared to placebo.
The potential first-in-class anti-fibril therapy represents the first treatment to show clinically meaningful survival benefits by targeting existing amyloid fibril deposits in this rare disease affecting approximately 74,000 patients worldwide.
AstraZeneca's investigational anti-fibril therapy anselamimab demonstrated significant clinical benefits in patients with kappa light chain amyloidosis (搜索), despite the CARES Phase III clinical program failing to meet its primary endpoint in the overall AL amyloidosis (搜索) population. The results, published in the Journal of Clinical Oncology and presented at the 2026 American Society of Clinical Oncology Annual Meeting, represent a potential breakthrough for a subset of patients with this rare and progressive disease.
Significant Survival Benefits in Kappa Subgroup
In a prespecified subgroup analysis of patients with kappa predominant light chain isotype, anselamimab improved survival by 62%, measured by all-cause mortality (hazard ratio 0.38; 95% confidence interval [CI] 0.17, 0.86; nominal p=0.012), and reduced the frequency of cardiovascular hospitalizations by 71% (incidence risk ratio 0.29; 95% CI 0.10, 0.87; nominal p=0.028), compared to placebo.
The reduction in mortality risk was observed across both Mayo staging categories within the kappa subgroup, with a 75% reduction in patients with Mayo stage IIIa disease and a 48% reduction in those with Mayo stage IIIb disease. Notably, no differences in all-cause mortality and cardiovascular hospitalizations were observed among patients with lambda predominant light chain isotype.
First-in-Class Mechanism Targets Amyloid Deposits
Anselamimab represents a potential first-in-class anti-fibril therapy designed to improve organ function by reducing or depleting amyloid deposits in tissues and organs. The monoclonal antibody binds with specificity to targets within amino acids on misfolded amyloid fibrils (搜索), promoting destruction and clearance of amyloid deposits while sparing native free light chains from destruction.
"The CARES Phase III program is the first to show that targeting existing deposits of amyloid fibrils (搜索) could deliver clinically meaningful survival and cardiovascular benefit in adults with kappa light chain amyloidosis (搜索)," said Gianluca Pirozzi, Senior Vice President, Head of Development, Regulatory and Safety, Alexion, AstraZeneca Rare Disease.
Addressing Critical Unmet Need
AL amyloidosis (搜索) is a rare, systemic and progressive disorder caused by defective plasma cells in the bone marrow. Abnormal light chain proteins (搜索) produced by these plasma cells misfold, aggregate and form amyloid fibrils (搜索) that deposit in tissues and organs. Left untreated, the accumulation of these toxic amyloid deposits, particularly in the heart and kidneys, can cause progressive organ damage and dysfunction and may lead to premature death, most commonly due to cardiac failure (搜索).
Worldwide, there are an estimated 74,000 patients living with AL amyloidosis (搜索), approximately 20% of whom have kappa light chain amyloidosis (搜索) and approximately 80% of whom have lambda light chain amyloidosis (搜索).
"People living with advanced AL amyloidosis (搜索) often face persistent, progressive and debilitating organ damage with no available options to target and clear existing amyloid fibril deposits," said Ashutosh Wechalekar, Honorary Consultant Haematologist at University College London Hospitals and lead principal investigator of the program.
Comprehensive Clinical Program Design
The CARES clinical program represents the largest prospective investigation in cardiac AL amyloidosis (搜索) to date, with 406 patients enrolled from 19 countries globally. The program consists of two parallel global, Phase III, randomized, double-blind, placebo-controlled, multicenter trials evaluating anselamimab plus standard of care for underlying plasma cell dyscrasia in patients with light chain amyloidosis and cardiac involvement.
Patients were randomized 2:1 to receive either anselamimab or placebo once weekly for the first four weeks and then every two weeks until study completion. Approximately 80% of patients received daratumumab as part of their treatment regimen alongside cyclophosphamide, bortezomib and dexamethasone.
Quality of Life and Functional Improvements
At 50 weeks, numerical improvements favoring anselamimab were observed in key secondary endpoints among kappa light chain amyloidosis (搜索) patients. Quality of life, as measured by the Kansas City Cardiomyopathy Questionnaire-Overall Score, showed a Hodges-Lehmann median difference of 10.37 (95% CI -9.38, 25.56; p=0.113). Functional capacity, measured by the Six-Minute Walk Test, demonstrated an improvement of 18.00 (95% CI -71.60, 95.92; p=0.145) compared to placebo.
Safety Profile and Regulatory Status
Treatment with anselamimab was generally well tolerated in the overall population, including the kappa subgroup. The therapy had an acceptable safety profile, with the majority of adverse events balanced between the anselamimab and placebo groups and consistent with the underlying medical condition and its treatment with standard of care plasma cell dyscrasia treatments.
Anselamimab has been granted Fast Track Designation by the US Food and Drug Administration and received Orphan Drug Designation from the US FDA, European Commission and the Ministry of Health, Labour and Welfare of Japan for the treatment of AL amyloidosis (搜索).
The company indicated it looks forward to continued engagement with health authorities to advance this potential first-in-class anti-fibril therapy for patients with kappa light chain amyloidosis (搜索), who can be easily identified by simple, routinely-used diagnostics.