Long‐term safety and immunogenicity of ABvac40 active immunotherapy in mild cognitive impairment and very mild Alzheimer's disease: Results from AB1601 phase 2 extension study
María Pascual‐Lucas, Ana María Lacosta, María Montañés, Jesús Canudas, Jorge Loscos, Inmaculada Monleón, José Antonio Allué, Leticia Sarasa, Noelia Fandos, Judith Romero, Manuel Sarasa, Mireia Torres, Dermot Whyms, Jose Terencio, Gerard Piñol‐Ripoll, Mercè BoadaAbstract
INTRODUCTION
ABvac40 is an active immunotherapy targeting A β 40, the main component of cerebrovascular deposition in Alzheimer's disease (AD). A 24‐month randomized, placebo‐controlled phase 2 study (Part A) showed favorable safety and robust immunogenicity, with exploratory signals of clinical efficacy. Here, we report results from Part B, an 18‐month extension evaluating long‐term safety and immunological memory.
METHODS
Participants treated with ABvac40 in Part A received placebo plus a delayed booster, whereas previous placebo participants received ABvac40. Exploratory endpoints included safety, tolerability, and immunogenicity.
RESULTS
Seventy‐seven participants entered Part B. Treatment‐emergent adverse events (TEAEs) occurred in 75.0% of participants in placebo + booster group and 81.1% in ABvac40 group; serious TEAEs were 5.0% and 16.2%, respectively. No ARIA‐E or meningoencephalomyelitis were observed, with one ARIA‐H event. ABvac40 induced robust antibody responses following delayed booster, with detectable anti‐A β 40 antibodies in CSF.
DISCUSSION
ABvac40 showed favorable long‐term safety and durable immunogenicity, supporting further clinical development.
TRIAL REGISTRATION
ClinicalTrials.gov: NCT03461276, registered March 2, 2018. EudraCT: 2016‐004352‐30, registered March 10, 2017.