The Phase 2b Pronto study did not meet its primary or secondary endpoints. A phase 3 Vital Amyloidosis study is also being discontinued based on futility analysis.
AL amyloidosis is a rare, progressive and typically fatal disease induced by extracellular deposition of misfolded immunoglobulin light chains.
Prothena president and CEO Gene Kinney said: "We are surprised by the results from these two placebo-controlled studies and will continue to analyze the resulting data to share insights with our collaborators in the scientific, medical and advocacy communities.
‘We thank all of the patients, their families, caregivers, investigators, study staff and our employees. Their participation in and commitment to these studies are indispensable to advancing our shared goal of improving the lives of patients with amyloidosis."
Vital amyloidosis study was a phase 3 global, multi-center, randomized, double-blind and placebo-controlled clinical trial of NEOD001 against placebo in treatment-naïve patients with AL amyloidosis and cardiac dysfunction.
The company recruited 260 newly diagnosed and treatment-naïve patients with AL amyloidosis and cardiac dysfunction in the trial, and randomized them on a 1:1 basis to secure 24 mg/kg of NEOD001 or placebo via intravenous infusion every 28 days.
According to the firm, the futility analysis, based on 103 adjudicated events of the 156 events specified to complete the study, was not statistically significant.
Pronto study was a phase 2b global, multi-center, randomized, double-blind, placebo-controlled clinical trial of NEOD001 against placebo in previously-treated patients with AL amyloidosis and persistent cardiac dysfunction.
Prothena recruited 129 previously-treated patients with AL amyloidosis with persistent cardiac dysfunction in the study. Here also, the firm randomized patients on a 1:1 basis to receive 24 mg/kg of NEOD001 or placebo through intravenous infusion every 28 days.