AFFIRM-AL Study Protocol Amendment

AFFIRM-AL Study Protocol Amendment

June 23, 2022

Prothena has recently implemented an amendment for the AFFIRM-AL Phase 3 study of birtamimab in Mayo Stage IV AL (light chain) amyloidosis which is currently recruiting patients. Birtamimab is an investigational monoclonal antibody designed to target and clear the abnormal protein (amyloid) that can accumulate and cause organ failure in patients with AL amyloidosis. 

The amendment has expanded the number of sites globally from 80 to 120 in over 20 countries and will also allow the use of daratumumab as part of standard of care treatment if initiated at randomization to align with emerging changes to standard of care.


  • The AFFIRM-AL Study is a global, randomized, phase 3, efficacy and safety study that will compare birtamimab plus standard of care to placebo plus standard of care by assessing time to all-cause mortality.
  • The goal of this clinical research study is to evaluate an investigational drug called birtamimab to find out if it works and if it is safe when given with chemotherapy to people with AL amyloidosis who are in Mayo Stage IV.  The study will enroll approximately 150 patients.
  • Patients who may be eligible are 18 years of age or older, newly diagnosed with Mayo Stage IV AL amyloidosis, and have not yet received any medical treatment for AL amyloidosis.
  • Patients will receive birtamimab or placebo by intravenous infusion monthly and will also receive concurrent standard of care therapy consisting of a first line regimen that contains a drug called bortezomib.

For more information about the AFFIRM-AL study, please visit the AFFIRM-AL website ( or (