Kisunla treatment stops once amyloid plaques are reduced to a certain level. In the Kisunla clinical trial, half the patients stopped taking the drug after a year after their brains had cleared amyloid plaques. It isn’t clear why some people cleared plaques faster than others. After 18 months of bi-weekly Leqembi infusions, treatment moves to monthly infusions or weekly under-the-skin injections. Many specialists will likely order an amyloid PET scan 12 to 18 months after a patient starts taking Leqembi or Kisunla and then use the information from the scan to guide further treatment.