MCI-- treatment with Lecanemab or Donanemab

I was diagnosed with MCI in April 2024. I am also APOE 3/4. After much research, I elected to start on Leqembi. I just had my 15th infusion, with zippo reactions. I am aware of the concerns with ARIA (Amyloid Related Imaging Anomaly), which include swelling and bleeding in the brain. In the clinical trials, most occurrences of ARIA had no side effects (they were only noticed in the early mandatory MRIs whare are taken after the 4th, 6th, and 13th infusion). The few with severe ARIA had some nasty outcomes. However, for many of them, the issues went away after stopping treatment. Seems like life in general - there is always some risk, such as driving on a highway to visit relatives. There are lots of car accidents in the U.S. and tens of thousands of people die each year, but most of us don't worry about such things when we set off on a trip. I found the risk vs reward decision pretty easy.

Today there are the two products you mentioned. I happen to like to use the common names of Leqembi and Kisunla. The both had similar results in their Phase 3 trials in terms of percentage reduction in the Clinical Dementia Rating - Sum of Boxes score after 18 months of treatment (29% reduction with Kisunla, 27% reduction for Leqembi). If you are unfamiliar with the CDR-SB methodology, it is apparently standard in the AD world, determining how well people perform on a test involving memory, orientation, judgment, community affairs, home hobbies, and personal care. A score of zero in a category means no impairment, a score of 3 indicates severe impairment. As an example, for home & hobbies, a score of 0 indicates life at home and hobbies are well maintained. A score of 0.5 in this category indicates these abilities are slightly impaired, there is a mild but definite impairment for a score of 1, very restricted interests for a score of 2, and a score of 3 means no significant function in the home. In other words, this seems to be a very practical test to see how well a person can operate in the world.

Keep in mind the above numbers are averages over the entire population of those participating in the trials. The detailed numbers are available split by age (older folks had larger reductions than younger folks), gender (males had larger reductions than females), and APOE4 status (noncarriers had largest reduction, followed by heterozygotes, and then homozygotes). However, I think all of these are not so useful, as they include people with varying degrees of cognitive decline at the start of the trial. People in your shoes would really want to know how people of your gender/age/APOE4 status AND a specific starting cognition might perform with the drug. Alas, that sort of information isn't available.

Kisunla is dosed via a monthly IV, Leqembi is currently a bi-weekly infusion. Leqembi has been around longer (approved by the FDA in Jan 2023) versus a July 2024 approval for Kisunla. Eisai (Japanese company that manufactures Leqembi) likes to advertise that Leqembi works by "by continuously clearing protofibrils and rapidly clearing plaque" (quoting from a recent Eisai press release). Thus, people on Leqembi stay on Leqembi until their cognitive decline gets to a point where folks decide treatment should end. With Kisunla, treatment stops after amyloid is cleared from the brain.

Yesterday, Eisai issued a press release stating that the FDA accepted their application for a subcutaneous version of Leqembi for maintenance dosing (i.e. people could use this after 18 months or so of initial treatment). The idea is this shot could be performed at home, avoiding IVs. Again, this is for maintenance dosing only, folks still have to have about 18 months of initial IV treatment. The press release indicates the FDA set an action date for the Eisai application on Aug 31, 2025 (i.e. the date when the FDA might approve the Eisai application).

I am not sure how the end user costs compare for the two drugs. My co-pay for my bi-weekly infusions of Leqembi is around on $400. I'm on a private medical plan (not old enough for Medicare).

In other comparisons I've seen between the two drugs, nobody mentions the dosage. For Leqembi, the dosage is dependent on your body weight: 10 mg of Leqembi per kg of body weight. For example, my dosage is 600 mg of Leqembi (I weight over 60 kg which is 132 pounds, but they apparently round down to the nearest 100 kg). Kisunla is a fixed dosage of 700mg for the first 3 and later doses are 1400 mg. So if you are heaver or lighter than average weight, you might be getting less than average or more than average dosage of Kisunla, respectively.

I think the following website has a good comparison of Leqembi & Kisunla.

My husband was diagnosed with MCI and AD tendencies at 67. His Tau protein in the spinal fluid was literally one dot, on the graph, below for being positive for AD. He started Leqembi in May 2024, just had #19 infusion. He takes a premed of 650mg tylenol and 50 mg benedryl 30 minutes before we arrive, due to a mild infusion reaction including chills, a low grade temp, and being achey, after his first infusion. He also gets IV Push steroids 30 mins before the Leqembi starts. The day following he feels fine but is flushed. Tylenol or Motrin help with that. It does not keep him golfing or going to the YMCA. All his brain MRIs were unchanged so we have continued with the treatments. His disease process does seem to have progressed! That is what the med, Leqembi, is supposed to do so YEAH! He thinks he knows people and their names easier. He usually sleeps in the comfy recliner that is both heated and has a massage option during his infusion. I take my laptop or something to work on. During the winter I walk in the hall to my mile in and when the weather gets nice again I will walk outside. He still does not like change of any type, and still has trouble with following through to complete a project. Change is his biggest trigger. To make it easy on both of us I try to keep him in his comfort zone. Same breakfast every morning which he makes, he worked a factory so he likes the same type of lunch, which he prepares. Generally I try not schedule appointments in the morning because he like to go to the Y to workout. He has been asked to try pickle ball by some of the people there but that is change…. When golf season starts he will golf in the morning expect for that senior league one evening a week. I do not go the Y or the golf course with him. Driving to places he knows is fine but following directions is not good. If we are going somewhere different I do most of the driving. He is on Medicare and has a Med Mutual Supplemental insurance. The treatments are covered by both the insurances and we do not have a co-pay.

Best Wishes to you and your wife. I hope all goes well.

I take two Tylenol and one Claritin just before infusion at 9 am, then 6 hours later two Tylenol and again 6 hours more one Tylenol. If you buy it yourself the cost is about $2.10 at the infusion center (you must tell the infusion center that is OK'd by a neurologist). If it was provided by the infusion center, it's $12.44 just for the two Tylenol & one Claritin and you'd need to buy more Tylenol for the two at home that same day.

It's hard to know what happens once you start doing it, but the two Tylenol later at home day seem to be very simple to do.

We are burning tree limbs today!