Actually until some future date US Medicare will not pay for it as there is no method to apply for coverage in place (special rules apply). It is not a cure and you still progress but for up to 30% it may be a few months to a year slower path. As it is known as the "long goodbye" now not sure that will be much of an improvement for anyone but the drug maker, those selling and those taking care for renumeration. But, as with cancer, we tend to welcome any extensions of stay here on earth as positive.
https://nypost.com/2023/07/07/da-approves-robust-dementia-drug-that-slows-cognitive-decline/