Memantine

Does anyone know what the effects of memantine are — they tell me it will (or MIGHT) stabilize my love at his current level of ability (which is better than him getting worse naturally) but I am wondering how it affects the overall course of the disease. (as if we know what that is!) What I am wondering (and I suppose it is wicked) is whether this drug means he will be “stabilised” like this for another decade? Or if the typical disease profile still applies?