yes, but make certain they are sealed tightly against freezer burn, and you shouldn't re-freeze the cooked lasagna. When you cook them and they haven't been defrosted, you need to add some cooking time (think about all of the frozen entres in the freezer section at the supermarket).
Also, depending on the ingredients, the texture may suffer. If you have a lot of vegetables, some of them may suffer. Tomato sauce will be OK but tomato chunks will become sauce.
If you are using frozen vegetables instead of fresh it isn't advisable to refreeze the vegetables, so it wouldn't be advisable to freeze the lasagna if containing pre frozen veggies.
