No cheese = no pizza.
We make a homemade pizza without adding any salt to the crust, sauce, or sausage, and it comes out fine. Seasonings include garlic, fennel, oregano, and crushed chilis. Toppings (besides the homemade sausage) include sliced tomato, diced green pepper, diced onion, and sliced mushrooms.
Pepperoni is good too, but not essential, as it does have quite a bit of salt. (We slice it up & nuke it just a bit to drive off some of the excess grease.)
But we DO use cheese - mozzarella and just a bit of Romano. The cheese and meat probably account for 99% of the sodium.