The problem with lean beef is that it is very dry. Some binder and a little filler, plus liquid helps combat this problem.
My burgers:
93/7 lean ground beef, 2lbs
1/8 cup panko crumbs
2 whole eggs
1 1/2 oz worcestershire sauce
1-2 oz burgundy wine (nothing top shelf, but nothing you wouldn't drink)
Salt, white pepper, garlic powder, and onion powder to preference.

Mix all ingredients in a bowl, form into patties. Be cautious not to over work the meat, it will become tough. Be sure to cook ground beef to a minimum internal temperature of 150 degrees Fahrenheit. These are nice individually wrapped in plastic wrap for easy freezer storage.

High protein, low fat, and the added touch of resveratrol
I've been using this recipe for years and get nothing but compliments on them. I hope you enjoy.

This burger is great topped with caramelized onions and provolone cheese.