Cook asparagus in pot of simmering water until tender, 7 to 9 minutes. Drain.
Divide asparagus into 6 equal bundles. Wrap each bundle with slice of prosciutto; place in shallow flame-proof dish.
Melt butter in small saucepan over medium-low heat. Add bread crumbs; cook, stirring, 1 minute. Pour mixture over each bundle. Top with Gruyère cheese.
Heat broiler. Run bundles under broiler until cheese lightly browns, about 1 minute.