I've seen many a good cast-iron pan ruined by a wire wheel.
Were it mine:
Wash it in hot, soapy water. Rinse well.
Fill the sink with enough hot water to cover the pan. Pour in a pint or so of distilled white vinegar. Let it soak for an hour or so. You should begin to see bubbles in a few minutes.
Use a stainless steel scrubbie - not an SOS pad - to clean it once the vinegar has loosened the rust. Rinse it. Now you can decide if it needs further cleaning, e.g, removing baked-on grease or other gunk.
NOTE: I've done this many, many times. I usually go after the grease and grime first, then the rust.
Just my $0.02.