A 49-story apartment tower proposed — with some zoning deviations — to fill one of the last blanks in Biscayne Boulevard’s high-rise canyon wall in downtown Miami is headed for city review.

New York-based PMG plans to build a 646-unit building, including 47,902 square feet of offices and 3,006 square feet of commercial-retail space, at 400 Biscayne Blvd. The tower would rise nearly 562 feet and include a garage with 527 parking spaces.