Anything can be intercepted, the faster they fly, the less they can maneuver. It's relatively simply to fly an intercept course and light off a fragmenting warhead, the target provides the kinetic energy for the kill.
It will stress reaction time, but that thing isn't gonna get there on it's own, a big fat platform is going to have to release it from about 20 miles away. The obvious answer is to kill the platform before it gets anywhere near you.
The Japanese perfected this technology during WWII.