A Star Trek-themed derivative doesn’t infringe Dr. Seuss’ "Oh, the Places You’ll Go!” largely because it’s transformative and serves a different market, a federal court ruled.

Former Star Trek screenwriter David Gerrold defeated copyright and trademark claims by Dr. Seuss Enterprises, which owns rights to the late author’s work, in a March 12 summary judgment by the U.S. District Court for the District of Southern California.

Gerrold’s book, “Oh, the Places You’ll Boldly Go!,” purposefully imitated the poetry structure and...