Pot’s Illicit History Makes Patenting Hard in the Legal-Weed Era

When Canopy Growth Corp. announced a plan to acquire cannabis researcher Ebbu Inc. for $330 million last October, it touted the company’s intellectual property as the primary reason for the deal, mentioning it five times in the short press release.

A year later, Canopy is struggling to turn that intellectual property into patents. One of Ebbu’s first applications was rejected twice by the U.S. Patent and Trademark Office. When it was then narrowed significantly in a renewed attempt at approval, it was rejected a third time.

The difficulties Ebbu has faced in securing patents point to a broader issue ...