An Ohio man who overdosed on an opioid spray prescribed to treat back and knee pain may proceed with some claims against maker Insys Therapeutics Inc.

But the U.S. District Court for the Northern District of Ohio limited the scope of the suit.

Subsys, a form of fentanyl that’s administered as a spray under the tongue, was approved to treat cancer pain. Ohio residents Michael and Julie Kelley alleged Insys encouraged the use of Subsys for the “off-label” purpose of treating general pain despite knowledge it was highly addictive.

In July 2016, Julie found her husband unresponsive with respiratory failure...