A nonprofit organization dedicated to scientific research on cannabis plans to build a $24 million medical-marijuana-research facility at a proposed Licking County grow site if voters approve ResponsibleOhio’s marijuana-legalization amendment this fall.

Work at International Cannabinoid Institute Research Foundation will focus on marijuana-centered therapies for certain medical conditions, such as childhood epilepsy, post-traumatic stress disorder, Alzheimer’s disease and cancer.

The nonprofit group would lease 15 acres from the property owner of the Licking County site, located in Pataskala, for the 40,000-square foot facility, the group announced on Tuesday at a news conference outside the Statehouse.

ICI began working on its flagship research facility in 2013. After the ResponsibleOhio amendment was proposed, the group decided to work the facility into the confines of the ballot initiative, said ICI founder Garrett Greenlee.

ICI seeks to prioritize medical-marijuana patients, Greenlee said. Because the amendment would legalize personal as well as medical-marijuana use, the...