Ben Gilmer chokes up when talking about walking his daughter down the aisle last May. He wasn’t sure he’d be alive to make that stroll after hearing in 2014 he had stage IV non-small cell lung cancer.

 “My wife, Donna, and I were stunned, because I’ve never smoked and I’ve always been active,” says Ben, who turned 72 in November. “I owe my life to the experimental drug I’m taking.”

“Ben and I were adamant about wanting...