Seeking additional treatment for non-Hodgkin’s lymphoma presented a challenge for Emily Dumler in 2013.

At the time, she and her husband, Scott, had three young children, and they all lived in Kansas City. But the chemotherapy and stem cell transplant she’d already received locally hadn’t worked, and the CAR T-cell therapy clinical trial Emily wanted to try was only available at MD Anderson in Houston, about 650 miles away by air...