Addressing one of the first substantive rulings in the Risperdal litigation in California, an appeals court has potentially reinstated hundreds of lawsuits after partially reversing a key decision on federal preemption.

The lawsuits allege that anti-psychotic drug Risperdal, made by Johnson & Johnson’s Janssen Pharmaceuticals, causes boys to develop breasts—a condition called gynecomastia. In 2017, Los Angeles Superior Court Judge William Highberger granted summary judgment in lawsuits coordinated in California state courts based on federal preemption.