There has been efficacy for people with dyslexia. Fonts like comic sans are closer to their own writing and therefore are easier to read.

You can also look at the Geronimo Stilton book series, a lot of words appear in different colors / fonts to emphasise words. These books are often easier for children and those with dyslexia to read.

Note: I still feel like calling it a typeface that makes reading easier is inappropriate. No study has specifically been conducted on this typeface, and drawing conclusions from (limited, and arguably unrelated) studies and and anecdotes is dubious at best.