Very few, if any, companies would donate money towards a "cause" without getting something in return.
Indeed, most if not all companies that participate in such things, do it in order to get more exposure (and in turn most customers, and in turn more money).
At the end of the day, everything is about money. The companies really couldn't give a damn about actually finding a cure. What they care about is their bottom line. If participating in finding a cure or donating toward charities wasn't profitable, they wouldn't do it.