VirnetX is a listed company. Apple could simply buy them out from under the Board's feet and throw them in the dumpster and not even notice the cost.
About a day and a half. (that's based on 2017's $48 billion net income)
So Apple almost certainly could afford to buy the company, but they'd need a business case for doing so, weighing that option against all the OTHER nice things they might want to spend $200 million on.