Assuming that they are currently roughly at the same stade of evolution as us, or less, and knowing that Voyager 1, the farthest human made object in space, only crossed the heliopause eleven years ago, it's not highly probable that "something" would have reached us by now. Of course, it's based on an assumption, but the contrary is too. The thing is we don't know enough to estimate when, where and how life might have appeared elsewhere.