No. There is no such theory, yet. The unification of gravity and quantum physics is the Holy Grail of physics. It's one of the largest single points of effort in modern physics. There are a couple of approaches being pursued, and it is hoped that one of them someday will bear fruit, but we aren't there, yet.
In any case, don't expect practical applications (such as antigravity) from it, once they find it. The energy scale for such a unification is gigantic (unless there are large extra dimensions we can't see, in which case it is merely huge), a fact called the "hierarchy problem". The interaction scale would be some 27 orders of magnitude greater than the typical scale of chemical interactions, a condition that could only have existed in nature in the first ten millionth of a trillionth of a trillionth of a trillionth of a second of the Big Bang.