Looking at the Wikipedia page there are a number of trans neptunian objects with much greater aphelions:

https://en.wikipedia.org/wiki/2018_VG18

It is just the farthest out right now.

https://en.wikipedia.org/wiki/Extreme_trans-Neptunian_object

There are likely many, many more we haven't found yet.

https://en.wikipedia.org/wiki/Sednoid

For comparison it is often announced in the media that voyagers 1 and 2 have "left the solar system". Voyager 1 is about 144AU out right now. There are things in orbit of the sun with aphelions from 1500 to 3000AU.