In this case, two of the quasars are quite close together, suggesting that they may be interacting. The more distant one, while also gravitationally bound, is less likely to have been involved in the formation of the system.
The only other known triple quasar was discovered as recently as 2007, going by the name of QQQ J1432−0106. At a rather more distant 10.5 billion light years away, it's been studied well enough to know that these quasars are around 100,000–150,000 light years away from each other. To us, that might sound like they're rather far apart, but it's fairly typical for interacting galaxies.
ANALYSIS: Quasars Help Shed Light on Dark Energy Mystery
One curious finding with the newest triplet, however, is the lack of ultra-luminous infrared galaxies (ULIRGs) nearby. This is contrary to what might be expected, as quasars and ULIRGs are commonly found in the same neighborhoods. The team that discovered these quasars suggest that this may mean that they're part of a larger structure which is still forming as we see it.