Not really, but that depends on your definition of “scale”. To make one that scales well, you’ll need to solve a few difficult computer science problems that conventional database architectures don’t need to consider and therefore don’t address. These are problems like graph cutting, multi-attribute search without secondary indexes, cache-less I/O schedulers, and a couple others. Scalable solutions to all of these problems exist independently but I’ve never seen any graph database implementations that even attempt to address most of these, never mind all of them, and you kind of need to remove these bottlenecks.

As long as most graph databases are just a layer of graph syntactic sugar sprinkled on top of a conventional database architecture, they won’t scale.