Humanoids who shared their world with the Menk and were dying from a genetic illness that Phlox and Archer chose not to cure.
The Valakians are a humanoid species who share their homeworld with the Menk, a less advanced humanoid people. By the 22nd century the Valakians had developed space flight, but their population was being devastated by a genetic disease spreading among them.
In Dear Doctor, a Valakian ship appealed to Enterprise for help, and Phlox worked to find a cure. He came to believe the illness was part of a natural evolutionary process that would let the Menk flourish, and Archer decided not to share the cure, giving the Valakians only a treatment for their symptoms.