The patient was enrolled at Shepherd Center, a spinal cord and brain injury rehabilitation center in Atlanta.
In order to participate, the patient had to have been injured within the last two weeks. The company, Geron, hopes to enroll another eight to 10 patients in the study.
The stem-cell drug, known as GRNOPC, contains cells that turn into oligodendrocytes, a type of cell that produces myelin, a coating that allows impulses to move along nerves.
When those cells are lost because of injury, paralysis can follow. If GRNOPC1 works, the progenitor cells will produce new oligodendrocytes in the injured area of the patient's spine, potentially allowing for new movement.
Because this is an early stage study, researchers are primarily concerned with the safety of the treatment.
"When we started working with human embryonic stem cells in 1999, many predicted that it would be a number of decades before a cell therapy would be approved for human clinical trials," Dr. Thomas B. Okarma, president and chief executive officer of Geron said in a statement.
Embryonic stem cells have been at the center of funding controversies because the research involves destroying human embryos, which some have argued is akin to abortion.
But, many researchers consider embryonic stem cells the most versatile types of stem cells, as they can morph into any type of cell.
While a milestone in the technology, the drug is still a long way from being proven and reaching the market. It still faces many years of testing for effectiveness if all goes well in the early stage study.