A two-year-old boy has been given a second chance at life after being diagnosed with a devastating disease.

Despite a healthy appearance, when Gideon Purchase was six-months-old, the infant began losing his appetite, started sleeping poorly, and became more fussy than usual. Unaware of the crushing truth, Katie and Gary Purchase thought their son's changes were the result of teething, TODAY reports.

Things took a turn for the worse when a yellowish bruise appeared, covering both of Gideon's eyes, along with a lump emerging from his head. After visiting emergency, Gideon was transferred to St. Jude Children's Research Hospital, where they discovered he had been battling stage 4 neuroblastoma, a rare type of cancer.

"His entire face and skull was full of cancer, and all of his bones were full of cancer," Sara Federico, a doctor at St. Jude's said. "He had a large tumor that was present in the middle of his body."

Despite the diagnosis, all was not bleak for the family, because the doctors had come up with a plan.

The physicians quickly went to work to start Gideon on the hospital's newest clinical trial that offered a unique approach to immunotherapy.

The trial offered the uses a new technique, which combined an antibody during all the stages of the chemotherapy treatment.

It quickly became a success and there was a striking change in Gideon in only six weeks. Federico said the early results were surpassing all of the doctors' wildest expectations.

"He went from 84% of his marrow having tumor to 0%," she added.

While most of the tumors dramatically shrunk, Gideon still had to endure a bone marrow transplant and radiation, which would take 15 months worth of procedures.

Today, Gideon has been deemed cancer free.

"It makes you appreciate the little things. Suddenly, life's problems just don't seem like a big deal anymore," Gary said. "He makes us treasure every day."