Now, just two years later, the dreaded disease is back. And the quick-to-smile 4-year-old from Washington D.C, is fighting to beat it again.
Celebrities are rocking Twitter to help him win. According to his family's site, MatchDevan, the list of big names that have helped to generate 21 million tweets is incredibly long:
Kim Kardashian, Lance Armstrong, Buzz Aldrin, Ashton Kutcher, Paris Hilton, Jessica Alba, Demi Moore, and Nicole Richie, are just the tip of the iceberg.
But Devan and his family have hit a major road block.
Devan's mother's family is from India. His father's heritage is European. That means Devan's stem cells are very rare. His chances of finding a matched donor for a bone marrow transplant are very slim. Without new stem cells he will die.
"We really thought we dodged that bullet. We were done. He was cured," his mother, Indira Lakshmanan, told CBS News medical correspondent Dr. Jonathan LaPook. "We found out we were wrong."
But Indira wasn't giving in.
As a Bloomberg reporter, she knew a thing or two about getting her message out.
News outlets picked up Devan's story. Celebrities like Paris Hilton, Kim Kardashian and Arnold Schwarzenegger hit their massive Twitter fan bases on Devan's behalf.
But despite a huge effort to sign up new donors to the database of 14 million bone marrow donors, no match was found for Devan's unusual genetic make-up.
That is, until his family turned to a new batch of donors that has been mostly ignored - parents who donate cord blood that comes from an umbilical cord after birth.
There are currently less than 200,000 cord blood donations in the nation's public banks, but still a fairly good match was found for Devan. That's because it's easier to match stem cells harvested from cord blood than from bone marrow.
It can be used to treat conditions like lymphoma and leukemia. Yet, according to LaPook, umbilical blood is discarded as medical waste in the vast majority of the more than four million births occurring each year.
"It is the single most miraculous waste of a miraculous treatment in medicine that I know of," he says.
That's why Devan's family is now fighting to help others.
"Just because you heard that Devan has a partial backup match just in case a perfect match isn't found, don't let that stop you from going to the registry," says his mother Indira. "Don't let that stop you from saving a life."
For more information on donating cord blood visit: Cord Blood Donation.
For more information on becoming a potential bone marrow donor, visit here: Swab-a-Cheek.
To see Devan's efforts to find donors for other patients visit his site: MatchDevan.