OKLAHOMA CITY - The FDA has approved a new drug doctors are calling a cure to a deadly disease and some Oklahomans played a part in making it happen.

The drug is called Kalydeco and it treats cystic fibrosis.  Doctors say it can cure a rare form of the disease that affects just 1,200 people in the U.S., which is about 4 percent of cystic fibrosis patients nationwide.

Currently, the average life span for C.F. patients is only 37 years. But doctors are calling this drug the biggest development for the disease since it was first diagnosed.

For the past nine years, Capri Faulk and her family have been living with the realities of cystic fibrosis.

"My child was going to die young, that she may not get married, that she may not even graduate from high school," Capri's mother Nicole Faulk said.

But back in July of 2009, they learned of a clinical study. Capri's parents quit their jobs, sold their house, and moved to Tennessee.

"We were willing to give up everything we knew," said Nicole. "Give up all of our family that we had here, all of our support, just for a chance for our daughter to be healthy."

Within three weeks they noticed it was working.

"I just sat on the curb and bawled and bawled and bawled."

"It will save lives starting immediately," Dr. James Royal, who heads the Cystic Fibrosis Center of Oklahoma, said.

Royal worked on some of the trials.

"I'm happy to use the word cure."

Statement from the Cystic Fibrosis Foundation:

"It is too early to say whether Kalydeco is an actual cure for cystic fibrosis. It's important to know that the drug works only in people with a specific genetic mutation (called G551D), which represents 4 percent of the U.S. population with the disease. What is exciting about Kalydeco from the perspective of the Cystic Fibrosis Foundation is that it is the first drug that goes beyond treating the symptoms of the disease and instead addresses the root cause of CF. The research behind this drug is opening new doors to research for a possible cure for all people living with cystic fibrosis."

Since she started on the drug, Capri has gained 30 pounds and her lung function is the best it's ever been. With FDA approval, other families now have the same hope.

"When I found out it was approved I don't think I've ever been so happy in my entire life except when I gave birth to my three kids," Nicole said.

The drug will only work on about four percent of C.F. patients with a specific mutation, but Dr. Royal said it's proof the process works, giving hope to everyone else. He said in 10 years or so there will be similar drugs for the most common mutations as well.

Kalydeco will be in pharmacies the week of February 6.