By Stephanie Stahl

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PHILADELPHIA (CBS) —  The FDA just approved a new cancer drug that’s already showing promise. It works entirely different than chemotherapy and doctors believe it could be transformative in the field of precision medicine.

It was tested on one little girl and the results were dramatic. Looking at Rihanna Plaza today, you would never know that she was born with a tumor the size of her newborn head.

“I just cried, I knew something was bad. Why did it have to be rare, and why did it have to be my daughter?” says Ana Plaza, Rihanna’s mother.

Rihanna started intensive chemotherapy right away, but after several months, the massive, cancerous tumor wasn’t shrinking.

The family connected with doctors at Memorial Sloan Kettering Cancer Center who were testing a new drug called Vitrakvi. It targets a specific gene mutation in the tumor.

rihanna plaza Its A Miracle: New Cancer Drug Shows Promise In Curing Patients

Credit: CBS3

Rather than going after tumors based on where they originate, Dr. Neal Shukla says this treatment targets cancers with a certain gene mutation.

“We are really trying to move away from treating patients based on just where the cancer arises and really treating them based on what makes the cancer tick,” explains Dr. Shukla.

Rihanna received the drug twice a day at home and her parents saw immediate results.

“I called the doctor and said, ‘This thing is shrinking, oh my God,'” says Plaza.

Rihanna also had no side effects and within months, the tumor became small enough for doctors to perform surgery without compromising the function of her arm.

Today, all that’s left is a scar and she’s cancer-free.

“We were like where does this happen, it’s a miracle,” says Plaza.

The drug has been effective in treating 11 other cancers, including lung and colon.

Stephanie Stahl