Drug company Novartis is betting $20 million on a cancer treatment that seems to have saved a little girl's life, according to a report from The New York Times' Denise Grady.

Just last spring, six-year-old leukemia victim Emma Whitehead was "near death," having gone through chemotherapy twice without success.

But then her parents put Emma through an experimental treatment at Children’s Hospital of Philadelphia.

They infected her with a version of HIV, reprogrammed to attack cancer cells.

Whitehead almost died, but the treatment worked and now she's in remission — and doing cartwheels all over her house.

Grady says the treatment hasn't worked for all patients.

It worked completely on three adults. Four treated adults have merely improved. A child relapsed. The treatment failed two adults completely.

Here's the thing though: Each of these patients was a "hopeless" case before trying the treatment. So any success is huge.

Emma in April:

Emma now:

Here's a video from the Children's Hospital of Philadelphia:

Grady's story has lots of quotes from optimistic doctors, as well as a detailed description of how the reprogrammed virus does its work >