Revolutionary progress has been made in the treatment of skin cancer, as NBC's "Today" show recently reported on a new drug being used to treat stage 3 and 4 melanoma -- the most serious form of skin cancer. The drug, owned by Bristol-Myers Squibb, is known as Ipilimumab, or "Ipi."

In clinical trials of people suffering from stage 4 melanoma, "in 20 percent to 30 percent of patients getting the drug, the response was spectacular -- the advanced cancer that had spread through their bodies either dramatically reduced in size, or simply disappeared. The other 70 percent to 80 percent of patients had no response at all," according to results presented at the annual meeting of the American Society of Clinical Oncology (ASCO) in Chicago and published in The New England Journal of Medicine.

Unfortunately, doctors cannot yet predict who will respond best to the treatment, but of the 9,000 people who die from melanoma each year, this treatment can reduce that number by almost 30 percent.

So how does "Ipi" work?

"Ipilimumab is a laboratory-made protein called an antibody. It attaches to and stimulates certain white blood cells (called CD8 killer cells) which in turn destroy the melanoma when the drug works. 'Ipi' does not cause the usual nausea and hair loss associated with chemotherapy."

"Melanoma has given cancer a bad name and has been the graveyard of many new drugs. So, this is producing tremendous excitement both for the clinical researchers who are in the battleground of this horrible disease, as well as the patients and their families," as Dr. Steven O'Day, lead researcher of the study and head of the Angeles Clinic and Reserch Institute in Santa Monica, California, told NBC News.

Want to learn what you can do to prevent melanoma? Slather on one of these broad-spectrum sunscreen every single day, and reapply early and often.