It's the leading cause of death from skin disease. Last year alone, nearly 9,000 people died from melanoma.
Traditional treatments are ineffective, giving most patients with advanced melanoma less than a year to live.
Now, a new FDA approved drug is the first ever to improve survival, and it's adding months, even years, to patients' lives.
Karen Anderson takes time to reflect on her life. Doctors gave her just six months to live after a biopsy from a lump on her neck revealed this.
"My surgeon said, 'You know, you have Stage 4 melanoma,' and it was just kind of like wow," says Anderson.
The melanoma had spread to her lymph nodes, breasts, liver and bones.
She's already lost her father, sister and step-dad to other forms of cancer, but Karen is determined to beat it. She enrolled in a clinical trial with the help of lead investigator, Doctor Walter Urba.
Ipilimumab, or Ippy, works by stimulating the patient's own immune system to kill tumors. It's the first FDA-approved drug for melanoma in more than a decade.
"It allows T-cells to grow, multiply, produce molecules that go on and kill melanoma cells wherever they live throughout the body," says Dr. Urba.
With Ippy, the median survival rate is improved by four months.
"It gave me three years, almost three years, that I would not have had if I hadn't been on it," explains Anderson.
While Ippy has given Karen more precious time with her daughter, the melanoma has come back.
"Ippy" is marketed under the name Yervoy. It represents a new class of drug known as targeted T-cell therapy.
It's also being looked at to help treat prostate, breast, lymphoma and lung cancers.