By Dr. Cynthia Paulis
There seems be a breakthrough in treatment for melanoma patients with two drugs approved by the FDA last year, Yervoy (ipilimumab) and Zelboraf (vemurafenib).
Melanoma, a skin cancer, causes death in almost 9,000 Americans annually and has had an alarming rise of occurrence in young women between the ages of 18 and 35. Though it accounts for just 4 percent of all skin cancer, it is the most lethal form of such cancer. With early detection and proper treatment the cure rate for melanoma is 95 percent, but finding it early is the key. Once the cancer spreads, patients with inoperable melanoma will live just a few months.
The two new drugs work through completely different mechanisms. Yervoy, developed by Bristol-Myers Squibb, works by allowing the body’s immune system to recognize, target and attack cells in melanoma tumors. It is a monoclonal antibody that blocks a molecule known as cytotoxic T lymphocyte antigen that may involve a role in slowing down or turning off the body’s immune system, thereby affecting its ability to fight off cancerous cells. The drug is administered intravenously in four infusions over a three-month period. The cost of the drug is high, $120,000.
In clinical tests, patients lived an average of 10 months versus 6 months without the drugs, but some have lived for two to three years after the treatment.
Along with the cost, there is another drawback. Yervoy can take up to two weeks to work versus other chemotherapy drugs with can kill cancer cells quickly, and if a person has a very aggressive form of melanoma there may not be enough time for it to work.
Yervoy does not work directly on the tumors but works on the immune system; as a result some of the side effects can be colitis, diarrhea, hepatitis, endocrine dysfunction and skin problems. According to the FDA, 12.9 percent of patients treated with Yervoy suffered severe or fatal autoimmune reactions.
Zelboraf, unlike Yervoy, is a prescription medication of two capsules taken twice a day. The drug works by targeting a specific mutation in the BRAF gene that is responsible for approximately half of all stage four melanomas. It will not work on the melanomas without the BRAF gene. In clinical trials 132 patients taking Zelboraf were followed for 13 months. More than half of the patients in the study had their tumors shrink by 30% and another 33% of the patients showed that the drug slowed or stopped progression of the tumors. Fourteen percent of the clinical trial patients had no improvement. More than half the patients were alive after 16 months and some for a few years. The drug costs $9,400 a month and is also covered by insurance.
The side effects of the drug include joint pain, rash, skin that burns easily in the sun, fatigue and hair loss. Approximately 25 percent of the patients who take the drug may also develop new squamous cell skin cancers. These cancers are less dangerous than melanoma and can be removed by a dermatologist.
With both Yervoy and Zelboraf, these are not medications that will cure end-stage melanoma but they have proven to extend the person’s life.
Dr. Anna Pavlick, associate professor of oncology at NYU Langone Medical Center, spent nine years involved in clinical trials with the new drugs and is one of the authors of a report on melanoma in the New England Journal Medicine in February. In a phone interview, she said, “Zelboraf will make a big difference in the lives of BRAF-positive melanoma patients. We now have the capacity to analyze the patient’s melanoma tumor for the genetic mutation BRAF and use Zelboraf to attack the tumor, shrink it, and stop the progression of this deadly disease.”
Dr. Pavlick remains hopeful for a future cure for this deadly disease. “This is just a small step in the management of malignant melanoma,” she said. “We still need to do research to continue to find a cure so people can lead long and productive lives.”
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