Scientists have completed initial tests on a new drug for advanced melanoma and report that it yields positive results in treating this type of malignancy. Melanoma is the most serious form of skin cancer.
A research team from UCLA's Jonsson Comprehensive Cancer Center completed the initial clinical trial of the Merck drug lambrolizumab (MK3475), according to ScienceDaily. They noted positive effects in 135 patients with advanced melanoma.
The National Cancer Institute estimates that more than 45,000 U.S. men and 31,000 women will die in 2013 after developing melanoma of the skin. Healthcare providers classify melanoma as advanced when the skin cancer has spread from the point of origin to another region of the body. Unfortunately, while treatments can extend the lifespan of a patient with advanced melanoma, the disease can't be cured once it has reached that stage, says Cancer Research UK.
The UCLA team reported their findings in the New England Journal of Medicine. They divided patients into three groups and assigned each group a different treatment plan.
Considering all the patients, 38 percent on MK3475 experienced confirmed improvement. Among those on the lowest dose, a quarter had improvement. Of those on the highest, 52 percent improved.
The scientists didn't calculate the average duration of patient response because they removed from the study five subjects with initial responses after their melanoma worsened. So far, the longest response has exceeded a year.
Researchers were encouraged that any side effects were typically mild and easy to manage: fever, fatigue, muscle weakness, loss of skin color, and skin rash. More severe side effects like kidney or lung inflammation affected 13 percent of the subjects.
According to researcher Dr. Antoni Ribas, UCLA professor of medicine, the trial showed that lambrolizumab had the greatest rate of durable responses among any of the drugs tested for melanoma. Experts believe the drug works by reactivating the immune system in an advanced melanoma patient.
Human T cells track and obliterate invading substances responsible for disease and infection. However, the human immune system doesn't typically sense melanoma, which can spread without detection by T cells. Scientists postulate that a protein known as PD-L1 found on the surface of the malignant cells cloaks them from T cells.
MK3475 is actually an antibody that jump-starts the immune system to catch melanoma cells. The researchers believe that after treatment, the immune system somehow remembers melanoma as an invader and keeps on managing it for an extended period.
The outcome of the first trial resulted in more tests of the drug on patients with other types of malignancy, such as lung cancer. The U.S. Food and Drug Administration has designated lambrolizumab a breakthrough therapy. This designation facilitates expediting the development and review of potential new drugs designed to treat serious or life-threatening conditions.
Vonda J. Sines has published thousands of print and online health and medical articles. She specializes in diseases and other conditions that affect the quality of life.
- Disease & Medical Conditions
- National Cancer Institute
- skin cancer