Dr. Keith Flaherty had proudly described the extraordinary recovery of the melanoma patients in the experimental drug trial, led by him as extraordinary, but unfortunately several of the patients on the trial of the drug known as PLX4032 have relapsed and even one has died from cancer that crossed the blood-brain barrier which the new drug cannot penetrate.

Many of the trails participants were still in remission. Those who had relapsed were searching for another treatment.

The results were a promising sign for an approach to treatment for all forms of cancer. PLX4032 held off the cancer by blocking a particular protein in the cells that spurred them to multiply.

The targeted therapies for other cancers, faced a problem that while PLX4032 blocked the protein made by one mutated gene, a second mutation seemed to be drive the cancer’s growth.

Dr. Flaherty’s colleagues in the laboratory would search for the new mutation in the tumor samples of patients who had relapsed and try to understand why the drug stopped working.