It is likely that, in the near future, a sample of an individual’s cancer will be carefully and extensively analyzed in the laboratory before any therapy is started. The results of this analysis will allow us to select a treatment that will likely work the first time. By matching drugs to the specific defects in an individual human being’s cancer, we should be able to avoid the “trial and error” approaches of today.
In 2011, two new cancer treatments were approved that illustrate this new paradigm. Crizotinib (Xalkori®) was approved for the treatment of lung cancer that harbors a specific mutation in the ALK gene. Vemurafenib (Zelboraf®) was approved for the treatment of melanoma, the deadliest form of skin cancer. This drug targets BRAF—a protein that is mutated in nearly half of melanomas and drives the cancer’s growth. Both of these drugs will only be helpful to people whose cancer carries the target mutation and that is why the drugs were approved together with a test to determine if an individual person's cancer is likely to be susceptible.
We will see many more such drug–test combinations, and they promise to bring much better results to cancer patients. The approval of these two drugs shows that the era of personalized medicine has begun to arrive.