The design of clinical trials for cancer drug therapy is changing because of the introduction of "basket" trials, as discussed in a previous note (see: Genetic Testing as a New Cancer Care Standard; Clinical Trials Also Changing). Here's a definition of a "basket" trial copied from that note:
The development of the “basket” trial is one example [of how cancer drug trials are changing]. Instead of starting with multiple clinical trials in different diseases ..., we start with one trial — the basket — and one or more targets, and allow patients with multiple diseases to enroll in cohorts or groups. If one group shows good response, we expand this group to immediately assess whether others could benefit from the new therapy.
Here's another recent article about how basket trials are being used to test for the efficacy of cancer treatments (see: A Faster Way to Try Many Drugs on Many Cancers). Below is an excerpt from it:
Chemotherapy and radiation failed to thwart Erika Hurwitz’s rare cancer of white blood cells. So her doctors offered her another option, a drug for melanoma. The result was astonishing. Within four weeks, a red rash covering her body, so painful she had required a narcotic patch and the painkiller OxyContin, had vanished. Her cancer was undetectable....She is part of a new national effort to try to treat cancer based not on what organ it started in, but on what mutations drive its growth....[T]his spring, a federally funded national program will start to screen tumors in thousands of patients to see which might be attacked by any of at least a dozen new drugs. Those whose tumors have mutations that can be attacked will be given the drugs. The studies of this new method, called basket studies because they lump together different kinds of cancer, are revolutionary, much smaller than the usual studies, and without control groups of patients who for comparison’s sake receive standard treatment.
Researchers and drug companies asked the Food and Drug Administration for its opinion, realizing that if the F.D.A. did not accept the studies, no drugs would ever be approved on the basis of them. But the F.D.A. said it sanctioned them and could approve drugs with basket study data alone. Instead of insisting on traditional studies, said Dr. Richard Pazdur...,the agency will look at the data and ask, “Is the American population going to be better off with this drug than without it?”These are the sorts of studies many seriously ill patients have been craving — a guarantee that if they enter a study they will get a promising new drug. And the studies move fast; it does not take years to see a big effect if there is one at all. In Mrs. Hurwitz’s case, the mutation in her rare cancer is in a gene, BRAF, found in about 50 percent of melanomas but rare in other cancers. She is among dozens of patients with the same mutation, but different cancers, in the new study that gives everyone the melanoma drug that attacks the mutation. Basket studies became possible only recently, when gene sequencing became so good and its price so low that doctors could routinely look for 50, 60 or more known cancer-causing mutations in tumors. At the same time, more and more drugs were being developed to attack those mutations.
This is truly a revolutionary time for the treatment of cancer and many of us will derive benefit from the changes. As noted above, relatively inexpensive gene sequencing of tumors now enables a new understanding of the genetic weaknesses of many cancers that can be exploited by the use of drugs that take advantage of them. In addition, some clinical trials allow mid-course adjustments to more effective therapy for subjects.
Although mentioned at the end of the first paragraph in the excerpt above, one additional point needs emphasis here. In most previous clinical trials, some subjects, the controls, received standard therapy while others received the new drug regimen being tested in the study. With basket trials, all subjects receive treatment that is hopefully better than this standard. This new approach provides more of an incentive for patients to enter trials. By the way, most patients with aggressive cancers not responding to current treatment should at least be considered for entry into such trials.