Although the primary goal of a Phase I trial for mesothelioma is to determine the toxicity of a specific drug, how the drug reacts when used in human beings and the appropriate dosage to be used in future trials, these trials are also conducted with therapeutic intent.
Phase I clinical trials are normally limited to less than 30 participants, and these participants are divided into groups of three to six per group. Each individual group is then treated with increasing doses of the drug, with the first group receiving the pre-clinical dosage. If no serious side effects are observed in the initial group after a certain period of time (generally three to four weeks), the second group receives a higher dosage. This is repeated group by group until a percentage of the participants experience side effects undesirable enough that a higher dosage for the next group would be inadvisable. The highest dosage with acceptable toxicity levels is then considered appropriate for further testing.
Almost all Phase I cancer trials involve participants who have been diagnosed with a cancer, such as mesothelioma, that does not necessarily respond well to treatment. In many cases, patients with various types of cancer, may be enrolled in the same trial. In order to be eligible for a Phase I trial, it is generally required that participants have organ function capable of metabolizing and excreting the drug, and a projected life expectancy of at least 1-2 months.
As with all clinical trials, it is important for participants to weigh benefit versus risk. If the investigational drug proves to be effective, the participant may be one of the first to benefit, however, since Phase I trials are usually the first studies involving humans, unanticipated side effects may occur.
Related: The NIH Clinical Trials database