In most Phase I trials the first people in the trial get too low a dose. You don't even know if the stuff works in most cases, and then you get an amount which is almost certainly not enough to make it work even if it does work. If you are hoping for efficacy, you should find out where they are in the dose escalation and make sure you're not first. In addition to determining a treatment's MTD, the investigators will want to know how the human body processes the drug. This is known as the treatment's pharmacokinetics.
Some drugs pass through the body very quickly.
Others are retained in the liver or the kidneys or in fatty deposits. The body's own enzymes frequently metabolize the drug, transforming it into one or more other chemical compounds. These metabolites may themselves exert separate therapeutic or toxic effects. Patients enrolled in Phase I trials can expect many of their bodily fluids to be sampled quite a few times each day for pharmacokinetic analysis. Some experts in the ethics of clinical trials are critical of the conduct of some Phase I cancer trials.