Placebo effect

From a research point of view, placebos are often essential in determining the safety and efficacy of a treatment. On the other hand, research participants often hope they get active treatment, especially if it is for a disease they already have or might get.

Is it “fair” to research participants to randomly assign them to receive either an active drug or an inactive substance? What about someone with a terminal illness, and the research drug is their last chance? What can be done to make the situation “more fair”?