The ethics of placebo-controlled trials--a middle ground

Abstract

[...]without a placebo group to ensure validity, the finding that there is no difference between the investigational and standard treatments can be misleading or uninterpretable.8 ,9 New treatments that are no better than existing treatments may still be clinically valuable if they have fewer side effects or are more effective for particular subgroups of patients.18 However, no drug should be approved for use in patients unless it is clearly superior to placebo or no treatment.