Clinical trials: two arms are better than one
The German Institute for Quality and Efficiency in Health Care (IQWiG) has responded critically to a reflection paper by the European Medicines Agency (EMA) on the approval of new drugs based on single-arm studies. The EMA correctly points out that studies without a control arm are subject to bias and that, in general, it is hardly possible to estimate causal effects from them. However, it does not provide clear criteria for limiting drug approval based on such studies to extremely rare exceptional cases.
The FDA shows how to do it
There is also no recommendation on external controls - in contrast to guidance published ...











