Allowing innovative stem cell-based therapies outside of clinical trials: ethical and policy challenges.

This paper discusses exceptional circumstances under which patients outside of clinical trials are likely to receive innovative stem cell-based interventions. These circumstances involve: (1) stem cell interventions not initially amenable to a clinical trials approach; (2) expanded access to investigational stem cell products ("compassionate use"); and (3) off-label uses of FDA approved stem cell products. This paper proposes a new approach to regulating these exceptional cases.