Corneal Confocal Microscopy: a Surrogate Endpoint for Neurodegeneration in Clinical Trials


Challenges in Clinical Trial End-points for Peripheral Neuropathies: Lessons from CIDP

Clinical trial end-points are critical to the success of drug development of new therapies. Choosing the wrong end-point can result in the apparent failure of a new drug when in fact the drug might be valuable. This is particularly difficult in peripheral neuropathies where there are few approved drugs but many diseases with high unmet medical need. In peripheral neuropathies where the changes are rapid, picking a trial end-point is not difficult as successful drugs will positively impact almost any outcome measure chosen. Examples of these include GBS, CIDP and MMN. In other disorders, the treatment is wildly successful, and  about any outcome measure will show a positive result. An example of this is Familial Amyloid Polyneuropathy (hATTR). The more difficult are the slowly changing neuropathies including diabetic polyneuropathy and Charcot-Marie-Tooth disease.  Much time and expense have been devoted to clinical trial endpoints in those diseases and so far there are no approved drugs for either disease. The standard endpoints have not been responsive. In fact for many endpoints to date, they do not show much change over the length of a rationale clinical trial, 12-24 months. Thus much attention has turned to “surrogate” markers of disease such as CCM.