Clinical trial outcome measures in cough

Effective therapies for the treatment of cough remain a significant unmet need. However, the development of new therapies relies upon validated tools for cough measurement to demonstrate efficacy in clinical trials. Significant progress has been made in the development of new cough outcome measures in recent years. Symptoms are typically captured by patient-reported outcomes and for cough, the cough severity VAS, cough severity diary and the LCQ have been used most often. As coughing is associated with characteristic movement and sound, objective quantification is feasible, and the VitaloJAK system has been used as the primary end-point in all regulatory trials of novel treatments to date. The development of the P2X3 antagonist, gefapixant, for patients with RCC has afforded the first opportunity in the recent past to present data captured with these cough outcome measures to regulatory bodies making decisions about the approval of new treatments. This chapter focuses on cough outcome measures in the context of clinical trials of novel therapies and discusses recent experiences with some of these end-points in the context of approval of new therapies.