Benefit-Risk Assessment in the Absence of Established Definition of Responders

• Activity Number: 680
• Type: Topic Contributed
• Date/Time: Thursday, August 13, 2015 : 10:30 AM to 12:20 PM
• Sponsor: Biopharmaceutical Section
• Author(s): Amarjot Kaur* and Ziliang Li
• Companies: Merck Research Laboratories and Merck Research Laboratories
• Keywords: Benfit-Risk ; Responders ; NNT ; NNH

Abstract

There are many qualitative and quantitative approaches available for making the benefit?risk assessment of a given investigative treatment or across different treatments. Number needed to treat (NNT) and number needed to harm (NNH) is one of the quantitative approaches for relative assessment of efficacy and safety of a given treatment. The NNT represents the number of subjects who need to receive a treatment for one additional subject to benefit from it, while the NNH represents the number of subjects who must receive the treatment for one additional subject to experience harm. The NNT calculations require the proportion of responders based on a priori definition of some dichotomized response which may or may not be readily available depending upon the type of response and the therapeutic area. For example, the definition of responders is not straight forward for continuous efficacy variables when there is no well?established minimal clinically meaningful response and/or in situations where the baseline value is absent. On the other hand, the NNH calculations require the proportion of subjects with safety events of concern which are readily available as a dichotomized response.