With more and more digital health drug development tools (DDT) being used in clinical research I’m increasingly interested in understanding how we can differentiate these tools from status quo “gold standard” measures. What’s a sponsor’s incentive to use something other than the gold standard? Focusing on DDT’s objectivity, reliability, etc are important but I believe that focusing on what’s important to the patient is critical and often overlooked.
With this lens, I was interested in reviewing the FDA’s guidance on “patient-focused drug development: selecting, developing, or modifying fit-for-purpose clinical outcome assessments”. The guidance document outlines a roadmap that sponsors can follow to ensure clinical outcome assessments (COAs) are fit-for-purpose. Before diving into the roadmap it’s helpful to define a few key terms: 1) meaningful aspect of health (MAH), 2) concept of interest (COI), 3) context of use (COU) and finally 4) fit-for-purpose.
Meaningful Aspect of Health (MOA): is defined as a “feeling or functioning in daily life that is important to patients” that can be narrow (e.g. word finding difficulties) or broad (e.g. communication challenges).
Concept of interest (COI): The concept of interest is what the COA measures and can be similar or the same as the meaningful aspect of health. COIs are chosen because they are a MAH and they are expected to demonstrate a clinically meaningful effect with treatment.
Context of Use (COU): The context of use includes the intended target population, mode of collection, frequency, etc.
A COA is considered fit-for-purpose when: 1) the COU is clearly defined, 2) the COI is clearly defined, 3) there is clear rationale and 4) sufficient evidence to justify the rationale. Or put another way, how well does the COA measure the COI in the COU.
That brings us back to the roadmap to patient-focused outcome measurement in clinical trials. It includes 4 steps: 1) understanding the disease, 2) conceptualizing clinical benefits & risks, 3) selecting/developing the outcome measure and finally, if the COA passes the 4 criteria above, 4) the COA is fit for purpose. If those 4 steps are met, then one can construct an endpoint from the COA that reflects a meaningful aspect of health.
This roadmap creates a different way vendors and academics can bring DHTs to market - focusing on what matters to patients, rather than simply competing with gold standard COAs.