Clinical trials in thalassemia: insights from the patient community

Abstract

There is a significant need for a wide range of clinical trials in the area of thalassemia and its related complications; however, the small U.S. thalassemia patient population (n < 1,500) limits trial enrollment and may deter investigators from initiating a U.S. based trial. Results from a survey conducted by the website for the Center for Information and Study on Clinical Research Participation (CISCRP) found that among people who suffer from severe chronic illness, only 6% participate in clinical trials. 1 Recognizing the problems of clinical trial recruitment in general and within the Thalassemia Clinical Research Network in particular, we sought insights from our patient population regarding trials that depend upon the participation of individuals with thalassemia.Although once considered a pediatric disorder, advances in treatment have resulted in an increase in life expectancy for people born with thalassemia. As a result, many patients now live into their 30's and 40's and beyond, and the widespread adoption of chelation therapy and the advent of more recent, easier-to-administer chelation therapies may mean that life expectancy will increase even more. As the number of adult thalassemia patients increases, more patients are potentially available to participate in clinical trials; however, as adults, these patients have greater constraints placed upon the time they have available for trial participation in addition to limited eligibility due to secondary complications.Moreover, changing immigration patterns create changes in the make-up of the thalassemia community. Recent decades have seen a greater influx of individuals from south Asia, southeast Asia, and China; many of the thalassemia patients from these communities have the ␣-thalassemia, rather than ␤-thalassemia variants.Geographic factors also impact the thalassemia community. The Cooley's Anemia Foundation estimates that about half of U.S. patients are seen at a major thalassemia treatment center, and that about half are not. It is assumed that geographic inaccessibility is a major factor for many of those who are not affiliated with a major treatment center.