Exclusion of older patients from ongoing clinical trials for hematological malignancies: an evaluation of the National Institutes of Health Clinical Trial Registry

Abstract

Introduction: Cancer societies, research cooperatives, and countless publications have urged the development of clinical trials that facilitate the inclusion of older patients and those with comorbidities. We set out to determine the characteristics of currently recruiting clinical trials with hematological patients to assess their inclusion and exclusion of elderly patients.

Methods: The NIH clinical trial registry was searched on July 1, 2013, for currently recruiting phase I, II or III clinical trials with hematological malignancies. Trial characteristics and study objectives were extracted from the registry website.

Results: Although 5% of 1,207 included trials focused exclusively on elderly or unfit patients, 69% explicitly or implicitly excluded older patients. Exclusion based on age was seen in 27% of trials, exclusion based on performance status was seen in 16%, and exclusion based on stringent organ function restrictions was noted in 51%. One-third of the studies that excluded older patients based on age allowed inclusion of younger patients with poor performance status; 8% did not place any restrictions on organ function. Over time, there was a shift from exclusion based on age (p value for trend <.001) toward exclusion based on organ function (p = .2). Industry-sponsored studies were least likely to exclude older patients (p < .001).

Conclusion: Notably, 27% of currently recruiting clinical trials for hematological malignancies use age-based exclusion criteria. Although physiological reserves diminish with age, the heterogeneity of the elderly population does not legitimize exclusion based on chronological age alone. Investigators should critically review whether sufficient justification exists for every exclusion criterion before incorporating it in trial protocols.

Keywords: Clinical trial design; Elderly; Exclusion criteria; Hematological malignancies.

Figure 1.

Search results and trial selection.

Figure 2.

Time trends for exclusion of elderly overall, and based on age, performance status and organ function. Chi-square tests were used to determine statistical significance; a p value <.05 was considered statistically significant.