Recent study data by the FDA has found that older blood cancer patients (75+) are severely under-represented in clinical trials
Results from the FDA’s first comprehensive examination of clinical trial enrolment in older patients with blood cancers has revealed that patients over 75 are significantly underrepresented. When looking at the occurrence of these conditions, it has recently been found that one in five patients in the US who are diagnosed with blood cancer are over the age of 75, and this figure is expected to grow as the population ages.
The study analysed data from more than 44,000 patients enrolled in clinical trials for blood cancer treatments between 2005 and 2015. Separating these patients into age groups of below 65, 65-74 and over 75 years old, as well as by disease, the researchers then compared enrolment rates to the Surveillance, Epidemiology and End Results (SEER) programme of the National Cancer Institute 2010-2014 data on the occurrence rates of cancer type by age group. By disease, 45% were enrolled in lymphoma treatment trials, while 24% took part in trials for chronic lymphocytic leukaemia treatment, and 22% for multiple myeloma treatment.
It was found that blood cancer patients over the age of 65 tend to be overrepresented in clinical trials for lymphomas, CLL, CML and multiple myeloma compared to incidence of these conditions in that age group. By comparison, patients over 75 accounted for 29% of CML diagnoses, but made up under 4% of clinical trial participants in this disease area. This underrepresentation continued across lymphoma, CLL, and multiple myeloma.
“Until now, there has been very little information about the enrolment of adults with haematologic cancers. Based on our findings, the occurrence of cancer is much higher in adults over 75 years of age compared with the proportion of patients in this age group who enrol in clinical trials,” explained lead study author Bindu Kanapuru, Medical Officer in the Division of Hematology Products, Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research. “With so few patients aged 75 or older enrolled in clinical trials, critical information on the safety and effectiveness of new therapies in this age group is greatly lacking.”
“We weren’t surprised to see that, overall, adults aged 75 years and older were under-represented in clinical trials, as this is common across cancer trials,” Dr Kanapuru continued. “But we were surprised by the magnitude of the gap for this age group, particularly for CML trials.”
According to Dr Kanapuru, there are a variety of causes for this underrepresentation, with patients frequently excluded from clinical trials on the basis of factors such as previous history of cancer, inhibited functionality of the heart, liver, kidneys or other organs, or other co-existing illnesses – all of which occur more frequently in older patients.
“In addition, doctors may hesitate to enrol these older patients because they aren’t sure how they will tolerate investigational medications,” Dr Kanapuru added. “The 75-and-older population is also extremely heterogeneous. You can have one 75-year-old who is very healthy and another person of the same age who is frail and has a lot of co-existing illnesses.”