New Benchmarks on Protocol Amendment Experience in Oncology Clinical Trials

The drug development industry’s focus on cancer-related treatments continues to rise, with narrow patient populations and complex procedures increasing the complexity of oncology protocols at an accelerated rate compared to non-oncology drugs. Tufts Center for the Study of Drug Development utilized data from a study investigating the impact of protocol amendments to compare how oncology clinical trials differ from non-oncology and identify opportunities to optimize performance in oncology clinical trials.

Sixteen drug development industry companies contributed data from 950 protocols and 2,188 amendments to a study conducted in 2022 investigating protocol amendments. Analysis compared differences in amendment impact and causes between 249 oncology and 701 non-oncology protocols.

Compared to non-oncology, oncology protocols had a significantly higher prevalence (72.1% and 91.1%, respectively) and number (3.0 and 4.0, respectively) of protocol amendments. Oncology protocols with amendments had significantly lower participant completion rates compared to oncology protocols without amendments, while no significant differences were found among non-oncology. During the COVID-19 pandemic, the study found an increased number of substantial amendments, lower completion rates, and higher dropout rates among oncology protocols compared to before the pandemic.

Efforts to prevent avoidable protocol amendments in the industry have not been effective in oncology, where increasingly complex designs are reflected in difficult to predict cycle times, barriers to recruitment and retention and an increase in protocol amendments.