Breast cancer tops most studied disease list for a third year: report

Breast cancer has remained the most studied disease in clinical trials for the third year in a row, according to an annual report by clinical development and analytics provider Phesi. Solid tumors came in second.

The report was compiled last year from an analysis of 65,749 recruiting clinical trials, the company explained. Although the list was static in the previous two reports, Phesi said that stroke was the third most studied area, moving up from fifth place in 2022. COVID-19 studies fell from second to fourth on the list as the pandemic has continued to wane, and prostate cancer dropped from third to fifth.

The report also found that about one-third of the 115,000 recruiting investigator sites from interventional trials around the world are located in the U.S. That’s as many locations as the next top seven countries combined, Phesi pointed out. 

Overall, the report indicated an increase in trial recruitment covering all of the top five indications last year.

“What has been especially notable is the increase in solid tumor trials—these are likely to be the foundation of innovative cancer therapies, and investment in this area is a promising sign for patients,” Gen Li, Phesi’s president, said in a statement. “Meanwhile, we have seen a marked reduction in investment into COVID-19 therapies in 2023, likely due to there being fewer available patients.”

Li added that the market for COVID-19 therapies is expected to continue its downward trend as the investment appetite falls.

The report also found an increased attrition rate at phase 2 identified by Phesi’s analysis in 2022 continued and could slow the rate new therapies come to market, as well as impacting clinical development with increased costs. In 2023, 28% of clinical trials were canceled during phase 2 compared to the pre-pandemic average rate of about 20%. The company said phase 3 cancelations are also likely to rise in coming years.

“While there was a slight improvement in cancelation rates in the second half of the year, the data indicate that 2024 will pose further challenges to portfolio managers and trial planners,” Li said. “Ultimately, the clinical development industry is beginning to recover from the pandemic, but we can expect the long-term impact to stretch into 2025.”