Mesothelioma Clinical Trial Results May Be Skewed by Narrow Inclusion Criteria

Australian researchers say too many mesothelioma clinical trial results are skewed because they do not include enough “real world” patients.  

By “real world patients”, they mean those who fit the profile of the typical mesothelioma patient. The researchers say some of the most important trials limit enrollment to younger people or those with few other health problems. 

They say that leaves out a lot of patients. It also makes mesothelioma clinical trial results less relevant in practice. 

How Clinical Trials Work

Scientists typically test proposed new mesothelioma treatments on isolated cells in a lab first. If the results look promising, they will then run tests in animals to make sure the treatment is safe.  

Before a medicine receives approval for mesothelioma patients, it must go through a series of tests in human patients. These are called clinical trials. Phase I trials help determine the safest effective dose. Phase II trials include more patients and show if the treatment actually works. 

The FDA looks at mesothelioma clinical trial results to decide whether to approve a treatment.  

Two Important Mesothelioma Studies

The authors of the new study looked at the patient criteria for two of the important mesothelioma clinical trials in recent years. Then they considered 133 of their own mesothelioma patients to see if they would have qualified. 

One of the trials was the Mesothelioma Avastin Cisplatin Study (MAPS). In this study, patients took the immunotherapy drug bevacizumab (Avastin) along with standard mesothelioma chemotherapy. Avastin is a VEGF inhibitor. The mesothelioma clinical trial results showed Avastin helps keep mesothelioma tumors from growing new blood vessels. 

The second trial was the KEYNOTE trial. This study evaluated the immunotherapy drug pembrolizumab (Keytruda) for mesothelioma.

Are Mesothelioma Clinical Trial Results Relevant?

Fifty percent of the Australian patients did not meet the criteria for the MAPS trial. Thirty-seven percent were not eligible for the KEYNOTE trial. This was usually because patients were either too old, taking too many medications, or had too many other medical conditions. 

“Only ≤63% of our patients were eligible for these trials, highlighting the differences between real-world patients and the highly select trial population,” writes study author Brandon Lau. 

Dr. Lau says their patients who did participate in one of these studies lived longer than patients who did not. The researchers say these mesothelioma clinical trial results are further proof that the selection process is biased. 

For those who qualify, mesothelioma clinical trials are often the best way to gain access to cutting edge treatments. For a list of ongoing mesothelioma studies and their eligibility criteria, visit ClinicalTrials.gov

Source:

Lau, B, et al, “Clinical Trials Eligibility of Patients With Malignant Pleural Mesothelioma: Use of Novel Therapies and Outcomes”, March 7, 2020, Epub ahead of print, https://www.clinical-lung-cancer.com/article/S1525-7304(20)30007-3/pdf