Erica Barnell, MD, PhD, of Washington University School of Medicine, and founder of Geneoscopy Inc, describes the multitarget stool RNA “ColoSense” test and the CRC-PREVENT study that demonstrated its superior sensitivity and specificity in comparison to traditional colonoscopy.
Originally published in GI Oncology Now | November 7, 2023
Why did you found Geneoscopy and develop the multitarget stool RNA “ColoSense” test?
Dr. Barnell: In 2014, when I entered the MD-PhD program, I was deeply involved in developing technology in the microbiome labs at Wash University. During my clinical rotations, I had a pivotal encounter with an individual who was diagnosed with stage 4 colorectal cancer. This encounter made me realize that in a time when we can sequence the human genome in just 24 hours, we should be able to offer alternative solutions for individuals who either cannot undergo a colonoscopy or for whom it does not align with their lifestyle. This realization inspired me to establish Geneoscopy with the goal of leveraging the microbiome research I had been involved in to improve healthcare solutions for individuals, providing them with options that align with their lifestyles and preferences.
Please detail the CRC-PREVENT study. What kind of patients did you enroll, from where were they sampled, and what were ColoSense test samples compared against?
Dr. Barnell: The ColoSense pivotal study, known as CRC-PREVENT, was a cross-sectional prospective pivotal trial designed to support a pre-market approval application to the FDA. This study was unique in how we recruited patients. We utilized social media advertising to reach patients where they are. Once a patient expressed interest and enrolled in the clinical trial, we would send them a stool sample collection kit, which they would use to provide a stool sample. They would then send the sample back to our laboratory. Afterward, we would facilitate their access to a follow-up colonoscopy. We compared the results of the ColoSense test, whether it was positive or negative, with the results of the colonoscopy to assess the test’s sensitivity for colorectal cancer, sensitivity for advanced adenomas, and specificity for detecting no findings on a colonoscopy.
How did you go about identifying your target participants for the ColoSense test on social media?
Dr. Barnell: Our approach to identifying target participants for the ColoSense test on social media was to target a representative cohort of the approximately 150 million average-risk Americans recommended for colorectal cancer screening. We aimed to include typical individuals over the age of 45 in our study. By employing a decentralized recruitment model, we aimed to obtain a more accurate representation of the population in need of colorectal cancer screening. Instead of relying on site-based recruitment, we were able to reach individuals who had no colonoscopy scheduled at the time of enrollment and who had never previously undergone a colonoscopy or noninvasive screening. Our study targeted individuals who may not have been aware of colorectal cancer screening options or who could not undergo invasive procedures like colonoscopies. These are the individuals for whom ColoSense testing is designed, those who may not be familiar with or cannot tolerate traditional screening methods.
What was the success rate among patients enrolled for undergoing the ColoSense test and getting the colonoscopy?
Dr. Barnell: Through our online enrollment process, we engaged with over 275,000 individuals. Out of that large pool, we identified approximately 14,000 individuals who met our criteria as average-risk, asymptomatic individuals over the age of 45. Among these, around 85% successfully provided a viable ColoSense test to our laboratory. Afterward, about 85% of these patients were successfully guided to undergo a colonoscopy.
What did you find in terms of the sensitivity and specificity of ColoSense testing versus colonoscopy?
Dr. Barnell: In terms of sensitivity and specificity, the ColoSense test showed impressive results when compared to colonoscopy. We achieved the highest sensitivity for colorectal cancer at 94.4%, which is a remarkable outcome. Our test also demonstrated the highest reported sensitivity for advanced adenomas, standing at 46%. Furthermore, the specificity of the ColoSense test for identifying no findings during a colonoscopy was 88%. These results indicate that ColoSense is a highly effective noninvasive screening option for colorectal cancer.
How scalable is the ColoSense test to be commonly used as a noninvasive colorectal cancer screening option?
Dr. Barnell: The ColoSense test has been developed with scalability in mind. We have submitted the data from the pivotal study to the FDA as part of a pre-market approval application. Currently, the FDA is reviewing the data, and we anticipate receiving their decision within the next 3 months. Once we receive FDA approval, we plan to launch the ColoSense test commercially, making it available to healthcare providers and patients. We have established a partnership with a large decentralized laboratory, which will allow us to successfully commercialize this test and reach the 150 million Americans who require colorectal cancer screening. The scalability of the ColoSense test makes it feasible to become a widely used noninvasive colorectal cancer screening option.
Do you believe other “decentralized recruitment efforts” based on regulatory guidance should be used for future trials involving population health screening?
Dr. Barnell: I believe that our decentralized recruitment model has the potential to be a game-changer for future population health screening trials. Our approach offers significant advantages in terms of reaching a diverse and representative cohort, addressing disparities, and ensuring that individuals who traditionally have been underrepresented in clinical trials have the opportunity to participate. The success of our model has even prompted the FDA to produce guidance on the use of decentralized recruitment for clinical trials, which highlights its significance. I hope that our experience will serve as an example for other companies and clinical trials to conduct studies with inclusivity and diversity in mind.
Are there any other takeaways from the ColoSense test or CRC-PREVENT that you would like to add?
Dr. Barnell: Another noteworthy takeaway from the ColoSense test and the CRC-PREVENT study is the high sensitivity and specificity observed in the younger age population (ages 45 to 50). This is particularly significant because colorectal cancer screening recommendations now include individuals aged 45 and above. In our study, approximately 22% of the cohort fell within this age group. We observed 100% sensitivity for colorectal cancer and 45% sensitivity for advanced adenomas in this age bracket. This provides robust evidence that ColoSense testing can effectively screen patients in the 45 to 50 age range noninvasively, offering a valuable option for early detection in this population.