Mainz Biomed CEO discusses stool test for colorectal cancer vs Galleri blood test

In an interview with Biopharma Reporter, Mainz Biomed CEO Guido Baechler explains how his company’s stool test for colorectal cancer compares with well known, multicancer blood tests like Galleri. 

Early detection blood tests such as Grail’s Galleri typically involve isolating DNA from the blood and deploying machine-learning algorithms to scan the DNA for early signs of cancer. They have often made the headlines for their potential in the mission to catch cancer cases early. Galleri, for example, is being tested​ in around 140,000 volunteers in the UK aged from 50 to 77 to see if it can reliably detect cancer in these volunteers.

However, these blood tests can be pricey, with Galleri’s list price being $949. This would lead to eyewatering costs if used on a population scale.

“Blood tests for multiple cancers work great, but there's a huge cost in terms of the price of the test and how much it costs to follow up,” said Guido Baechler, CEO of the German diagnostics developer Mainz Biomed. These tests are also not so good at detecting which cancer a patient has, which can lead to even more follow-up costs and stress for the person being tested, he added.

Checking the stool

An alternative approach to detecting cancer early is the use of specific tests for the type of cancer in question. In the case of colorectal cancer, the chosen indication of Mainz Biomed, colonoscopy is the traditional approach​ for diagnosing the condition, but can miss potential signs of cancer. But there are other ways to flag up warning signs: such as tests of a patient’s stool sample.

One effective approach stool test is known as multitargeted stool DNA test with fecal immunochemical testing (MT-sDNA or FIT-DNA). These tests screen for abnormal DNA and hidden blood in the stool, which are potential signs of cancer developing. One example is Cologuard, which was approved by the US FDA in 2014.

Like Cologuard, Mainz Biomed’s flagship product ColoAlert is designed to detect early signs of colorectal cancer in stool. Using mRNA biomarkers and artificial intelligence (AI)-based algorithms, ColoAlert is designed to be used with a smaller stool sample than that of ColoGuard and have a lower price than other detection tools. The test is also distributed as a kit that can be processed by many laboratories around the world, making it easier to use than services requiring a central lab.

“Our concept is cool and simple. It potentially will have a much lower cost than other early detection systems and more accessible for underserved communities,” Baechler said.

Sensitive and specific

Earlier this year, Mainz Biomed announced promising results​ from a study for ColoAlert, reporting a sensitivity for colorectal cancer of 92% and a specificity of 90%. In addition, the test was able to pick up advanced adenoma – lesions in a pre-cancerous stage – with a best-in-class sensitivity of 82%, according to the release.

These results, taken from almost 700 samples, were big for Mainz Biomed because they backed up previous findings and held even when tested on different sample types from different regions, underscoring the test’s potential in different populations, said Baechler.

The company had showcased the latest results at the recent ASCO conference to discuss the data with key opinion leaders, advisors, and its clinical research organization to plan the next steps, said the CEO. ColoAlert is now set to enter a pivotal trial by the end of 2024 with US FDA approval expected in 2026 or 2027, he said.

“You see a lot of companies focus on the US because it's a bigger market, and it's simpler to actually grow the market than in Europe,” Baechler said.

The global colorectal cancer screening tests market was worth $1.25 billion in 2023 and is expected to balloon by 7% per year up to 2033, with growth fueled by the development of new testing devices, according to GlobalData​.

In the coming decade, AI could boost the detection of colorectal cancer, said the exec. For example it could improve colonoscopy quality control and accuracy by helping identify missed polyps, and help scientists to develop better biomarkers and algorithms for detecting cancer, he said.

And for the time being, stool tests have the lead on blood tests for finding colorectal cancer before it spreads.

“Would you want to do a stool test that may prevent you from having cancer? Or would you want to wait and do a blood test that only tells you that you already have cancer?” Baechler said. “If you asked me, I would want a test that helps me prevent cancer.”