BALTIMORE – As part of its growing emphasis on its T-cell assay franchise, Adaptive Biotechnologies has taken a step forward in the gastrointestinal autoimmune disease diagnostics market with early exploratory data on immune signatures associated with inflammatory bowel disease.
At the Congress of European Crohn's and Colitis Organisation (ECCO) meeting in mid-February, Adaptive presented a study where the company identified and characterized promising T-cell receptor sequences linked to Crohn's disease that could potentially be harnessed for T cell-based clinical diagnostics and treatment for CD patients.
The study, also published in January in the Journal of Crohn's and Colitis, leverages Adaptive's ImmunoSEQ platform, an immune repertoire sequencing method that can profile T- or B-cell receptors in samples. ImmunoSEQ is Adaptive's "bread and butter technology," said Adaptive's chief medical officer, Lance Baldo, who considered the study as "a great first step" in demonstrating the clinical potential of T cells in informing IBD diagnosis, prognosis, and drug development.
"The entire area of inflammatory bowel disease is an area of very high unmet medical need," Baldo said, noting the aim of this study, which Adaptive has been working on for "a number of months," was to see if there was an association between certain T cells and Crohn's.
In the study, researchers led by Matthieu Allez, professor and head of the gastroenterology department at Hospital Saint-Louis in Paris, sequenced T-cell receptors, or TCRs, from blood samples of 1,738 CD patients from Germany and almost 5,000 control participants from Germany, Italy, and the US.
Baldo said many controls included in this study were obtained from past participants for previous Adaptive studies who gave permission to reuse the data. As for experimental samples, he said the company deployed "a group of people that essentially scours the world" to find institutions with "very large datasets in biobanks" of desired sample types to collaborate with, such as the ones in this study.
In addition to healthy controls, this study also included 715 ulcerative colitis patients from Germany "to make sure that what we were picking up was actually Crohn's disease, and not actually also the colitis," Baldo said.
The analysis revealed 1,121 TCRs that were statistically enriched in CD cases. Termed enhanced sequences, or ES, Baldo said these signals could indicate "a strong contribution of T cells, either reacting to the disease or perhaps being involved in the underlying etiology of disease."
The researchers further validated the ES signals with both blood samples and intestinal biopsy samples from a cohort of more than 430 French CD patients. Paired blood and tissue analysis showed a median of 14 percent shared ES, lending "a lot more credibility and credence" to these TCRs' CD contributions, Baldo said. Furthermore, the study demonstrated that some of the TCRs were associated with class II HLA alleles, and that TCRs could be indicative of ileal or ileocolonic disease location as well as stricturing or fistulizing phenotypes.
With the "immune fingerprint" identified in this study, Baldo said the long-term vision for Adaptive is to devise a test that can not only diagnose IBD but also distinguish different IBD subtypes, say UC or CD, or even further tease out the phenotypes within each subtype to inform a patient's disease profile, treatment plan, and drug development. That said, during its fourth-quarter and full-year 2021 earnings call last month just prior to the ECCO presentation, Adaptive CEO Chad Robins announced that the company plans to launch an IBD assay as part of its T-Detect portfolio in 2023.
The proposed T-Detect IBD test will arrive after Adaptive's T-Detect COVID, which the company launched in early 2021 and for which it subsequently obtained US Food and Drug Administration Emergency Use Authorization and Medicare coverage; and T-Detect Lyme, poised to debut this year during the Lyme disease season.
Based on the launch and market for T-Detect COVID, Baldo anticipates T-Detect IBD will similarly target both consumer patients as well clinicians, including GI specialists and primary care doctors. However, he said Adaptive is "not quite prepared" to discuss a price tag or potential insurance reimbursement, pointing out that the firm is still waiting for "fully fleshed out product performance and [to] see how it compares to standard care."
That said, Baldo emphasized that its IBD testing remains in the "research setting" for now, as more signal optimization and clinical validation are still needed. Baldo said the next step for Adaptive is "to get more samples in house to be able to not only confirm the signal but [also] refine the signal." In addition, he said, the company is also exploring the possibility of a prospective study as well as linking the results with real-world data to better understand outcomes and prognosis.
For that, Baldo said Adaptive has designed a protocol for a future clinical trial, but the company has not initiated the trial with the FDA since it is still "working through the operational aspects."
After all, he said, this study is just "a step along what's intended to be a very long journey to interrogate and investigate the inner workings of the adaptive immune system."