In addition to a vaccine, ImmusanT is creating diagnostic screening tests for celiac disease. Its whole-blood ELISA test measures the activity of T cells that cause celiac disease. Diagnostic blood tests will be used to select patients who are most likely to respond to the vaccine and to monitor their response to treatment. Most celiac disease patients carry the HLA-DQ2 gene, but their symptoms vary. For example, some patients do not have gastrointestinal symptoms, but instead suffer from skin disorders.
“A diagnostic test based on functional T cells will identify subpopulations of patients in whom our immunotherapeutic will be effective,” says Williams. Then patients receiving Nexvax2 will be monitored to evaluate the effectiveness of the dosing schedule.
The diagnosis of celiac disease now requires an endoscopic biopsy in order to take multiple tissue samples from the small intestines. A stand-alone diagnostic tool could potentially replace invasive biopsies as a definitive diagnostic. The company also has a commercial agreement with Inova Diagnostics to develop improved serology diagnostic screening tests for celiac disease. “It takes about nine years before a patient with symptomatic celiac disease receives a diagnosis. We want to shorten that time with better diagnostics,” says Williams.
ImmusanT is building a suite of diagnostic and therapeutic tools similar to those used to control other allergies. Allergy patients are first challenged with skin tests to identify immune responses to a particular allergen, then they are treated with injections of the same allergen. “In our case, it's a different type of immune response—the right T-cell response—that makes patients eligible for the vaccine,” says Dr. Anderson.
A few other companies are working on therapies for celiac disease, but they differ in the targets under attack. “We focus on the heart of the disease, the immunologically induced inflammation triggered by the ingestion of gluten,” says Williams. Competing approaches involve proteases that break down gluten, used in conjunction with a gluten-free diet, or targeting tight junctions in the intestinal wall to block damage.
“We have a unique position because we know how the peptides drive the disease, and we hold a robust intellectual property position based on that knowledge,” explains Dr. Anderson.