ImmusanT Gets $40M From Arch, Vatera to Continue Celiac Vaccine Quest

Xconomy Boston — 

ImmusanT has spent years developing an immunotherapy meant to help people with celiac disease tolerate gluten. Today, on the verge of its most substantial clinical test to date, the company has also come up with its biggest round of funding from some well-known backers.

Arch Venture Partners has joined previous ImmusanT backer Vatera Healthcare Partners to lead a $40 million Series C for the Cambridge, MA, company. The cash will back a randomized, placebo-controlled Phase 2 trial of ImmusanT’s celiac treatment, Nexvax2, as well as continuing efforts to develop a diagnostic for the disease. Arch managing director Steven Gillis and former top Celgene dealmaker Tom Daniel, an Arch venture partner, have joined ImmunsanT’s board in conjunction with the financing.

ImmusanT’s immunotherapy is meant to train the immune systems of celiac disease patients to tolerate gluten—a protein found in wheat, barley, and rye—rather than seeing it as a foreign invader and mounting an attack. Those attacks, which occur when immune cells misidentify fragments of the protein, impair the body’s ability to absorb nutrients. This leads to symptoms like abdominal pain, vomiting, and diarrhea, and potentially much more significant problems like osteoporosis or infertility, if left unchecked. Celiac disease affects about 3 million Americans and the only real option for patients is to avoid gluten.

Nexvax2 contains an engineered version of the three gluten fragments that trigger an immune response in most celiac patients. These peptides are supposed to train the immune system to see gluten as food—much in the way allergy shots help the body gradually learn to tolerate an allergen through periodic injections. The company is also developing a blood-based diagnostic for celiac, and a companion diagnostic to help it identify the patients that might best respond to Nexvax2.

Back in 2014 when ImmusanT raised a $12 million round, the company was first planning to begin Phase 2 tests. But ImmusanT has since instead carried out more Phase 1 studies. CEO Leslie Willams says the company has been taking a “methodical approach” to its development plan to find the right dose to test, and identify blood-based biomarkers—cytokines—that spike during an immune response to gluten. The trials it has run so far, including a study that just wrapped up earlier this year, have helped ImmusanT find that by slowly ramping up a dose of Nexvax2, it can eventually administer a high dose of the therapy and no longer see signs that the immune system is fighting the treatment. These studies have also led to a blood-based diagnostic for celiac, which could be an alternative to the “gluten challenge” patients have to undergo for weeks to identify their disease, Williams says. (Here’s more on the diagnostic in Healio.)

This information may help mitigate the risk of further trials, she says, though that will now have to be proven. ImmusanT still doesn’t know whether the treatment can effectively thwart the symptoms patients get after being exposed to gluten, but the company will soon see if it can. In the coming Phase 2 trial, which should begin next year and wrap up in 2019, volunteers with celiac and a specific genetic marker present in a majority of patients with the disease will be given Nexvax2 following a gluten-free diet. The ultimate goal, through this and other tests, will be to see whether periodic Nexvax2 treatment can rewire the immune system to tolerate gluten, enabling patients to then discontinue therapy and start eating with an unrestricted diet.

Here’s more on ImmusanT, celiac, and some of the other efforts to fight the disease.

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