Photo: Nielsen Fernandez-Becker, MD, PhD, and Stanford Health Care at 420 Broadway St, Redwood City, CA

By Jennifer Iscol

Can an innovative new investigational drug from Bay Area-based Protagonist Therapeutics prevent gluten from causing an immune response in people with celiac disease? A new clinical trial initiated by Dr. Nielsen Fernandez-Becker, director of the Celiac Disease Program at Stanford Health Care, is seeking participants to aid in this exciting research.

The science behind this drug

The drug, named PTG-100, was previously studied for treating inflammatory bowel disease (IBD). Dr. Fernandez-Becker initiated the current study to test the safety and effectiveness of PTG-100 for treating celiac disease. The drug is targeted at blocking immune cells from entering the intestines, which could reduce or prevent the harmful immune response that characterizes this lifelong condition. 

As part of the phase 1B clinical trial of PTG-100, Dr. Fernandez-Becker is collaborating with the Mark M. Davis Lab at Stanford Medicine in order to better understand the disease process, with the goal of identifying the timing of when a type of white blood cells known as T cells becomes involved in the immune response.

How the clinical trial will work

Dr. Fernandez-Becker and her colleagues are seeking 30 adult participants for the clinical trial. The trial requires a “gluten challenge.” Participants will consume 2-3 grams (about a tenth of an ounce) of gluten daily for six weeks. Therefore, eligible participants may be those who tend to have relatively mild symptoms or are asymptomatic and can tolerate the challenge. Of course, safety protocols protect volunteers from continuing in the trial if they are not tolerating the treatment or the challenge. Participants will be compensated $75 per completed visit. They need to live close enough to visit Stanford Hospital and Clinics in Redwood City, California, seven times during the course of the trial. 

After consenting to be in the study and being screened for eligibility, participants will be divided randomly into two groups, of which one will receive the drug and the other will receive a placebo in a ratio of 2:1 (that is, participants are more likely to receive the drug, as only one third receive the placebo). PTG-100 is taken as a pill for this trial and works primarily in the intestines. Based on previous PTG-100 clinical trials, serious adverse reactions to the drug are unexpected, but there are risks, discomforts, and inconveniences associated with any research study.

Why a non-dietary treatment is needed

It’s important to develop new, alternative treatments for celiac disease. While the gluten-free diet alone is an effective therapy for some celiac disease patients, many have ongoing symptoms and some do not improve on the gluten-free diet at all, developing serious and even life-threatening symptoms in rare cases. Maintaining a strict, medically prescribed, gluten-free diet also has profound daily impacts on the lives of adults and children living with celiac disease. 

How this drug is different

So how does this approach differ from other candidates in the celiac drug development pipeline you may have heard about in recent years? Dr. Fernandez-Becker explained that one category of drugs breaks down gluten to prevent it from activating the immune cells. A second type of approach induces tolerance; that is, it trains the body to accept gluten. In contrast, PTG-100 works by blocking “trafficking,” which means that immune cells cannot migrate from the blood to the intestines where they contribute to the immune response. 

In addition to participating in an important clinical trial for celiac disease, study volunteers will be contributing to significant scientific knowledge about autoimmunity in a way that will help scientists develop targeted therapies in the future.

Learn more

If you’d like to learn more about the clinical trial and consider participating, please contact Aubrey Adiao at (650) 721-3177 or They look forward to receiving your inquiry. 

View details of the PTG-100 study on

Note: This article is provided as a public service. We have no financial relationship with this study.