Phase 2 Study of Experimental Eosinophilic Gastritis and Eosinophilic Gastroenteritis Drug Yields Encouraging Data

According to a press release from Allakos, the Company’s experimental eosinophilic gastritis and eosinophilic gastroenteritis drug candidate AK002 has met all primary and secondary endpoints in a phase 2 study of the drug.

About Eosinophilic Gastritis and Eosinophilic Gastroenteritis

Eosinophilic gastritis and gastroenteritis are rare diseases characterized by the painful inflammation of certain parts of the digestive tract. This pain sometimes accompanies nausea and vomiting, and is triggered by the consumption of food. These conditions are different than food allergies, which can typically be managed by avoiding a certain offending food — eosinophilic gastritis and gastroenteritis can be triggered by any food.

These conditions are both caused by an overabundance of eosinophils (eosinophilia) in certain parts of the gastrointestinal tract. Eosinophils are a kind of white blood cell, and like other immune cells performs a diverse array of functions beyond its proinflammatory and anti-antigen activity.

The conditions’ names suggest where the eosinophilia in question occurs. In eosinophilic gastritis, eosinophilia is limited to the gastric tract. Eosinophilic gastroenteritis, on the other hand, is characterized by eosinophilia in one or more parts of the gastrointestinal tract. Currently, there is no approved therapy for either condition.

About AK002 and the Phase 2 ENIGMA Study

AK002 is an experimental antibody that binds to a protein called Siglec-8. This protein is commonly expressed on the surface of certain immune cells, including eosinophils. Researchers believe that by targeting and binding to Siglec-8 proteins, AK002 can effectively reduce eosinophil counts. By lowering eosinophil counts, researchers hope to minimize the overactive immune response that leads to the inflammation and pain characteristic of eosinophilic gastritis and gastroenteritis.

In Allakos’ phase 2 study of AK002, the Company recruited 14 patients with eosinophilic esophagitis, a form of eosinophilic disease that affects the esophagus.  13 (93%) of these patients enjoyed a significant reduction in their esophageal eosinophil levels, opposed to just 53% of the control group (composed of 9 individuals) that received a placebo. When treated with AK002 over a period of several months, patients in the active arm experienced an impressive 95% reduction in gastrointestinal eosinophil counts, versus a 10% increase in the control group. 69% of patients treated with AK002 in the study met treatment response endpoints — showing what researchers considered to be significant improvement in their status (a 75% reduction in biopsy eosinophil counts and a reduction in “total symptom score”, a numeric representation of the severity of symptoms, of over 30%).

The findings of the study are encouraging. In spite of the results, however, AK002 still has a long clinical road ahead of it. The small size of the participating groups could potentially skew collected data. Further study to confirm or debunk the exciting phase 2 data will likely come in the very near future. However, a final ruling on AK002 is still months, if not years away.


Do you, or does anyone you know live with an eosinophilic condition? What do you think of this exciting clinical data? Share your thoughts and hopes with Patient Worthy!

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