Treating autoimmune diseases with eggs from a pig parasite
Sufferers of autoimmune diseases such as rheumatoid arthritis, Crohn’s disease, or psoriasis are constantly on the lookout for new treatments that can ease their debilitating symptoms. If these individuals were told that swallowing the eggs of a pig parasite could lessen their suffering, many would give it a try. Coronado Biosciences Inc. (Burlington, Massachusetts) is developing what it hopes will be a new class of treatments for autoimmune diseases.
Each dose of the drug contains thousands of microscopic parasite eggs, which are obtained from pig feces. They are suspended in a tablespoon of saline solution and then swallowed. In pigs, the eggs would develop into mature whipworms and reproduce, without harming their host. However, in humans, the same eggs survive for about two weeks. During that that short period, they can modulate a patient’s immune system and prevent it from attacking the body’s own tissues and organs. The company plans to enroll 220 patients with Crohn’s disease in a mid-stage clinical trial. The study participants will receive either a dose with 7,500 eggs from a pig whipworm or a placebo once every two weeks for 12 weeks. In addition, Coronado’s partner, German pharmaceutical manufacturer Dr. Falk Pharma GmbH, is conducting a mid-stage trial of the drug, known as Trichuris suis ova (TSO), in Europe. The two companies plan to share their results when filing for marketing approval in 2016 or 2017.
Coronado Biosciences Inc. is a small startup company, which went public on the Nasdaq stock exchange last December. If the company, which also has an early-stage cancer drug in development, succeeds with TSO, it will compete against multibillion-dollar drugs from companies such as Amgen Inc. and Abbott Laboratories. Market research firm BCC Research predicts that sales of autoimmune disease drugs will grow in the mid-single-digit percentages through 2016, from $34 billion in 2010.
Dr. Joel Weinstock, chief of gastroenterology and hepatology (study of liver diseases) at Tufts-New England Medical Center in Boston, is an adviser to Coronado. The technology behind Coronado’s product was developed by Dr. Weinstock and researchers at the University of Iowa, where Dr. Weinstock was affiliated before he was transferred Tufts. It is based on the “hygiene hypothesis,” which theorizes that many developed countries have, in some ways, become too clean for their own good. Millions of organisms, including viruses, bacteria and worms, enter the body through contact with dirt. Many scientists believe many of these organisms are needed to train the body’s immune system to recognize and fight disease. However, in developed nations, contact with these organisms is minimized via a variety of antibacterial soaps, detergents and sanitizing gels. Studies have shown that the incidence of autoimmune disease tends to be highest in the developed world, and is highest there among upper-income groups. Dr. Weinstock and other researchers theorize that the elimination of certain intestinal parasites may have led to the loss in some individuals of a key mechanism for modulating the immune system.
Standard treatments for autoimmune disorders include injectable drugs that block a protein known as tumor necrosis factor. They include Amgen’s Enbrel and Abbott’s Humira. These depress the immune system, which can reduce the symptoms of autoimmune diseases. However, these drugs increase the risk of serious infection, including tuberculosis, and some types of cancer. Thus, Coronado feels that acceptance of their new drug will be high because of its lack of potential serious side-effects. Furthermore, because the whipworm eggs survive only two weeks, there is no permanent infection.