An experimental treatment for endometriosis, a painful gynecological disease that affects about 190 million people worldwide, may one day offer new hope for symptom relief.
Researchers report on February 22 in Science Translational Medicine , monthly injections of antibodies eliminate signs of endometriosis in monkeys. The antibody targets IL-8, a molecule that causes inflammation inside the scattered, sometimes bleeding lesions that mark the disease. The team found that after IL-8 was neutralized, these signs of damage were reduced.
The new treatment is “quite powerful”, says Philippa Saunders, a reproductive specialist at the University of Edinburgh. The study authors did not report the treatment, she notes, but their antibodies appear to have an effect. “I think it’s really promising,” she says.
Many scientists believe that endometriosis occurs when particles of the lining of the uterus, the endometrium, are shed during menstruation. Instead of exiting through the vagina, they travel in the other direction: up the fallopian tubes. These pieces of tissue then travel through the body, sprouting lesions where they enter. They will end up in the ovaries, fallopian tubes, bladder and other places outside the uterus and take on a life of their own, Saunders says.
The lesions can sprout nerve cells, form hard lumps of tissue, and even bleed during the menstrual cycle. They can also trigger chronic attacks of pelvic pain. If you have endometriosis, you may experience “pain with urination, pain with bowel movements, pain with sex, pain with movement,” says Saunders. People with the condition may also struggle with infertility and depression, she adds. “It’s really disgusting.”
Painful symptoms
Endometriosis is a common gynecological condition, but it can take years before people are diagnosed. Here are some symptoms of the disease:
- Painful periods
- Pain during and/or after sex
- Pain during urination and defecation
- Heavy menstrual bleeding or bleeding between periods
- Infertility
- Fatigue
- Diarrhea and/or constipation
- Bloating and/or nausea
Once diagnosed, patients face a dearth of treatment options—there are no cures, only therapies to relieve symptoms. Surgery to remove the lesions can help, but symptoms often return.
The disease affects at least 10 percent of girls, women and transgender men of reproductive age, Saunders says. And people usually suffer for years — about eight on average — before being diagnosed. “Doctors consider menstrual pelvic pain to be very common,” says Ayako Nishimoto-Kakiuchi, a pharmacologist at Chugai Pharmaceutical Co. Ltd. in Tokyo Endometriosis is “underestimated in the clinic,” she says. “I strongly believe that this disease is understudied.”
Hormonal drugs that stop ovulation and menstruation can also help, says Serdar Bulun, a reproductive endocrinologist at Northwestern University Feinberg School of Medicine in Chicago, who was not involved in the new study. But these drugs have side effects and are not ideal for people trying to conceive. “I see these patients day in and day out,” he says. “I see them suffering and I don’t think we’re doing enough.”
Nishimoto-Kakiuchi’s team created an antibody that captures the inflammatory factor IL-8, a protein that scientists previously thought was one of the potential culprits of the disease. According to Nishimoto-Kakiuti, the antibody acts as a garbage collector. It grabs IL-8, delivers it to the cell’s waste disposal machinery, and then sets off to catch more IL-8.
The team tested the antibody on cynomolgus monkeys that had been surgically modified to have the disease. (Endometriosis rarely manifests spontaneously in these monkeys, as scientists previously discovered after screening more than 600 females.) The team treated 11 monkeys with an injection of antibodies once a month for six months. In these animals, the lesions shriveled, and the adhesive tissue that sticks them to the body also thinned. Nishimoto-Kakiuchi says that before this study, the team did not believe that these signs of endometriosis were reversible.
Her company has now begun the first phase of clinical trials to test the therapy’s safety in humans. The treatment is one of several treatments for endometriosis that scientists are testing. Other trials will test new hormone drugs, robotic surgery and behavioral interventions.
Saunders says doctors need new ways to help people with the disease. “There is a huge unmet clinical need.”
