The Food and Drug Administration (FDA) announce the approval of the commercial version of the drug elagolix for the treatment of endometriosis pain. This is the first time in over a decade that an oral treatment specifically designed for endometriosis pain has been approved.

Endometriosis is a condition affecting around 1 in 10 women in the United States, and around 200 million people worldwide.

The condition is characterized by an abnormal growth of endometrium, which is the tissue that normally lines the inside of the uterus.

This tissue growth causes pain in the pelvis, lower back, and abdomen. Other symptoms include heavy periods or bleeding in-between periods, extremely painful menstrual cramps, pain during intercourse, and infertility.

There is currently no cure for the condition, but surgery is often recommended to remove the tissue, which relieves the symptoms for a while. Birth control pills are often prescribed to slow down the growth of abnormal tissue, and nonsteroidal anti-inflammatory drugs such as ibuprofen help ease the pain.

Now, the FDA has approved a new drug to ease the pain of women living with moderate to severe endometriosis.

Elagolix is "the first and only oral gonadotropin-releasing hormone [...] antagonist" designed specifically for endometriosis.

The drug—which will be marketed at the beginning of August this year under the brand name Orilissa—is the first of its kind to have been approved by the FDA in more than a decade.

Drug relieves pain in largest clinical trial yet

The drug was approved based on the results of two studies that formed the largest phase 3 clinical trial program to have ever been conducted on endometriosis.

In total, the studies examined the effects of elagolix on almost 1,700 women who had moderate to severe endometriosis pain.

In the two studies, the women were administered either 150 mg of elagolix once daily or 200 mg twice daily.

Compared with the women who received placebo, those who received the treatment reported a significant reduction in three types of pain: nonmenstrual pelvic pain, menstrual pelvic pain, and pain during intercourse.

These results were noted at 3 months and 6 months from the beginning of the treatment.

The FDA approved the following recommended dosage and duration of use: the drug can be taken for up to 24 months in a dosage of 150 mg per day, or up to 6 months if the dose is 200 mg twice per day.

However, the clinical trials also revealed a range of side effects. The most common ones were hot flashes, night sweats, headache, nausea, trouble sleeping, anxiety, joint pain, depression, and mood swings.

The biopharmaceutical company AbbVie funded the clinical trials. Dr. Michael Severino, the vice president of the company, comments on the FDA approval, saying that it "represents a significant advancement for women with endometriosis and physicians who need more options for the medical management of this disease."

First study author Dr. Hugh S. Taylor—the chair of the Department of Obstetrics, Gynecology and Reproductive Sciences at the Yale School of Medicine in New Haven, CT—also weighs in, saying, "Endometriosis is often characterized by chronic pelvic pain that can impact women's daily activities."

"Women with endometriosis may undergo multiple medical treatments and surgical procedures seeking pain relief and this [FDA] approval gives physicians another option for treatment based on a woman's specific type and severity of endometriosis pain."

Dr. Hugh S. Taylor