Quinagolide: Investigational Drug May Relieve Endometriosis Pain

Last updated: January 2020

According to the Endometriosis Research Center (ERC) a new, non-hormonal medical therapy is being investigated for the potential treatment of endometriosis pain.1

Quinagolide has received approval outside the US, including in Canada and Europe. It is prescribed to treat high levels of the hormone prolactin (hyperprolactinemia). Quinagolide is a non-ergot-derived selective dopamine D2 receptor - also known as a dopamine agonist. It stimulates dopamine receptors, a brain chemical that sends signals through nerve cells.

Quinagolide is marketed under the brand name Norprolac. It is sold by Ferring Pharmaceuticals, a Swiss drug company. Currently, it comes in tablet form and is taken by mouth.2

Limited treatment options

Endometriosis is a global condition, affecting an estimated 176 million women around the world.1 Women with endometriosis are often misdiagnosed or receive less than adequate care. Currently, commonly used medications can only relieve symptoms; They do not treat the underlying problem.2 There is no known way to prevent or cure endometriosis. Diagnosis can only be confirmed by surgery.

The drugs often prescribed to manage endometriosis pain typically suppress the hormone estrogen. Many of these drugs can have significant side effects and are also expensive.2

Early studies of quinagolide resulted in an acceptable safety profile. It was found not to affect pregnancy or fetal development like some other endometriosis drugs.

The RAQUEL study

A clinical trial called The RAQUEL Study, refers to Randomized Trial Assessing Quinagolide Vaginal Ring for Endometriosis-related Pain. This is an ongoing Phase II clinical trial that is still enrolling participants.3

The study is randomized, double-blind. It is designed to evaluate the efficacy of three different doses of quinagolide on the reduction of moderate to severe endometriosis-related pain compared to placebo.1,3

Other areas of to be evaluated in the study include dysmenorrhea (painful periods), non-menstrual pelvic pain, dyspareunia (pain during sex), vaginal bleeding, quality of life, painkiller use, hormone levels, blood and urine tests, and heart exams.

Study details

This new treatment for endometriosis may be used alone or in combination with surgery (to get rid of any remaining microscopic disease). If successful, this treatment could lower the rate of disease recurrence.2

Recruitment information for this study is available through ClinicalTrials.gov. Participants will receive vaginal rings (in one of three doses) that have been formulated with an extended-release form of quinagolide, or placebo.2 The estimated enrollment is 280 participants. The study will last for 8 menstrual cycles per participant.3 The study began in November 2018 and is scheduled for primary completion in November 2021.

Study information can be found through these resources:

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