A Study to Evaluate the Efficacy and Safety of Gefapixant (MK-7264) in Women With Endometriosis-Related Pain (MK-7264-034)

Merck Sharp & Dohme (MSD)

Status and phase: Completed; Phase 2

Conditions: Endometriosis-related Pain

Treatments: Drug: Naproxen; Drug: Placebo; Drug: Gefapixant

Study type: Interventional

Funder types: Industry

Identifiers

NCT03654326

2018-001098-26 (EudraCT Number)

7264-034

MK-7264-034 (Other Identifier)

Details and patient eligibility

About

The purpose of this study is to evaluate the efficacy, safety, and tolerability of gefapixant (MK-7264) in premenopausal female participants with moderate to severe endometriosis-related pain. The primary hypothesis: gefapixant is superior to placebo in reducing the average daily pelvic pain score (cyclic and non-cyclic, combined) during Treatment Cycle 2.

Enrollment: 187 patients

Sex: Female

Ages: 18 to 49 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• has been surgically (laparoscopy or laparotomy) diagnosed with endometriosis.
• has cyclic AND non-cyclic, moderate to severe endometriosis-related pelvic pain (overall pelvic pain score ≥5 using a 0-10 NRS, with 0 representing no pain and 10 representing extremely severe pain).
• has had spontaneous menstrual cycles before Visit 1.
• has body mass index (BMI) between 18 kg/m^2 to 40 kg/m^2 at Visit 1.
• is not pregnant, not breastfeeding, and agrees to follow the contraceptive guidance.
• must agree to switch from her usual analgesic medication to only that which is permitted in the study.

Exclusion criteria

• history of hysterectomy and/or bilateral oophorectomy.
• has undiagnosed vaginal bleeding.
• has chronic, non-pelvic pain not caused by endometriosis that requires chronic analgesic.
• has a clinically significant gynecologic condition identified in the screening evaluation.
• has a history of anaphylaxis or cutaneous adverse drug reaction (with or without systemic symptoms) to sulfonamide antibiotics or other sulfonamide-containing drugs.
• has a known allergy/sensitivity or contraindication to gefapixant or its excipients.
• has an allergy/sensitivity/intolerance to naproxen sodium (rescue medication) or any contraindication to its use, or has experienced asthma, urticaria, or allergic-type reactions after taking aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs).
• has a history of endometriosis-related pain that was non-responsive to treatment with combined hormonal contraceptives (CHCs), gonadotropin-releasing hormone (GnRH) antagonists, GnRH agonists, progestins, or aromatase inhibitors.
• has a positive urine pregnancy test at any time before randomization.
• has required more than 2 weeks of continuous use of narcotics for treatment of endometriosis-related pain within 6 months of Visit 1.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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187 participants in 2 patient groups, including a placebo group

Gefapixant

Experimental group

Description:

Participants will receive a gefapixant 45 mg tablet twice a day for approximately 8 weeks (2 menstrual cycles). Naproxen sodium 275 mg tablets will also be provided to participants for use as rescue medication for endometriosis-related pain.

Treatment:

Drug: Gefapixant

Drug: Placebo

Drug: Naproxen

Placebo

Placebo Comparator group

Description:

Participants will receive a placebo matching gefapixant tablet twice a day for approximately 8 weeks (2 menstrual cycles). Naproxen sodium 275 mg tablets will also be provided to participants for use as rescue medication for endometriosis-related pain.

Treatment:

Drug: Placebo

Drug: Naproxen