A Study to Evaluate the Efficacy and Safety of Gefapixant (MK-7264) in Women With Endometriosis-Related Pain (MK-7264-034)
Condition: Endometriosis-related Pain
MeSH terms: Endometriosis
Intervention: Gefapixant; Placebo; Naproxen
Intervention description: Gefapixant tablet 45 mg taken orally; Placebo matching gefapixant tablet taken orally; Naproxen sodium 275 mg tablets taken orally as needed, at dose prescribed by sites' principal investigator
Intervention MeSH terms: Naproxen
Phase: Phase 2
Study type: Interventional
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Enrollment: 187.0
Sex: Female
Minimum age: 18 Years
Maximum age: 49 Years
Healthy volunteers: No

Summary:

      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.
    

Eligibility criteria:

        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.