A Study to Test the Effectiveness and Safety of Fremanezumab on Participants With Fibromyalgia

The primary objective of the study is to estimate the treatment effect of fremanezumab administered subcutaneously (SC) in reducing pain in adult participants with fibromyalgia (FM). A secondary objective is to evaluate the effect of fremanezumab on other efficacy measures, including pain, quality of life, sleep, fatigue, improvement in health, physical functioning, and mood. Another secondary objective is to evaluate the safety and tolerability of fremanezumab administered SC in adult participants with FM.

The total duration of participant participation in the study is planned to be 21 weeks, consisting of a screening period of up to 5 weeks (ranging from 17 to 35 days), and a double-blind treatment period of 16 weeks.


Eligibility Criteria:
Inclusion Criteria:

* approved for study participation by the Fibromyalgia Eligibility Review Committee
* body mass index of 18.5 to 45 kilograms (kg)/square meter (m\^2) and a body weight ≥45 kg
* agree to use only acetaminophen as rescue medication for FM-related pain (up to 1000 mg per dose and not to exceed 3000 mg/day for any indication throughout the study period)
* non-pharmacologic interventions (including normal daily exercise routines, chiropractic care, physical therapy, psychotherapy, and massage therapy) are unchanged for a minimum of 30 days prior to screening and will remain unchanged throughout the study
* agree to maintain a usual and unchanged physical exercise regimen
* must be of nonchildbearing potential or, defined as:

  * women surgically sterile by documented complete hysterectomy, bilateral oophorectomy, or
  * bitubal ligations or confirmed to be postmenopausal (at least 1 year since last menstrual period) and
  * menopausal women confirmed by a follicle-stimulating hormone \>35 units (U)/liter (L)
  * men surgically sterile by documented vasectomy OR

If of childbearing potential, patients must meet any of the following criteria:

* must use highly effective contraception method with their partners during the entire study period and for 5 months after the last dose of the study drug.
* sexual abstinence is only considered a highly effective method if defined as refraining from heterosexual intercourse in the defined period.
* female participants of childbearing potential must have a negative serum beta-human chorionic gonadotropin (β-HCG) pregnancy test at screening (confirmed by urine dipstick β-HCG pregnancy test at baseline).

  * must agree not to participate in another interventional study from the screening period through the end of study (EOS) visit o Additional criteria apply, please contact the investigator for more information

Exclusion Criteria:

* unable or unwilling to discontinue/washout of prohibited medications
* ongoing pain that would confound or interfere with the assessment of the participant's FM pain or require excluded therapies during the participant's participation in this study.
* surgery planned during the study period
* receiving prophylactic treatment for migraine-related disorders, including topiramate, valproic acid, onabotulinumtoxinA, amitriptyline, and nortriptyline
* known history of clinically significant or unstable hematologic, cardiac, or thromboembolic events
* known history of suicide attempt, suicidal behavior, or suicidal ideation within the last 12 months
* lifetime history of any psychotic and/or bipolar disorder
* current, untreated, moderate or severe major depressive disorder and/or anxiety
* known history of hypersensitivity reactions to injected proteins, including monoclonal antibodies (mAbs) and animal venoms, or a history of Stevens-Johnson Syndrome/toxic epidermal necrolysis syndrome o Additional criteria apply, please contact the investigator for more information