BACKGROUND AND PURPOSE:

• Oral gonadotropin-releasing hormone (GnRH) antagonists like elagolix and relugolix have shown promise as a medical treatment option for symptomatic uterine fibroids
• Niaz et al. (Journal of Obstetrics and Gynaecology Canada, 2022) assess the efficacy and safety of oral GnRH antagonists in women with symptomatic uterine fibroids

METHODS:

• Systematic review and meta-analysis
• Study inclusion criteria
  • Clinical trials | Observational studies
  • Studies that provided efficacy and safety data in clinical terms (i.e., reduction in menstrual bleeding and discomfort, changes in the size of leiomyoma and uterine volume, etc.)
• Study design
  • Risk of bias in RCTs was assessed
• Primary outcome
  •  Safety and efficacy outcomes as treatment for uterine fibroids

RESULTS:

• 9 RCTs | 3058 women
  • Risk of bias was generally low among the included trials

Relugolix

• Mean change in bleeding and pelvic discomfort score change (from baseline)
  • Relugolix + estradiol/norethindrone acetate (E2/NETA): range –45 to –51.7
  • Relugolix + delayed E2/NETA: range –48.9 to –51.3
  • Placebo: range –16.1 to –18.3
• Mean blood loss reduction
  • Relugolix + E2/NETA: –84.3 mL
  • Relugolix + delayed E2/NETA: range –88.2 to –89.4 mL
  • Placebo: range –15.1 to –23.2 mL

Elagolix

• Least square mean change in menstrual blood loss
  • Elagolix alone: range –184 to –273 mL
  • Elagolix + E2/NETA: range –168 to –198 mL
  • Elagolix + estrogen/progesterone: 216 mL
  • Placebo: range 0.8 to –79 mL

Adverse effects

• Most common: Hot flashes | Night sweats | Loss of mineral bone density
• Overall, treatment well tolerated
• Add-back therapy were associated with lower incidence and lesser severity of hot flashes

CONCLUSION:

• Oral GnRH antagonists, both alone and in combination with estradiol/norethindrone acetate, were effective at improving symptoms of uterine fibroids in premenopausal patients
• The safety of these medications is also well established
• The authors state

Unlike GnRH agonists, which need to be administered systemically and have an initial flare effect before downregulation, oral GnRH antagonists offer promising results and could become the preferred treatment in the future because of their ease of administration

They can be used in patients refractory to other drugs 

Learn More – Primary Sources:

Efficacy and Safety of Oral GnRh Antagonists in Patients With Uterine Fibroids: A Systematic Review

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