Last reviewed · How we verify
Add-back
Add-back is a progestin (norethisterone acetate) co-administered with a GnRH agonist to mitigate hypogonadal side effects while maintaining the therapeutic benefits of GnRH suppression.
Add-back is a progestin (norethisterone acetate) co-administered with a GnRH agonist to mitigate hypogonadal side effects while maintaining the therapeutic benefits of GnRH suppression. Used for Endometriosis (as add-back to GnRH agonist therapy), Uterine fibroids (as add-back to GnRH agonist therapy).
At a glance
| Generic name | Add-back |
|---|---|
| Sponsor | ObsEva SA |
| Drug class | Progestin (add-back therapy component) |
| Target | Progesterone receptor |
| Modality | Small molecule |
| Therapeutic area | Gynecology / Reproductive Health |
| Phase | Phase 3 |
Mechanism of action
In endometriosis and uterine fibroids, GnRH agonists suppress estrogen production but cause menopausal symptoms and bone loss. Add-back therapy uses low-dose progestin to restore some hormonal activity, reducing vasomotor symptoms and bone density loss while preserving the disease-suppressive effects of GnRH agonism. This approach improves tolerability and allows longer treatment duration.
Approved indications
- Endometriosis (as add-back to GnRH agonist therapy)
- Uterine fibroids (as add-back to GnRH agonist therapy)
Common side effects
- Headache
- Breast tenderness
- Mood changes
- Weight gain
Key clinical trials
- Effect of Kinesio Taping Application in Addition to Pilates Exercises on Core Muscle Thickness, Cognition and Mental Fatigue in Individuals With Non-specific Low Back Pain (NA)
- IASTM and Vibration Effects on Pain, Functionality, and Kinesiophobia in Lumbar Disc Herniation (NA)
- Exercise and Mindfulness in Patients With Non-specific Chronic Low Back Pain: The BACKFIT Project (NA)
- Effects of Dual Task-Oriented Circuit Training on Walking Recovery in Sub-acute Stroke (NA)
- Testing the Addition of an Immunotherapy Agent, Atezolizumab, When Given With the Usual Chemo-Immunotherapy Drug Combination (Rituximab Plus Gemcitabine and Oxaliplatin) for Relapsed/Refractory (That Has Come Back or Not Responded to Treatment) Transformed Diffuse Large B-Cell Lymphoma (PHASE1)
- Examining the Effectiveness of Exercise Training After Cervical Laminoplasty Surgery (NA)
- The Effect of Core Stabilization Exercises Applied With Virtual Reality-Based Telerehabilitation in the Treatment of Chronic Low Back Pain (NA)
- Bilateral Cervical Plexus Block for Postoperative Pain After Thyroidectomy (NA)
Primary sources
Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.
| Source | Used for |
|---|---|
| ClinicalTrials.gov | Trial enrolment, design, endpoints, results |
Competitive intelligence
For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:
- Add-back CI brief — competitive landscape report
- Add-back updates RSS · CI watch RSS
- ObsEva SA portfolio CI