Using letrozole as maintenance therapy for ovarian cancer

MAintenance Therapy With Aromatase Inhibitor in Epithelial Ovarian Cancer: a Randomized Double-blinded Placebo-controlled Multi-centre Phase III Trial (ENGOT-ov54/Swiss-GO-2/MATAO), Including LOGOS (Low Grade Ovarian Cancer Sub-study).

Phase 3 Interventional Swiss GO Trial Group · NCT04111978

This study is testing if adding letrozole to standard treatment helps women with estrogen-receptor positive ovarian cancer live longer without their cancer getting worse after surgery and chemotherapy.

Quick facts

PhasePhase 3
Study typeInterventional
Enrollment540 (estimated)
Ages18 Years and up
SexFemale
SponsorSwiss GO Trial Group Research network
Drugs / interventionschemotherapy, radiation
Locations53 sites (Graz and 52 other locations)
Trial IDNCT04111978 on ClinicalTrials.gov

What this trial studies

This study evaluates the effectiveness of adding letrozole, an aromatase inhibitor, to standard maintenance therapy for patients with estrogen-receptor positive high and low grade epithelial ovarian cancer after initial surgery and chemotherapy. Participants will be randomly assigned to receive either letrozole or a placebo to determine if letrozole improves progression-free survival compared to standard treatment. The study aims to assess various outcomes, including overall survival and quality of life, using validated questionnaires. A total of 540 eligible subjects will be enrolled in this Phase 3 trial.

Who should consider this trial

Good fit: Ideal candidates are women aged 18 and older with newly diagnosed, histologically confirmed FIGO Stage II to IV estrogen-receptor positive epithelial ovarian, fallopian tube, or peritoneal cancer.

Not a fit: Patients with progressive disease at the end of adjuvant treatment will not benefit from this study.

Why it matters

Potential benefit: If successful, this treatment could significantly improve progression-free survival for patients with estrogen-receptor positive ovarian cancer.

How similar studies have performed: Previous studies have shown positive outcomes with aromatase inhibitors in similar contexts, suggesting potential for success in this approach.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Patients must be ≥ 18 years of age
* Willing and able to attend the visits and to understand all study-related procedures.
* Primary, newly diagnosed FIGO Stage II to IV and histologically confirmed low or high grade serous or endometrioid epithelial ovarian/fallopian tube/peritoneal cancer
* (Interval-) debulking performed ECOG-Performance Status 0-2
* Signed informed consents (ICF-1; ICF-2)
* Paraffin-embedded tissue or paraffin-embedded cell block (from ascites) available
* Positivity (≥ 1%) for ER expression (only determined by Histopathology Core Facility of MATAO trial)
* At least 4 cycles of platinum-based chemotherapy (neoadjuvant allowed)
* Negative serum pregnancy test in women of childbearing potential who will get/have gotten a surgical resection or radiation sterilization, prior to the intervention in the therapeutical maintenance setting.

Exclusion Criteria:

* Progressive disease at the end of adjuvant treatment as defined in chapter 9.2.1 of protocol
* Women of childbearing potential (not having undergone a surgical or radiation sterilization and not getting a surgical resection, prior to the intervention in the therapeutical maintenance setting)
* Pregnant or lactating women
* Any other malignancy within the last 5 years which has impact on the prognosis of the patient
* \< 4 cycles of chemotherapy in total
* Contraindications to endocrine therapy
* Inability or unwillingness to swallow tablets
* Patients with a known intolerance to galactose, lactase deficiency and glucose-galactose malabsorption

Where this trial is running

Graz and 52 other locations

+3 more sites — see ClinicalTrials.gov for the full list.

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Ovarian Neoplasm EpithelialFallopian Tube NeoplasmsPeritoneal NeoplasmsHigh-grade Serous Ovarian CarcinomaLow-grade Serous Ovarian CarcinomaOvarian Endometrioid Carcinomamaintenance therapyaromatase inhibitor
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.