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Swiss GO Trial Group

Gynecological Trials

Here you find the current Swiss-GO trials.
Clinical Trials / Swiss-GO Trials Switzerland   [EN]

MATAO trial for newly diagnosed Ovarian Cancer

MATAO-A clinical phase III trial on the use of letrozole maintenance therapy for newly diagnosed advanced ovarian, fallopian tube or peritoneal cancers.

In Switzerland, every year, around 800 women are diagnosed with ovarian, fallopian tube or peritoneal cancer. The prognosis of patients with advanced ovarian/tubal/peritoneal cancer is poor with over 70% of patients diagnosed with progression within 3 years of initial diagnosis and a 5-year overall survival rate reported varying from 30% till up to 50%, emphasizing the clear unmet medical need for new treatment modalities. A high percentage of the epithelial ovarian cancers express Estrogen Receptor (ER), an ideal target for endocrine therapy. Letrozole, in this respect, has been used for over decade now to treat Estrogen Receptor positive breast cancer and preliminary results demonstrate it can be a potent drug for patients with heavily pre-treated ovarian cancer as well. However, it has not been evaluated for its use in the maintenance setting for ovarian cancer after standard of care till now. The MATAO trial aims to evaluate the use of letrozole in the maintenance setting as additional standard of care for ovarian cancer patients.

MATAO- MAintenance Therapy with Aromatase inhibitor in epithelial Ovarian cancer: a randomized double-blinded placebo-controlled multi-center phase III Trial including LOGOS (LOGrade Ovarian cancer Sub-study) (ENGOT-ov54/Swiss-GO-2)

For patients, specific criteria have to be fulfilled to participate in this trial. If a participation is possible, the patient have a 50 % chance on receiving a well know medication, which can prolong progression free survival after initial treatment. In addition, their quality of life and personal resilience (ability to manage crises) will be monitored. With a participation in a clinical trial, a participant supports the research and enables that other patients can benefit from new scientific findings.

For additional information, please contact the Swiss-GO office or ask your treating physician to contact the Swiss-GO office: This email address is being protected from spambots. You need JavaScript enabled to view it.

This trial has been developed and initiated by the Swiss GO Trial Group, who functions as the lead sponsor in this respect and is supported by the German and Austrian Foundations for gynecological cancers, AGO and AGO-Austria, and is carried as part of the European study group on gynecological cancers (ENGOT):

Every clinical trial has to be registered in a public register before starting patient recruitment. Please find here the link to the MATAO Study at


With the start of 2023, 245 patients had been recruited and 123 randomized into the trial!


The MATAO trial as a whole is supported by peer-reviewed grants and funding from:

The funders (except for the AGO Studiengruppe e.V. Germany) had no role in the planning and design of this trial. There are no conflict of interests. There are agreements and/or contracts with each of the mentioned financial supporters regarding their funding and role within MATAO signed before the study had starting.


Swiss GO Trial GroupGynecological OncologyHospital for WomenUniversity Hospital BaselSpitalstrasse 21CH-4031 BaselSwitzerland

Contact Info

Phone:  +41 61 265 75 00Fax: +41 61 265 93 22 E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Usefull links

SAKK-Die Schweizerische Arbeitsgemeinschaft für Klinische Krebsforschung ENGOT-The European Network for Gynaecological Oncological Trial groups
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