ABSTRACT
The purpose of this study is to systematically review clinical trials on pharmacological therapies for rare gynecological cancers and analyze their characteristics. The PRISMA guidelines for systematic reviews were followed and two databases were searched (WHO´s International Clinical Trials Registry Platform and clinicaltrials.gov). The Jadad score was used to assess the methodological quality of completed clinical trials. A total of 212 records, covering trials from 1993 to 2022, were included in the final review. More than half were phase II trials (110; 51.89%) and the status of recruiting was mainly completed (80; 37.74%). There were 26 (12.26%) terminated or withdrawn clinical trials. Just 42.45% of the trials were specific only for rare types of gynecological cancers. The most common type of investigated therapy was chemotherapy (89; 41.98%), followed by targeted therapy (64; 30.19%) and a combination of therapies (23.11%). However, in the last five years there was an increase in trials investigating targeted therapies such as immunotherapy, overgrowth-related and angiogenesis-related therapies. All completed trials except one, had a Jadad score 0-2, indicating low-quality. Thirty-six (45.00%) completed clinical trials had neither posted results, nor publications. Higher quality clinical trials with better reporting of results are needed for rare gynecological cancers.

IMPACT STATEMENT
Despite the increase over the years in the number of trials investigating pharmacological therapies (especially targeted therapies) for rare gynecological cancers, higher quality clinical trials and better reporting of results are needed.

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