Repurposing Atovaquone for the Treatment of Platinum-Resistant Ovarian Cancer

September 5, 2025 updated by: Namita Khanna, Emory University

Phase II Clinical Trial Repurposing Atovaquone for the Treatment of Platinum-Resistant Ovarian Cancer

This phase II trial test tests how well repurposing atovaquone works in treating patients with platinum-resistant ovarian cancer. Atovaquone is used for the treatment or prevention of certain infections. Atovaquone is in a class of medications called antiprotozoal agents. It works by stopping the growth of certain types of protozoa that can cause pneumonia. Giving atovaquone may be effective in treating platinum-resistant ovarian cancer and result in improved outcomes compared to standard chemotherapy regimens.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

PRIMARY OBJECTIVE:

I. To determine progression free survival of twenty-eight patients with platinum-resistant ovarian cancer treated with atovaquone.

SECONDARY OBJECTIVES:

I. To determine clinical benefit rate (complete response, partial response or stable disease) at six months.

II. To determine overall survival. III. To quantitate the on-target STAT3 inhibitory effect of atovaquone on STAT3-dependent gene transcription.

IV. To quantitate changes of the tumor immune infiltrate by inhibition of STAT3 with atovaquone.

OUTLINE:

Patients receive atovaquone orally (PO) on study. Patients also undergo computed tomography (CT) and biopsy or paracentesis throughout the study.

After completion of study treatment, patients are followed up for 30 days and then every 6 month thereafter.

Study Type

Interventional

Enrollment (Estimated)

28

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Patients with platinum-resistant, high-grade serous ovarian cancer, defined as disease progression within six months of completion of their last platinum-based chemotherapy
  • Patients must maintain Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1
  • There will be no limitations on number of prior lines of therapy
  • Trial is open to non-English speaking patients
  • Trial is open to patients referred from community practice

Exclusion Criteria:

  • Patients who are < 18 years old
  • Patients who are pregnant or breastfeeding (due to cancer of their reproductive organs, patients enrolled in the trial are unable to conceive)
  • Patients who are incarcerated
  • Patients who are unable to provide consent / lack decision-making capacity

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Treatment (atovaquone)
Patients receive atovaquone PO on study. Patients also undergo CT and biopsy or paracentesis throughout the study.
Procedure: Computed Tomography
Undergo CT
Other Names:
  • CT
  • CAT
  • CAT Scan
  • Computed Axial Tomography
  • Computerized Axial Tomography
  • Computerized Tomography
  • CT Scan
  • tomography
  • Computerized axial tomography (procedure)
Procedure: Biopsy
Undergo biopsy
Other Names:
  • Bx
  • BIOPSY_TYPE
Drug: Atovaquone
Given PO
Other Names:
  • Mepron
  • 566C80
  • BW-566C
  • BW-A566C
Procedure: Paracentesis
Undergo paracentesis

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Progression free survival (PFS)
Time Frame: From initiation of atovaquone to progression or death, assessed up to 1 year
Will be estimated using the Kaplan-Meier method, and a 95% confidence interval for median PFS will be estimated using the Brookmeyer-Crowley approach.
From initiation of atovaquone to progression or death, assessed up to 1 year

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Clinical benefit rate
Time Frame: At 6 months
Clinical benefit rate is defined as complete response, partial response, and/or stable disease at six months. Clinical response will be assessed every 6 weeks for the first 24 months and every 12 weeks thereafter using Response Evaluation Criteria in Solid Tumors 1.1 criteria. Will be estimated as a proportion, with an exact 95% confidence interval estimated using the Clopper-Pearson method.
At 6 months
Overall survival (OS)
Time Frame: From diagnosis to death from any cause, where patients who are alive will be censored at last follow-up date, assessed up to 1 year
OS will be estimated using the Kaplan-Meier method, and median survival will be calculated. A 95% confidence interval will be estimated using the Brookmeyer-Crowley approach.
From diagnosis to death from any cause, where patients who are alive will be censored at last follow-up date, assessed up to 1 year
Incidence of adverse events
Time Frame: Up to 30 days
Safety will be determined according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 5. Frequencies and percentages will be used to summarize safety events.
Up to 30 days

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Emory University

Collaborators

National Cancer Institute (NCI)

Investigators

  • Principal Investigator: Namita Khanna, MD, MSPH, Emory University Hospital/Winship Cancer Institute

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

November 9, 2023

Primary Completion (Estimated)

June 30, 2026

Study Completion (Estimated)

June 30, 2027

Study Registration Dates

First Submitted

August 11, 2023

First Submitted That Met QC Criteria

August 11, 2023

First Posted (Actual)

August 18, 2023

Study Record Updates

Last Update Posted (Estimated)

September 11, 2025

Last Update Submitted That Met QC Criteria

September 5, 2025

Last Verified

September 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • STUDY00005363 (Other Identifier: Emory University)
  • P30CA138292 (U.S. NIH Grant/Contract)
  • NCI-2023-03479 (Registry Identifier: CTRP (Clinical Trial Reporting Program))
  • WINSHIP5782-22 (Other Identifier: Emory University)

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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