Background Currently, women diagnosed with high-risk locally advanced cervical cancer are at high risk of recurrence after treatment with concurrent chemoradiation and represent a population with high unmet need.

Primary Objective The primary objective is to evaluate the progression-free survival of high-risk locally advanced cervical cancer patients who have achieved a partial or complete response after chemoradiation after receiving dostarlimab as maintenance therapy.

Study Hypothesis The study aims to demonstrate that the use of dostarlimab, as maintenance therapy, would significantly increase progression-free survival in these patients.

Trial Design ATOMICC trial is a phase II, randomized, open-label, multicenter study to assess the efficacy and safety of anti-PD1, dostarlimab, as maintenance therapy in patients with high-risk locally advanced cervical cancer who have achieved a partial or complete response after chemoradiation. The control arm entails a clinical and radiological follow-up, with no further treatment (current standard of care). ATOMICC trial is an investigator-driven trial sponsored by GEICO (Grupo Español de Investigación en Cáncer de Ovario) and supported by GlaxoSmithKline (GSK).

Major Inclusion/Exclusion Criteria Women aged over 18 years with a biopsy-confirmed squamous cell carcinoma, adenocarcinoma, or adenosquamous carcinoma of the cervix meeting the following staging criteria: International Federation of Gynecology and Obstetrics (FIGO) 2009 stages IB2, IIA2, IIB with pelvic lymph node involvement, FIGO stages IIIA, IIIB, IVA, and any FIGO 2009 stage with para-aortic lymph node involvement are eligible for the trial. All patients must have achieved a partial or complete response after definitive concurrent chemoradiation. Women diagnosed with FIGO stage IVB, having undergone a previous hysterectomy, or having a history of active autoimmune disease will not be considered eligible.

Primary Endpoint Progression-free survival defined as the time from the date of randomization to the date of first disease progression or death due to any cause, whichever occurs first.

Sample Size A total of 132 patients are expected to be recruited in the study, using a 1:2 (control:experimental arm) randomization allocation ratio.

Estimated Dates for Completing Accrual and Presenting Results The trial was launched in Q2-2019 and the trial is estimated to be closed for recruitment in Q3-2022. Results are expected to be released in Q3-2024.

Trial Registration The trial is registered at ClinicalTrials.gov (NCT03833479).