Endometrial cancer (EC) stands as the most prevalent gynecologic malignancy. In the past, it was classified based on its hormone sensitivity. However, The Cancer Genome Atlas has categorized EC into four groups, which offers a more objective and reproducible classification and has been shown to have prognostic and therapeutic implications. Hormonally driven EC arises from a precursor lesion known as endometrial hyperplasia, resulting from unopposed estrogen. EC is usually diagnosed through biopsy, followed by surgical staging unless advanced disease is expected. The typical staging consists of a hysterectomy with bilateral salpingo-oophorectomy and sentinel lymph node biopsies, with a preference placed on a minimally invasive approach. The stage of the disease is the most significant prognostic marker. However, factors such as age, histology, grade, myometrial invasion, lymphovascular space invasion, tumor size, peritoneal cytology, hormone receptor status, ploidy and markers, body mass index, and the therapy received all contribute to the prognosis. Treatment is tailored based on the stage and the risk of recurrence. Radiotherapy is primarily used in the early stages, and chemotherapy can be added if high-grade histology or advanced-stage disease is present. The risk of EC recurrence increases with advances in stage. Among the recurrences, vaginal cases exhibit the most favorable response to treatment, typically for radiotherapy. Conversely, the treatment of widespread recurrence is currently palliative and is best managed with chemotherapy or hormonal agents. Most recently, immunotherapy has emerged as a promising treatment for advanced and recurrent EC.

Importance: Patients with platinum-resistant or platinum-refractory ovarian cancer (PRROC) have limited therapeutic options, representing a considerable unmet medical need.Objective: To assess antitumor activity and safety of intraperitoneal (IP) olvimulogene nanivacirepvec (Olvi-Vec) virotherapy and platinum-based chemotherapy with or without bevacizumab in patients with PRROC.Design, Setting, and Participants: This open-label, nonrandomized multisite phase 2 VIRO-15 clinical trial enrolled patients with PRROC with disease progression following their last prior line of therapy from September 2016 to September 2019. Data cutoff was on March 31, 2022, and data were analyzed between April 2022 and September 2022.Interventions: Olvi-Vec was administered via a temporary IP dialysis catheter as 2 consecutive daily doses (3 × 10⁹ pfu/d) followed by platinum-doublet chemotherapy with or without bevacizumab.Main Outcomes and Measures: Primary outcomes were objective response rate (ORR) via Response Evaluation Criteria in Solid Tumors, version 1.1 (RECIST 1.1) and cancer antigen 125 (CA-125) assay, and progression-free survival (PFS). Secondary outcomes included duration of response (DOR), disease control rate (DCR), safety, and overall survival (OS).Results: Twenty-seven heavily pretreated patients with platinum-resistant (n = 14) or platinum-refractory (n = 13) ovarian cancer were enrolled. The median (range) age was 62 (35-78) years. The median (range) prior lines of therapy were 4 (2-9). All patients completed both Olvi-Vec infusions and chemotherapy. Median follow-up duration was 47.0 months (95% CI, 35.9 months to NA). Overall, ORR by RECIST 1.1 was 54% (95% CI, 33%-74%), with a DOR of 7.6 months (95% CI, 3.7-9.6 months). The DCR was 88% (21/24). The ORR by CA-125 was 85% (95% CI, 65%-96%). Median PFS by RECIST 1.1 was 11.0 months (95% CI, 6.7-13.0 months), and the PFS 6-month rate was 77%. Median PFS was 10.0 months (95% CI, 6.4-NA months) in the platinum-resistant group and 11.4 months (95% CI, 4.3-13.2 months) in the platinum-refractory group. The median OS was 15.7 months (95% CI, 12.3-23.8 months) in all patients, with a median OS of 18.5 months (95% CI, 11.3-23.8 months) in the platinum-resistant group and 14.7 months (95% CI, 10.8-33.6 months) in the platinum-refractory group. Most frequent treatment-related adverse events (TRAEs) (any grade, grade 3) were pyrexia (63.0%, 3.7%, respectively) and abdominal pain (51.9%, 7.4%, respectively). There were no grade 4 TRAEs, and no treatment-related discontinuations or deaths.Conclusions and Relevance: In this phase 2 nonrandomized clinical trial, Olvi-Vec followed by platinum-based chemotherapy with or without bevacizumab as immunochemotherapy demonstrated promising ORR and PFS with a manageable safety profile in patients with PRROC. These hypothesis-generating results warrant further evaluation in a confirmatory phase 3 trial.Trial Registration: ClinicalTrials.gov Identifier: NCT02759588