Oral abstract session: Gynecological cancer

In this highlight video from ASCO 2026, Dr Emiel De Jaeghere, medical oncologist in training at Ghent University Hospital, discusses the key highlights from the oral abstract session on gynecological cancer, focusing on five studies that collectively reflected the rapidly evolving treatment landscape in endometrial and ovarian cancer. 

The first study highlighted was the RUBY trial, a landmark phase III investigation evaluating dostarlimab in combination with chemotherapy versus chemotherapy alone in patients with advanced or recurrent endometrial cancer.¹ Investigators presented long-term survival outcomes and mixture cure modeling analyses focused on the mismatch repair-deficient (dMMR) population. With an additional two and a half years of follow-up beyond the previous report, only 4 new progression-free survival (PFS) events were observed in the dMMR cohort. According to Dr De Jaeghere, this finding provides strong evidence for a durable plateau in the survival curve and confirms the existence of a long-term tail of benefit. The mixture cure model estimated that approximately 54% of patients with dMMR disease may ultimately be cured following treatment with dostarlimab plus chemotherapy.¹ These data represent a remarkable development in a disease setting that only a few years ago was universally regarded as incurable. The durability of disease control observed in this molecular subgroup further strengthens the position of immunotherapy as a cornerstone of first-line treatment for advanced dMMR endometrial cancer.

A second important update in endometrial cancer came from NRG-GY018, the pivotal phase III trial evaluating pembrolizumab combined with chemotherapy in the first-line treatment of advanced disease.² Updated OS analyses were presented separately for patients with dMMR and proficient mismatch repair (pMMR) tumors. In the dMMR cohort, outcomes remained highly encouraging. At the four-year landmark analysis, approximately 80% of patients receiving pembrolizumab plus chemotherapy remained alive compared with 60% of those treated with chemotherapy alone (HR[95%CI]: 0.56[0.34-0.92]). In the pMMR cohort, a statistically significant overall survival advantage was not yet demonstrated. Nevertheless, investigators did report a numerical survival improvement approaching one year in favor of the pembrolizumab-containing regimen (median OS: 44.4 vs. 35.1 months; HR[95%CI]: 0.86[0.69-1.08]).² The relatively immature nature of the survival dataset, with only 78% maturity reached, and the fact that more than half of patients received immunotherapy after disease progression may explain the absence of statistical significance at this stage. Further follow-up will be required before definitive conclusions can be drawn regarding the impact of pembrolizumab on OS in the pMMR population.

The discussion then turned to ovarian cancer, beginning with the CHIPRO trial in platinum-resistant disease.³ This randomized phase III study conducted in China investigated the addition of chiauranib to weekly paclitaxel. Chiauranib is an oral multikinase inhibitor with activity against Aurora B kinase, providing both direct antitumor activity and effects on the tumor microenvironment. The trial design incorporated six cycles of weekly paclitaxel, corresponding to 18 weekly administrations, while chiauranib was administered both concurrently and as maintenance treatment following chemotherapy completion. The study demonstrated a statistically significant improvement in PFS, with median PFS increasing from 2.7 months in the control arm to 4.6 months in the chiauranib arm (HR[95%CI]: 0.427[0.34-0.54]). Despite this encouraging efficacy signal, the improvement did not translate into a significant OS benefit.³ This result contrasts with several recent positive studies in platinum-resistant ovarian cancer, including the ROSELLA trial evaluating relacorilant, the MIRASOL study of mirvetuximab soravtansine, and KEYNOTE-B96 evaluating pembrolizumab-based therapy, all of which demonstrated OS improvements. CHIPRO investigators did report a subgroup analysis suggesting an OS advantage among patients who did not receive subsequent therapy after study treatment. However, Dr De Jaeghere emphasized that these exploratory findings should be interpreted cautiously given the inherent limitations of subgroup analyses.

Another noteworthy ovarian cancer presentation was the CHRONO trial, a French randomized phase II study evaluating the timing of interval debulking surgery following neoadjuvant chemotherapy.⁴ Eligible patients had completed three cycles of neoadjuvant treatment and were considered suitable candidates for interval surgery. Participants were randomized either to immediate interval debulking surgery after three cycles of chemotherapy followed by five additional adjuvant cycles, or to a delayed surgery strategy consisting of three further cycles of neoadjuvant chemotherapy, delayed interval debulking surgery, and two adjuvant cycles thereafter. No statistically significant difference in PFS was observed between the two approaches. Equally important, no differences emerged with regard to mortality, severe postoperative morbidity, or quality-of-life outcomes.⁴ These findings add important evidence to an ongoing discussion regarding the optimal timing of surgery in advanced ovarian cancer and suggest that delaying interval debulking surgery in selected patients may not adversely affect clinical outcomes.

The final study that was selected is the MIROVA trial, a German randomized phase II study in platinum-sensitive ovarian cancer. This study evaluated carboplatin combined with mirvetuximab soravtansine followed by mirvetuximab maintenance versus standard carboplatin-based chemotherapy in patients with high folate receptor alpha expression and a disease-free interval of at least three months.⁵ Although the experimental regimen generated a striking improvement in overall response rate, achieving responses in 66.2% of patients compared with 32.8% in the chemotherapy arm, this increased antitumor activity did not translate into a statistically significant PFS benefit (median: 9.8 vs. 9.5 months; HR[95%CI]: 1.0[0.68-1.46]). Safety analyses also revealed increased rates of neuropathy and ocular toxicity in patients receiving mirvetuximab soravtansine.⁵