ESGO 2026 takeaways: Emerging insights shaping the future of endometrial and ovarian cancer treatment
ESGO 2026 takeaways: Emerging insights shaping the future of endometrial and ovarian cancer treatment
The ESGO 2026 Congress concluded last week, bringing together the global gynecologic oncology community to discuss the next wave of clinical data and strategic perspectives.
Two discussions stood out as particularly thought-provoking for companies developing therapies in gynecologic cancers:
- The role of PARP inhibitor maintenance in 1L endometrial cancer under renewed scrutiny
Updated overall survival data from the RUBY Part 2 trial sparked significant discussion at the congress. The study evaluated Jemperli (dostarlimab) + carboplatin/paclitaxel induction followed by dostarlimab ± niraparib maintenance versus chemotherapy followed by placebo maintenance in 1L endometrial cancer. The data update at ESGO 2026 showed no clear OS benefit versus placebo maintenance in the ITT population or the pMMR subgroup. Previously, RUBY Part 2 demonstrated meaningful PFS benefit (SGO 2024) in both the ITT population (mPFS 14.5 vs 8.3 months; HR 0.63) and the pMMR subgroup (mPFS 14.3 vs 8.3 months; HR 0.60).
This outcome has prompted renewed debate across industry and KOLs regarding the role of PARP inhibitor maintenance in endometrial cancer, particularly in pMMR disease, where treatment benefit from immunotherapy alone has historically been modest.
In terms of future outlook, a key hypothesis emerging from ESGO discussions is that molecularly defined subgroups, such as TP53-mutant tumors, may derive greater benefit from PARPi, consistent with signals previously observed in DUO-E and subgroup analyses from RUBY Part 2. The field is now closely watching AstraZeneca’s DUO-E OS data evaluating Imfinzi (durvalumab) + carboplatin/paclitaxel followed by Imfinzi ± Lynparza (olaparib) maintenance. Many KOLs at ESGO positioned these upcoming data as critical for defining the value of additional PARPi maintenance and long-term role of PARPi in the 1L endometrial setting.
- Antibody-drug conjugate (ADC) sequencing in heavily pre-treated ovarian cancer: payload vs target switching
In ovarian cancer, a topic generating strong interest was Eli Lilly’s first-in-human Phase 1 data for sofetabart mipitecan (LY4170156), an FRα-targeting TOP1 inhibitor ADC, presented in ADC-exposed platinum-resistant ovarian cancer (PROC) patients.
Although based on a small cohort (n=27; median 6 prior therapies), the data raised important questions about optimal ADC sequencing strategies.
Notably:
- In 18 patients previously treated with Elahere (mirvetuximab soravtansine), an FRα-targeting tubulin inhibitor ADC, LY4170156 achieved a confirmed ORR of 61.1% with 100% disease control
- In 11 patients previously exposed to other ADCs, including Enhertu, a confirmed ORR of 63.6% was observed
Responses across FRα expression levels raise an important strategic question: Is ADC sequencing driven primarily by switching the payload (the cytotoxic drug delivered by the antibody), switching to alternative targets (such as TROP2 or HER2), or both?
At ESGO, the prevailing clinical sentiment leaned toward payload switching, reflecting concerns around overlapping toxicity and resistance mechanisms linked to payload-driven tumor cell killing. However, the activity observed with LY4170156 also suggests FRα target rechallenge may remain viable under certain conditions.
As ADCs move into earlier lines of therapy, optimizing sequencing and rechallenge strategies will become increasingly important – not only in ovarian cancer but across solid tumors.
At LifeScience Dynamics, we help biopharma partners interpret emerging oncology data and navigate evolving treatment landscapes.
