# XPORT-EC-042 / ENGOT-EN20 / GOG-3083

Source: https://onco.cc/trials/xport-ec-042/  
OnCo record `xport-ec-042` (Trial). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

XPORT-EC-042 tested maintenance selinexor against placebo in TP53-normal advanced endometrial cancer after response to platinum chemotherapy, chasing a subgroup finding from the earlier SIENDO trial. It missed its primary endpoint in July 2026: a trend favoured selinexor but did not reach statistical significance, a lesson in the limits of post-hoc biomarker subgroups.

## Summary

The primary PFS endpoint was not met (topline 30 July 2026). A trend favoured selinexor in the modified intent-to-treat population (median PFS 12.75 vs 7.43 months), consistent with the SIENDO exploratory subgroup that motivated the trial, but not statistically significant. Karyopharm cut its endometrial investment. A lesson in the limits of post-hoc biomarker subgroups.

## Fields

- Kind: Trial
- Status: negative
- Last checked: 2026-09-07
- Tags: failure; lesson:subgroup
- Registry id: NCT05611931
- Phase: 3
- Setting: TP53-wild-type advanced or recurrent endometrial cancer after response to platinum: maintenance selinexor vs placebo
- Sponsor: Karyopharm
- Result: Primary PFS endpoint not met; mPFS 12.75 vs 7.43 months (mITT) not significant.
- Outcomes: Progression-free survival (mITT): Selinexor 12.75 months vs Placebo 7.43 months

## Sources

- ClinicalTrials.gov NCT05611931: https://clinicaltrials.gov/study/NCT05611931
- Karyopharm topline: https://investors.karyopharm.com/2026-07-30-Karyopharm-Announces-Topline-Results-from-Phase-3-XPORT-EC-042-Trial-in-Endometrial-Cancer

## Connected records

- cancers: [Advanced or recurrent endometrial cancer](https://onco.cc/cancers/advanced-recurrent-endometrial-cancer/), [Endometrial cancer](https://onco.cc/cancers/endometrial/), [Endometrial cancer with no specific molecular profile](https://onco.cc/cancers/endometrial-nsmp/)
- technologies: [Small-molecule kinase inhibitors](https://onco.cc/technologies/kinase-inhibitors/)
- targets: [TP53](https://onco.cc/targets/tp53/)
- drugs: [Selinexor](https://onco.cc/drugs/selinexor/)
- companies: [Karyopharm Therapeutics](https://onco.cc/companies/karyopharm/)

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