Karyopharm Reports Results of Phase 3 Trial on Endometrial Cancer Treatment

Karyopharm's Phase 3 XPORT-EC-042 Trial Results on Selinexor

Karyopharm Therapeutics Inc., a leading developer in innovative cancer therapies, recently disclosed topline data from its Phase 3 clinical trial, XPORT-EC-042, focusing on a significant segment of endometrial cancer patients. This trial assessed the efficacy of selinexor, a novel oral exportin 1 (XPO1) inhibitor, compared to placebo as a maintenance therapy in adult patients diagnosed with advanced or recurrent endometrial cancer exhibiting wild-type TP53.

Despite the trial not accomplishing its primary goal of demonstrating statistically significant improvement in progression-free survival (PFS), notable trends were observed. In the modified Intent-to-treat (mITT) population—comprising 236 participants—it was recorded that patients receiving selinexor exhibited a median PFS of 12.75 months, surpassing the 7.43 months reported for the placebo group, with a hazard ratio of 0.76 (95% CI [0.51, 1.12]). Although this outcome did not reach statistical significance (one-sided p-value = 0.0791), it signifies a 5.3-month enhancement in median PFS for the selinexor arm.

The trial’s safety profile of selinexor proved consistent with previously established data, revealing no new safety signals. According to Karyopharm’s CMO, Dr. Reshma Rangwala, these findings serve to advance understanding of XPO1 inhibition, providing potential benefits for thousands grappling with this challenging condition.

Insights from Medical Experts

Eminent oncologists involved in the trial voiced their perspectives on the findings. Professor Ignace Vergote, a gynecologic oncologist from the Catholic University of Leuven, emphasized the importance of the preliminary findings for patients lacking efficient maintenance therapies capable of hindering disease progression. “A five-month delay in cancer progression is noteworthy and encouraging,” adds Dr. Robert Coleman from Texas Oncology.

Despite the results falling short of expectations, Karyopharm’s leadership maintains confidence in the broader potential of selinexor. President and CEO Richard Paulson remarked, “We remain committed to exploring selinexor’s applications beyond endometrial cancer, directing resources towards our promising myelofibrosis and multiple myeloma programs.”

Future Directions

Karyopharm intends to conduct a comprehensive analysis of the XPORT-EC-042 trial data and aims to present these findings at forthcoming medical assemblies. This study's outcome does not alter ongoing selinexor trials for various other conditions, reinforcing the company’s commitment to develop targeted therapies for patients with significant unmet needs.

About Endometrial Cancer

Endometrial cancer remains a substantial health concern, being the most common gynecologic malignancy in the U.S. Ongoing trends indicate rising incidence and mortality rates, with estimates forecasting that approximately 68,000 new cases of uterine cancer will emerge in 2026, leading to about 14,000 fatalities. Given its complex relationship with factors such as obesity and diabetes, further research into targeted therapies for patients with TP53 wild-type tumors is urgently required.

Karyopharm’s tireless efforts in advancing scientific knowledge surrounding endometrial cancer treatment and XPO1 inhibition echo a broader commitment to innovate and respond to the critical requisites of cancer patients worldwide.