# Karyopharm Therapeutics

Source: https://onco.cc/companies/karyopharm/  
OnCo record `karyopharm` (Company). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Karyopharm makes selinexor, the first nuclear export inhibitor, approved in myeloma; its endometrial cancer bet failed in 2026.

## Summary

Karyopharm Therapeutics, based in Newton, Massachusetts, and listed as KPTI, makes selinexor, sold as Xpovio, the first nuclear export inhibitor, approved in multiple myeloma and diffuse large B-cell lymphoma. Its bet on endometrial cancer failed in 2026 when the phase 3 XPORT-EC-042 trial of maintenance selinexor in TP53-wild-type disease missed its primary endpoint in July, after which the company refocused on myelofibrosis and myeloma. In September 2026 it missed a loan repayment and entered a forbearance agreement with its lenders and noteholders while it looks for financing or a strategic transaction, and it has said that without one it cannot continue as a going concern; the forbearance period was extended to 1 November 2026. OnCo links it to endometrial cancer, to the XPORT-EC-042 trial record and to selinexor. Whether a biomarker-selected maintenance strategy failed because of the drug or because of the TP53 hypothesis is the question the trial leaves open. Selinexor has its own page.

## Fields

- Kind: Company
- Last checked: 2026-10-29
- HQ: Newton, MA
- Type: biotech
- Website: https://www.karyopharm.com
- Ticker: KPTI

## Notes

- Checked 29 October 2026 against Karyopharm's SEC filings. The 8-K of 11 September 2026 reports a missed principal instalment of about 15.8 million dollars due 10 September 2026 and a forbearance agreement with its lenders, convertible noteholders and royalty investor; the 8-K of 22 October 2026 extends the forbearance period to 1 November 2026. No sale or merger agreement had been filed at the time of checking; the August 2026 results release says the company is evaluating financing opportunities and strategic alternatives.

## Sources

- Official website: https://www.karyopharm.com
- Forbearance agreement and missed loan payment, Form 8-K (SEC): https://www.sec.gov/Archives/edgar/data/1503802/000119312526388621/d94769d8k.htm
- Forbearance extended to 1 November 2026, Form 8-K (SEC): https://www.sec.gov/Archives/edgar/data/1503802/000119312526428938/d172630d8k.htm

## Connected records

- fronts: [Targeted Therapy](https://onco.cc/fronts/targeted-therapy/)
- drugs: [Selinexor](https://onco.cc/drugs/selinexor/)
- trials: [A Study of Rituximab-Gemcitabine-Dexamethasone-Platinum (R-GDP) With or Without Selinexor in Patients With Relapsed/Refractory Diffuse Large B-cell Ly](https://onco.cc/trials/nct04442022/), [A Study of Selinexor (Seli) + Low-dose Dexamethasone (LDD) in Penta-refractory Multiple Myeloma (MM), Seli and Bortezomib + LDD in Triple-class Refrac](https://onco.cc/trials/nct04414475/), [Selinexor (KPT-330) in Patients With Relapsed/Refractory Diffuse Large B-Cell Lymphoma (DLBCL)](https://onco.cc/trials/nct02227251/), [Selinexor and Backbone Treatments of Multiple Myeloma Patients](https://onco.cc/trials/nct02343042/), [Study of Selinexor in Combination With Ruxolitinib in Myelofibrosis](https://onco.cc/trials/nct04562389/), [XPORT-EC-042 / ENGOT-EN20 / GOG-3083](https://onco.cc/trials/xport-ec-042/)
- cancers: [Endometrial cancer](https://onco.cc/cancers/endometrial/)

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