Karyopharm Therapeutics Inc.: forbearance period extended to Oct 22, 2026

What happened The filing reports that Karyopharm Therapeutics Inc. had previously entered into a Forbearance Agreement and Limited Waiver to Indentures dated Sep 10, 2026 and disclosed in a Form 8-K filed Sep 11, 2026. On Oct 13, 2026, in accordance with Section 19 of the Forbearance Agreement, the applicable parties extended the date on which the Forbearance Period will end, absent earlier termination, from 11:59 p.m., Eastern time, on Oct 15, 2026 to 11:59 p.m., Eastern time, on Oct 22, 2026.

Key details

• Forbearance Agreement and Limited Waiver to Indentures dated Sep 10, 2026 (previously disclosed in the Form 8-K filed Sep 11, 2026).
• Extension action taken on Oct 13, 2026 under Section 19 of the Forbearance Agreement.
• Forbearance Period end date changed from 11:59 p.m., Eastern time, on Oct 15, 2026 to 11:59 p.m., Eastern time, on Oct 22, 2026.
• Extension is described as effective "absent earlier termination."

Why it may matter This report is filed under Item 8.01 (other events), which covers events the company considers material to investors; here the reported event is an extension of the Forbearance Period under the Forbearance Agreement. The filing does not show why the company acted.