July 5, 2019

Karyopharm Announces FDA Approval of XPOVIOTM (selinexor) for the Treatment of Patients with Relapsed or Refractory

This information is intended to notify the press release issued on July 3 (ET) by Karyopharm Therapeutics Inc. Please click http://investors.karyopharm.com/press-releases for the original press release distributed by Karyopharm.

1st paragraph of the press release: (NEWTON, Mass., July 3, 2019) -- Karyopharm Therapeutics Inc. (Nasdaq: KPTI), an oncology- focused pharmaceutical company, today announced that the U.S. Food and Drug Administration (FDA) has approved oral XPOVIOTM (selinexor), a nuclear export inhibitor, in combination with for the treatment of adult patients with relapsed or refractory multiple myeloma (RRMM) who have received at least four prior therapies and whose disease is refractory to at least two proteasome inhibitors, at least two immunomodulatory agents, and an anti-CD38 . This indication is approved under accelerated approval based on response rate. Continued approval for this indication may be contingent upon verification and description of clinical benefit in a confirmatory trial. The ongoing, randomized Phase 3 BOSTON study evaluating selinexor in combination with Velcade® () and low-dose dexamethasone will serve as the confirmatory trial. The FDA’s Accelerated Approval Program was developed to allow for expedited approval of drugs that treat serious conditions and that fill an unmet medical need.

About the Ono and Karyopharm Collaboration In October 2017, Ono Pharmaceutical Co., Ltd. concluded an exclusive license agreement with Karyopharm Therapeutics Inc. for the development and commercialization of Selinexor, their first-in- class oral XPO1 (Exportin 1) inhibitor, and Eltanexor/KPT-8602, a second-generation oral XPO1 inhibitor, for all oncology indications exclusively in Japan, South Korea, Taiwan, Hong Kong and ASEAN countries.

About the Development Status of Selinexor (ONO-7705) in Japan Selinexor (ONO-7705) is now under Phase I study in Japan for the treatment of multiple myeloma and non-Hodgkin .

Contacts: ONO PHARMACEUTICAL CO., LTD. Corporate Communications [email protected]