Press Release

Jul 20, 2018

Antengene Corporation’s Strategic Partner, Karyopharm Therapeutics, Initiates Rolling Submission of New Drug Application to U.S. Food and Drug Administration for Selinexor as a Treatment for Patients with Penta-Refractory Multiple Myeloma

Shanghai, China and NEWTON, Mass. – July 18, 2018 – Antengene Corporation’s Strategic Partner, Karyopharm Therapeutics Inc. (Nasdaq:KPTI), a clinical-stage pharmaceutical company, today announced that the Company has initiated a rolling submission of a New Drug Application (NDA) to the U.S. Food and Drug Administration (FDA) seeking accelerated approval for selinexor, its novel, oral SINE compound, as a new treatment for patients with penta-refractory multiple myeloma. Patients with penta-refractory myeloma have previously received two proteasome inhibitors (PIs), Velcade® (bortezomib) and Kyprolis® (carfilzomib), and two immunomodulatory drugs (IMiDs), Revlimid® (lenalidomide) and Pomalyst® (pomalidomide), and their disease is refractory to at least one PI, at least one IMiD, and their disease is also refractory to the anti-CD38 monoclonal antibody Darzalex® (daratumumab), and has progressed following their most recent therapy. The Company expects to complete the NDA submission during the second half of 2018. Selinexor has received both Orphan Drug and Fast Track designations from the FDA.

Pending marketing approval by the FDA, Karyopharm plans to commercialize selinexor in the U.S. The Company also plans to submit a Marketing Authorization Application to the European Medicines Agency with a request for conditional approval in early 2019.

In May 2018, Antengene and Karyopharm entered into a broad strategic partnership in Shanghai

In May 2018, Antengene and Karyopharm Therapeutics entered into a broad strategic partnership with Karyopharm and obtained exclusive rights for development and commercialization four of Karyopharm’s clinical-stage, novel, oral drug candidates, including selinexor, in various Asian countries and regions. In consideration of differences in treatment landscape between China and the U.S., Antengene plans to first pursue an indication of selinexor in treatment of relapsed/refractory multiple myeloma patients whose disease progressed after treatment with chemotherapy, proteasome inhibitors (PIs) and immunomodulatory drugs (IMiDs). Antengene Corporation has communicated clinical development and filing plans in relapsed/refractory multiple myeloma and following indications with health authority in China, and will submit application in 3Q 2018.

Strategic Partnership Launching Ceremony

About Antengene Corporation

Antengene Corporation is a clinical-stage biopharmaceutical company focused on developing and commercializing innovative therapeutics to meet unmet medical needs in Asia. Antengene aims to provide the most advanced and first-in-class anti-cancer drug treatments for patients in China and rest of Asia. On April 13, 2017, Celgene Corporation (Nasdaq: CELG), a global leading innovative biopharmaceutical company became a long-term strategic partner and obtained an equity position in Antengene. Antengene’s pipeline includes five clinical stage products, from Phase 2/3 and NDA stage ATG-010 for relapsed/refractory multiple myeloma, lymphomas and solid tumors, to ATG-008 that is in multi-regional clinical trial currently enrolling late stage HCC patients in Taiwan, South Korea and mainland China. Two other Phase 1 and Phase 2 clinical stage drugs, ATG-016 and ATG-019, are being studied in multiple cancer types, including MDS, colorectal and prostate cancers. ATG-527, studied in a completed Phase 1 trial, is being explored for multiple anti-viral indications, including influenza, respiratory syncytial virus (RSV), epstein-barr virus (EBV) related diseases.

About Selinexor (ATG-010)

Selinexor (ATG-010) is a first-in-class, oral Selective Inhibitor of Nuclear Export / SINE compound. Selinexor functions by binding with and inhibiting the nuclear export protein XPO1 (also called CRM1), leading to the accumulation of tumor suppressor proteins in the cell nucleus. This reinitiates and amplifies their tumor suppressor function and is believed to lead to the selective induction of apoptosis in cancer cells, while largely sparing normal cells. To date, over 2,500 patients have been treated with selinexor. In April 2018, Karyopharm reported positive top-line data from the Phase 2b STORM study evaluating selinexor in combination with low-dose dexamethasone in patients with penta-refractory multiple myeloma. Selinexor has been granted Orphan Drug Designation in multiple myeloma and Fast Track designation for the patient population evaluated in the STORM study. Karyopharm has initiated a rolling submission for a New Drug Application (NDA) to the U.S. Food and Drug Administration (FDA), with a request for accelerated approval for oral selinexor as a new treatment for patients with penta-refractory multiple myeloma and expects the submission to be complete during the second half of 2018. The Company also plans to submit a Marketing Authorization Application (MAA) to the European Medicines Agency (EMA) in early 2019 with a request for conditional approval. Selinexor is also being evaluated in several other mid- and later-phase clinical trials across multiple cancer indications, including in multiple myeloma in a pivotal, randomized Phase 3 study in combination with Velcade® (bortezomib) and low-dose dexamethasone (BOSTON) and as a potential backbone therapy in combination with approved therapies (STOMP), and in diffuse large B-cell lymphoma (SADAL), liposarcoma (SEAL), and an investigator- sponsored study in endometrial cancer (SIENDO), among others. Additional Phase 1, Phase 2 and Phase 3 studies are ongoing or currently planned, including multiple studies in combination with one or more approved therapies in a variety of tumor types to further inform Karyopharm's clinical development priorities for selinexor. Additional clinical trial information for selinexor is available at www.clinicaltrials.gov.

About Karyopharm Therapeutics

Karyopharm Therapeutics Inc. (Nasdaq: KPTI) is a clinical-stage pharmaceutical company focused on the discovery and development of novel first-in-class drugs directed against nuclear transport and related targets for the treatment of cancer and other major diseases. Karyopharm's SINE compounds function by binding with and inhibiting the nuclear export protein XPO1 (or CRM1). In addition to single-agent and combination activity against a variety of human cancers, SINE compounds have also shown biological activity in models of neurodegeneration, inflammation, autoimmune disease, certain viruses and wound- healing. Karyopharm, which was founded by Dr. Sharon Shacham, currently has several investigational programs in clinical or preclinical development. For more information, please visit www.karyopharm.com.

Contacts:

Investors:
Jeff Li
(+86) 186-2162-5820
jeff.li@antengene.com

Media:
Peter Qian
(+86) 134-5670-2902
peter.qian@antengene.com