Antengene Announces NDA for ATG-010 (Selinexor) Granted Priority Review by China's NMPA

Antengene Corporation Limited, a leading innovative biopharmaceutical company dedicated to discovering, developing and commercializing global first-in-class and/or best-in class therapeutics in hematology and oncology, today announced that China's National Medical Products Administration (NMPA) has granted priority review to the New Drug Application (NDA) for ATG-010 (selinexor, XPOVIO®), a first-in-class selective inhibitor of nuclear export (SINE) compound, for the treatment of patients with relapsed/refractory multiple myeloma (rrMM).

ATG-010 is the first approved SINE compound in the world. It induces the apoptosis of cancer cells in vitro and in vivo by causing the nuclear storage and activation of tumor suppressor proteins and other growth-regulating proteins, and by down-regulating the intracytoplasmic levels of various oncogenic proteins while normal cells are not affected. The US Food and Drug Administration (FDA) has approved ATG-010 (selinexor) as a novel treatment in three indications within eighteen months. Five ATG-010 regimens for patients with multiple myeloma or diffuse large B-cell lymphoma have also been added to the National Comprehensive Cancer Network (NCCN®) Guidelines. Antengene has completed patient enrollment for the registrational clinical trial in rrMM in mainland China and has submitted NDAs for ATG-010 in five APAC markets including Australia, South Korea and Singapore over the past six months.

"ATG-010 is a novel option for the treatment of rrMM and we are pleased that it has been granted priority review by the NMPA. The target of ATG-010, XPO1, is the only proven nuclear export protein target in clinical development and we believe that ATG-010 has potential to meet the huge unmet medical needs in hematological malignancies and solid tumors." said Dr. Jay Mei, M.D., PhD., Founder, Chairman and CEO of Antengene. "rrMM still remains an incurable disease and we are excited that more patients may have access to ATG-010 earlier in the course of their treatment. We look forward to working closely with the regulatory authority to move this important indication for ATG-010 towards approval."

"Working Procedures for Priority Review and Approval of Drug Marketing Authorization (Interim)" has been issued by the NMPA on July 7, 2020 to expedite the development and registration of drugs that provide significant clinical value. With the effective implementation of these procedures, the regulatory authority will expedite the evaluation and approval of novel drugs through a priority review pathway and facilitate earlier access of these drugs to patients in China.

About ATG-010 (selinexor, XPOVIO®)

ATG-010 (selinexor, XPOVIO®), a first-in-class and only-in-class oral selective inhibitor of nuclear export (SINE) compound discovered and developed by Karyopharm Therapeutics Inc. (NASDAQ: KPTI), is currently being developed by Antengene, which has the exclusive development and commercial rights in certain Asia-Pacific markets, including Greater China, South Korea, Australia, New Zealand and the ASEAN countries.

In July 2019, the US Food and Drug Administration (FDA) approved selinexor (XPOVIO®) in combination with low-dose dexamethasone for the treatment of relapsed/refractory multiple myeloma (rrMM) and in June 2020 approved selinexor (XPOVIO®) as a single-agent for the treatment of relapsed/refractory diffuse large B-cell lymphoma (rrDLBCL). In December 2020, selinexor (XPOVIO®) also received FDA approval as a combination treatment for multiple myeloma after at least one prior therapy. A Marketing Authorization Application (MAA) has also been submitted to the European Medicines Agency (EMA) with a request for conditional approval of selinexor in this same rrMM indication. Selinexor (XPOVIO®) is so far the first and only oral SINE compound approved by the FDA and is the first drug approved for the treatment of both MM and DLBCL. Selinexor (XPOVIO®) is also being evaluated in several other mid-and later-phase clinical trials across multiple solid tumor indications, including liposarcoma and endometrial cancer. In November 2020, at the Connective Tissue Oncology Society 2020 Annual Meeting (CTOS 2020), Antengene's partner, Karyopharm, presented positive results from the Phase 3 randomized, double blind, placebo controlled, cross-over SEAL trial evaluating single agent, oral selinexor (XPOVIO®) versus matching placebo in patients with liposarcoma. Karyopharm also announced that the ongoing Phase 3 SIENDO trial of selinexor (XPOVIO®) in patients with endometrial cancer passed the planned interim futility analysis and the Data and Safety Monitoring Board (DSMB) recommended the trial should proceed as planned without any modifications. Top-line SIENDO trial results are expected in the second half of 2021.

About Antengene

Antengene Corporation Limited ("Antengene", SEHK: 6996.HK) is a leading clinical-stage Asia-Pacific biopharmaceutical company focused on innovative oncology medicines. Antengene aims to provide the most advanced anti-cancer drugs to patients in China, the Asia Pacific Region and around the world. Since its establishment, Antengene has built a pipeline of 12 clinical and pre-clinical stage assets and obtained 12 investigational new drug approvals in Asia Pacific. The vision of Antengene is to "Treat Patients Beyond Borders". Antengene aims to address significant unmet medical needs by discovering, developing and commercializing first-in-class/best-in-class therapeutics.