[HONG KONG, China, Dec. 8, 2022] SciClone Pharmaceuticals (Holdings) Limited (“SciClone Pharmaceuticals”, HKEX: 6600) announced today that the China National Medical Products Administration (the “NMPA”) has approved DANYELZA^® (naxitamab-gqgk), referred to as DANYELZA^®, for the treatment, in combination with granulocyte macrophage colony-stimulating factor (“GM-CSF”), of pediatric patients 1 year of age and older and adult patients with relapsed or refractory high-risk neuroblastoma in the bone or bone marrow who have demonstrated a partial response, minor response, or stable disease to prior therapy (the “Indication”).

In Greater China (including Mainland China, Hong Kong, Macau and Taiwan), DANYELZA^® is expected to be developed and commercialized by SciClone Pharmaceuticals, under the exclusive license agreement entered into in 2020 between SciClone Pharmaceuticals and Y-mAbs Therapeutics, Inc. DANYELZA^® received Priority Review, Breakthrough Therapy, Orphan Drug and Rare Pediatric Disease designations from the Food and Drug Administration (the “FDA”) in the United States (“U.S.”). In November 2020, DANYELZA^® was approved for the Indication by the FDA under accelerated approval regulation based on overall response rate (ORR) and duration of response (DoR). In September 2021, the NMPA granted priority review to the Biologics License Application (“BLA”) for DANYELZA^®, under the relevant policies and regulations of China that encourage research and development of innovative new drugs with apparent clinical benefits and urgent clinical needs.

Prior to the BLA approval by the NMPA, benefitting from policy support in China, SciClone Pharmaceuticals pilot launched DANYELZA^® in the Hainan Bo’Ao Lecheng International Medical Tourism Pilot Zone and the China (Tianjin) Pilot Free Trade Zone in June 2021 and December 2021, respectively. In September 2021, SciClone Pharmaceuticals submitted a marketing application for DANYELZA^® in Macau. In January 2022, SciClone Pharmaceuticals started selling DANYELZA^® in Taiwan based on local special import policy.

About Neuroblastoma (“NB”)

Neuroblastoma is the most common extracranial solid tumor of childhood, accounting for 8%~10% of malignant tumor of childhood. According to the International Neuroblastoma Risk Group (INRG) staging system, patients are categorized into extremely low-risk, low-risk, medium-risk and high-risk groups at time of diagnosis, of which high-risk patients account for more than 50%. Even after multimodal therapy such as chemotherapy, surgery, radiotherapy and transplantation, the prognosis of patients with high-risk NB remains poor, and the long-term survival rate is less than 50%.

The overall prognosis of NB reported in China seems to be worse than that observed abroad. Most patients have extensive metastases at the time of diagnosis and are categorized as high-risk NB, which is the key issue that leads to increased difficulty in treatment, easy recurrence and poor prognosis. A study of 1,041 patients with NB in China published by Beijing Children’s Hospital in 2020 suggests that there is an urgent need for new treatments in China to improve the prognosis of high-risk NB patients, as the 5-year survival rate of these patients was significantly reduced.

Naxitamab is currently the only approved humanized, monoclonal antibody targeting GD2 in the world. Through binding to GD2 on the NB cell surface, it triggers antibody-dependent cell-mediated cytotoxicity (ADCC) and complement dependent cytotoxicity (CDC), leading to tumor killing.

In November 2020, the FDA approved DANYELZA^® for the treatment, in combination with GM-CSF of pediatric patients 1 year of age and older and adult patients with relapsed or refractory high-risk neuroblastoma in the bone or bone marrow who have demonstrated a partial response, minor response, or stable disease to prior therapy. This indication was approved under accelerated approval regulation based on overall response rate (ORR) and duration of response (DoR). Continued approval for this indication may be contingent upon verification and description of clinical benefits in a confirmatory trial.

In Study 201 sponsored by Y-mAbs, treatment with naxitamab was associated with an overall manageable safety profile. In terms of immunogenicity, 8% of patients tested positive for anti-drug antibodies. A naxitamab infusion typically lasts 30-60 minutes, which makes it possible to administer naxitamab in the outpatient setting without the need for overnight stay. This has the potential to reduce the burden for patients and families.

In December 2020, SciClone Pharmaceuticals entered into a license agreement with Y-mAbs and obtained the rights to exclusively co-develop and commercialize naxitamab in Greater China (including Mainland China, Hong Kong, Macau and Taiwan).

In July 2021, approximately seven months after DANYELZA^® was approved by the FDA, SciClone Pharmaceuticals submitted a BLA for naxitamab to the NMPA. In September 2021, the NMPA granted the BLA for naxitamab priority review, and SciClone Pharmaceuticals submitted the marketing application for naxitamab in Macau in the same month.

Benefiting from policy support in China, SciClone Pharmaceuticals pilot launched DANYELZA^® in the Hainan Bo’Ao Lecheng International Medical Tourism Pilot Zone and the China (Tianjin) Pilot Free Trade Zone in June 2021 and December 2021, respectively.

Since January 2022, SciClone Pharmaceuticals started selling DANYELZA^® in Taiwan based on local special import policy.