As shown on the FDA official website, 10 drugs each received FDA-approved Orphan Drug Designation for the last 2 consecutive weeks in November, 2019, which can be said to be an "outbreak". Among them, three drugs under development came from Chinese companies, including BeiGene's anticancer drug Tislelizumab, Hutchison MediPharma' anticancer drug surufatinib, and Fosun Pharma's new leukemia drug FN-1501.

On November 20, BeiGene’s Tislelizumab obtained FDA Orphan Drug Qualification for the treatment of hepatocellular carcinoma. In addition, we are concerned that Tislelizumab also obtained FDA Orphan Drug Qualification on November 6 for the treatment of esophageal cancer.

Tislelizumab is a PD-1 inhibitor under development. According to its official introduction, the drug "shows high affinity and specificity for PD-1, and is potentially different from currently approved PD-1 antibodies through Fc fragment modification." It is expected to reduce potential negative interactions with other immune cells.

Tislelizumab has been accepted in China as a new drug application (NDA) for the treatment of patients with relapsed/refractory classic Hodgkin lymphoma (R/R cHL) and has been included in the priority review. In addition to R/R cHL indications, BeiGene is also conducting clinical studies on other indications for Tislelizumab. As a monotherapy, Tislelizumab is currently developing indications worldwide including non-small cell lung cancer, hepatocellular liver cancer, second-line esophageal squamous cell carcinoma, relapsed/refractory Hodgkin lymphoma, urothelial cancer, and relapsed/refractory NK/T cell lymphoma and so on.

In terms of patents, BeiGene filed a patent application titled "Anti-PD1 antibodies and their use as therapeutics and diagnostics" on September 13, 2013 and was granted on November 16, 2018. The patent is CN107090041B, which has more than thirty patent applications in the same patent family that have been granted or are pending in multiple countries and regions.

On November 21, Hutchison MediPharma' surufatinib obtained FDA Orphan Drug Qualification for the treatment of pancreatic neuroendocrine tumors.

Surufatinib is a new anticancer drug with multiple mechanisms of action. It inhibits angiogenesis by inhibiting vascular endothelial growth factor receptor (VEGFR) and fibroblast growth factor receptor (FGFR). In addition, surufatinib can also inhibit colony-stimulating factor-1 receptor (CSF-1R), thereby regulating tumor-associated macrophages and promoting the body's immune response to tumor cells.

It is worth mentioning that this drug is the second innovative tumor drug independently developed by Hutchison MediPharma and successfully completed the Phase 3 clinical trial. Surufatinib's new drug application for the treatment of advanced non-pancreatic NET has been submitted, and was accepted by the China National Drug Administration on November 11, 2019. Once entry market through Orphan Drug Designation by the FDA, surufatinib will have a 7-year market exclusivity for this indication, and it will also bring some development cost benefits in the United States.

At the same time, because the drug has dual mechanisms of anti-tumor angiogenesis and immune regulation, it may be very suitable for use in combination with other immunotherapy. Currently, surufatinib is being studied in China and the United States as a monotherapy or in combination with other tumor immunotherapy for a variety of solid tumors.

In terms of patents, Hutchison MediPharma filed a patent application titled "Compound and crystals thereof" on November 23, 2009 and was granted on August 21, 2013. The patent is CN102070618B, which has more than thirty patent applications in the same patent family that have been granted or are pending in multiple countries and regions. The company has all the rights of surufatinib worldwide.

On November 26, Fosun Pharma's FN-1501 obtained FDA Orphan Drug Qualification for the treatment of acute myeloid leukemia.

FN-1501 is an inhibitor capable of targeting multiple tyrosine kinases, the generic name of which is 4-((7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)-N-(4-((4- methylpiperazin-1-yl)methyl)phenyl)-1H-pyrazole-3-carboxamide, (2Z)-2-butenedioate (1:2), Sesquihydrate. A study in the Journal of Clinical Oncology showed that it can target CDK4/6, PDGFR, KIT, ALK, RET and FLT3 proteins.

FN-1501 is an innovative small-molecule chemical drug that Fosun Pharma transferred from China Pharmaceutical University and developed independently. The new drug has been approved by the US FDA, the China Food and Drug Administration (now the National Medical Products Administration) in clinical trials in October 2017 and December 2017, respectively. The drug under development for the treatment of leukemia and solid tumors is currently in phase 1 clinical trials in the United States, Australia, and mainland China.

In terms of patents, Fosun Pharma filed a patent application titled "Polycyclic substituted pyrazole kinase activity inhibitors and use thereof" on January 7, 2014 and was granted on July 18, 2017. The patent is CN105189517B, with up to twenty granted or pending family patent applications in multiple countries and regions.

Orphan Drug is a type of pharmaceutical products that treat rare diseases. Rare diseases refer to the varities of diseases that have a very low incidence in the entire population. Although the incidence of single rare disease is not high, according to the World Health Organization (WHO), there are 5000 to 8000 rare diseases in the world, which means that the total number of patients with all types of rare diseases adds up to nearly 400 million. In other words, there is one rare disease patient in less than 20 people.

As the research and development of drugs for rare diseases are facing challenges such as the small number of patients and difficulties in understanding the mechanisms of the diseases, governments and regulatory agencies around the world have provided preferential policies for the research and development of orphan drugs for rare diseases. Innovative orphan drugs can not only have a longer period of market exclusivity, but also receive assistance to varying degrees of resources in the research and development process. This area is being valued by many pharmaceutical companies and has become one of the fastest growing areas of drug development in the past few years.

The products of the above three Chinese companies have obtained the Orphan Drug Designation granted by the US FDA. With the help of special qualifications, they will definitely bring hope for treatment to these patients at an early date. This is also the pride of Chinese pharmaceutical companies.