Domestic original anti-cancer drugs encounter patent challenges.

On January 16, Microchip Biotechnology (688321.SH) issued an announcement stating that on December 30, 2024, Nanjing Zhengda Tianqing Pharmaceutical Co., Ltd. (hereinafter referred to as "Zhengda Tianqing") filed a request for invalidation of the company's cedabendamine product patent with the State Intellectual Property Office. After formal review, the State Intellectual Property Office issued a "Notice of Acceptance of Invalidation Request" on January 13, 2025.
According to the announcement, the patent involved in the case is an invention patent for "an E-configuration benzamide compound and its pharmaceutical preparation and application" (patent number: ZL201410136761.X).

This patent is one of the series of patents that ChipScreen Biotech has laid out for its product line of ChipScreen Biotech, which was applied for by ChipScreen Biotech to the State Intellectual Property Office on April 4, 2014, and was authorized on May 17, 2017. The patent is valid until April 4, 2034.

Regarding this patent challenge, Lu Xianping, founder and chairman of ChipScreen Biotech, responded to Times Finance, saying, "This is a normal situation in the industry. The company has announced the specific situation and is actively preparing to respond. The patent protection period is time-limited and will come sooner or later. But companies will also form a variety of multi-level protection strategies to extend the protection period as much as possible."

Star drug challenged for patent invalidation
The official website and annual report show that ChipScreen Biotech (trade name: Aipusha) is a new molecular entity drug exclusively discovered by ChipScreen Biotech, with a novel mechanism. It is the world's first subtype-selective histone deacetylase (HDAC) inhibitor and the world's first oral treatment drug approved for the treatment of peripheral T-cell lymphoma and advanced hormone-positive breast cancer. It belongs to the class of epigenetic regulators. In 2015, Chidamide became China's first original new drug authorized for patent use in developed countries such as the United States.

As the flagship product of Microchip Bio, Chidamide was challenged for invalid patents this time, which inevitably attracted market attention.
"Patent applications in the biopharmaceutical industry are usually precedent. A new product or technology, from theoretical research to practical application, including promotion, takes time. After ten years of development, the technology and market are mature. If peers or competitors also hope to produce similar drugs, most of them will first consider filing a patent invalidation, which is very normal. In China, the cost of filing a patent invalidation is not worth mentioning compared to the license fee paid." Zhang Wenbo, senior partner of Beijing Jundu Shanghai Law Firm and director of the Life Science and Health Medical Law Department, told Times Finance.

Zhang Wenbo pointed out to Times Finance based on the information he learned from the official website of the patent right, "The patent involved in the case of Chipscreen Biopharma's Chidamide was rejected by the State Intellectual Property Office and then approved after the review procedure. When the original application was made, the rights claimed included compounds and uses. It should be that the compounds were disclosed by the existing technology, so the patent for use was finally authorized."

In this regard, Times Finance contacted Chipscreen Biopharma for verification, and the relevant person from the Securities Department explained that "the patent involved in the case is the indication patent of Chidamide, which is only one of the patent systems of Chidamide. Patent challenges are issues that most original research pharmaceutical companies at home and abroad will encounter. The company has laid out a number of invention patents around the crystal form, key impurities, preparations and indications of Chidamide. We believe that invalidation applications for individual patents cannot break through the company's patent system around Chidamide.".

Regarding the subsequent impact of this incident, Microchip Bio mentioned in the announcement, "In view of the fact that the State Intellectual Property Office has only accepted the applicant's request for invalidation of the patent, and has not yet formally reviewed it, let alone made a final decision on this invalidation request. There is no final result for this matter, and the patent involved in this case is only one of the patent systems deployed by the company. Therefore, this invalidation request has no significant adverse impact on the company's current or post-period profits. "

However, Zhang Wenbo pointed out to Times Finance that whether it is for the challenging party or the challenged party, the process of patent challenge requires a lot of manpower, material resources and other costs. This is not the first time that Chidamide has encountered a patent invalidation challenge. Public information shows that in November 2013, Dr. Hunter Laboratories, Inc. of the United States filed a patent invalidation request with the Patent Reexamination Board for the patent of "Benzamide histone deacetylase inhibitors with differentiation and anti-proliferation activity and their pharmaceutical preparations" owned by Microchip Bio (patent number: ZL03139760.3, the patent involved is the core patent of "Cidamide"), and the final result is that it remains valid.

In addition to Sidabendine, ChipScan's Sitagliptin has also received patent invalidation challenges. This is a new generation of insulin sensitizers designed, synthesized, screened and developed by ChipScan. It is the world's first PPAR full agonist for insulin resistance and my country's first original diabetes drug. It was approved for marketing by the National Medical Products Administration on October 19, 2021 for the treatment of type 2 diabetes.

On April 22, 2021, the invalidation applicant Yu Xiaodong filed a partial invalidation request with the State Intellectual Property Office for the compound patent of Sitagliptin. The result this time is that the State Intellectual Property Office declared on January 4, 2022 that the core claims 2-4, 6-9 and 15-18 involving the compound and preparation method of Sitagliptin remained valid.

Chidabendine has accumulated sales of more than 2.3 billion yuan
According to the official website, ChipScan was established in 2001 and focuses on the research and development of original drugs in five major fields: malignant tumors, metabolic diseases, autoimmune diseases, central nervous system diseases and antiviral drugs. In August 2019, Chipscreen Biopharma was listed on the Science and Technology Innovation Board, becoming the first company to pass the review and the first listed biopharmaceutical company on the Science and Technology Innovation Board.

As of the announcement disclosed on November 28, 2024, Chidamide has been approved for three indications in China: peripheral T-cell lymphoma, breast cancer, and diffuse large B-cell lymphoma, and has been approved for breast cancer indications in Taiwan, China.

In terms of overseas markets, Chidamide has been approved for two indications in Japan: adult leukemia and peripheral T-cell lymphoma.
According to the financial report data, in 2023, Chidamide recorded revenue of 467 million yuan and a gross profit margin of 96.09%. Times Finance learned from the offline exchange meeting held by Chipscreen Biopharma in mid-to-late August 2024 that as of this exchange meeting, Chidamide's cumulative sales revenue exceeded 2.3 billion yuan and the cumulative licensing income was nearly 200 million yuan.

Microchip Bio has high hopes for this flagship product. Currently, Chidamide is promoting multiple clinical trials in China and internationally in combination with different anti-tumor immunotherapies, including the clinical study of Chidamide combined with Sintilimab and Bevacizumab for the treatment of colorectal cancer, and the clinical study of combined Tislelizumab as the first-line treatment for non-small cell lung cancer. As of the disclosure of the semi-annual report in 2024, these two clinical studies have progressed to clinical phase III and clinical phase II respectively.

In the announcement, Chipscreen Biopharma emphasized that "the company has formed a patent protection system for products related to Chidamide, which is jointly constructed by multiple patents such as compounds, crystal forms, key impurities, preparations, and indications. The longest patent protection period has been extended to August 30, 2042. The patent involved in the case is one of the patents for indications in the patent protection system of Chidamide. The application for invalidation of individual patents cannot break through the company's patent system around Chidamide. Therefore, even if the patent involved in this case is ultimately deemed invalid, Chidamide products are still protected by other patents, which will not affect the company's continued production, sales, and use of Chidamide products, and will not have a significant adverse impact on the company's production and operation."

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