21st Century Business Herald reporter Lei Ruoxin reported from Shenzhen

On the third trading day after the New Year, Chipscreen Biosciences (688321. SH) issued three announcements in a row, all of which were about its core product, chidamide.

According to the announcement, on January 23, Nanjing Chia Tai Tianqing Pharmaceutical Co., Ltd. (hereinafter referred to as "Chia Tai Tianqing") filed a request for invalidation of the invention patent of chidamide "a TRKA (G667C) and FLT3 target inhibitor and its composition with chidamide" (patent number: ZL202211051615.8), and Chipscreen Biosciences received the "Notice of Acceptance of Invalidation Request" on February 5.

On December 30, Chia Tai Tianqing also filed a request for invalidation of another patent of chidamide, "an E-configuration benzamide compound and its medicinal preparation and application" (patent number: ZL201410136761.X), and Chipscreen Biosciences announced on January 16 that it had received a notice of acceptance.

Two patent invalidation requests, successively targeting the ace product developed by Microchip Biosciences for 13 years - chidamide.

According to the data, chidamide (Apsisa) is a national class 1 original innovative drug, the first original anti-tumor drug developed by Chipscreen Biosciences, and the first orally selective histone deacetylase (HDAC) inhibitor in this field. At present, chidamide has been approved for 3 and 1 indications in China and Taiwan, respectively, and 2 indications have been approved in Japan. In addition, chidamide is the only oral innovative drug approved for the first-line treatment of DLBCL in China and reimbursed by medical insurance. In November last year, the new indication of chidamide tablets, diffuse large B-cell lymphoma, was included in the "National Medical Insurance Catalog" for the first time.

Currently, chidamide is a well-deserved revenue pillar for Chipscreen Biosciences. According to its 2023 annual report, chidamide achieved operating income of 467 million yuan, with a gross profit margin of 96.09%, accounting for nearly 90% of total revenue.

Chipscreen Biosciences mentioned in its 2024 performance forecast that the sales volume of chidamide and siglitamida sodium increased significantly, which led to the growth of the company's revenue. According to media reports, Chipscreen Biosciences disclosed at the offline exchange meeting in late August 2024 that as of the date of the exchange meeting, the cumulative sales revenue of chidamide exceeded 2.3 billion yuan, and the cumulative license benefited nearly 200 million yuan.

In the field of biomedicine, patent confrontations between original drugs and generic drugs are endless. As a biotechnology company focusing on the research and development of original innovative drugs, this is not the first time that Chipscreen Biosciences has faced patent challenges.

On the eve of the listing of chidamide, Dr. Hunter Laboratories Co., Ltd. filed a patent invalidation request for its core patent "benzamide histone deacetylase inhibitors with differentiation and anti-proliferative activity and their pharmaceutical preparations", and successfully maintained the validity of the patent after examination. Chipscreen Biosciences' other product, siglitat sodium, was also challenged by patent invalidation, but was successfully maintained as effective.

However, the Chia Tai Tianqing faced by Chipscreen Biosciences this time can be described as fruitful in the field of drug patent challenges, and the record can be checked.

In 2011, Bristol-Myers Squibb initiated a patent infringement lawsuit, pointing to the first imitation entecavir tablets launched by Zhengda Tianqing. After nine years of "marathon" lawsuits, Bristol-Myers Squibb's patent infringement lawsuit was dismissed, and the patents in question were found to be invalid. The launch of CT Tianqing's entecavir tablets has removed patent barriers.

In 2021, CT Tianqing will compete with Novartis Pharmaceuticals of Switzerland, whose original everolimus once ranked among the "blockbuster" echelons with annual sales of more than $2 billion. CT Tianqing has successively submitted invalidation requests for three related patents involved in everolimus tablets, and it will be granted in 2022. At the beginning of 2024, CT Tianqing not only received the everolimus registration certificate and won the first generic drug in China, but also became a product with a 12-month market exclusivity period of "first generic approval + successful first challenge patent" since the implementation of China's early resolution mechanism for drug patent disputes (drug patent linkage system).

In August 2024, CT Tianqing successfully invalidated two patents of Degarek, the "star drug" of Danish Ferring Pharmaceutical, and is currently competing for the position of its first generic drug. In addition, among the new generic drugs under review by Chia Tai Tianqing, there are many products that have not been approved for the first generic in China.

In the face of "professional thugs", Chipscreen Biosciences said that it has laid out a number of invention patents around chidamide-related technologies and applications, and the maximum patent protection period has been extended to 2042. Even if the patent involved in this case is ultimately found to be invalid, chidamide products are still protected by other patents and will not have a material adverse impact on the company's production and operation.

In addition, Chipscreen Biosciences also disclosed that chidamide has obtained the approval notice for drug clinical trials, and will conduct a randomized, double-blind, placebo-controlled, multicenter, phase III clinical trial of chidamide in combination with CHOP for the treatment of treatment-naïve, peripheral T-cell lymphoma with follicular helper T-cell phenotype (PTCL-TFH).