The starting point of patent wars often lies at the source of innovation: drug targets and molecules.

At this starting point that determines the lifeline of drug R&D, Chinese biotech companies are collectively facing a test concerning the legitimacy of innovation and business ethics, with the core being how to define the "origins" of an innovation. The prolonged dispute between MediGene Biotech and 3Sbio over the interleukin-4 receptor alpha (IL-4Rα) target is a perfect case in point.

IL-4Rα is a golden target for the treatment of diseases such as asthma and atopic dermatitis. Its huge market prospects have attracted numerous enterprises to deploy relevant R&D efforts, making the scramble for priority rights over it particularly fierce.

The core thread of this dispute began with the mobility of key R&D personnel. The core team members of MediGene Biotech, including founder Zhang Chenghai and co-founder Zhu Lingqiao, all previously worked in the R&D system of 3Sbio.

In 2016, this team resigned and founded MediGene Biotech, and then filed a patent (CN201710074949.X) related to its core investigational product MG-K10 in 2017. 3Sbio immediately filed a lawsuit, claiming that the patent was a service invention and its rights should belong to the former employer. In response, MediGene Biotech argued that the relevant technology was an independent R&D achievement of the team after their resignation.

In 2020, the Shanghai Intellectual Property Court ruled in favor of 3Sbio in the first instance. The court determined that the technical problems addressed by the disputed patent, the preparation methods adopted, and even part of the experimental data were strongly correlated with the regular work of Zhang Chenghai and others at 3Sbio. Meanwhile, MediGene Biotech failed to provide experimental data sufficient to prove its independent R&D process. This ruling assigned one of the key patents supporting the early development of MG-K10 to 3Sbio.

Yet this ownership dispute did not end there; on the contrary, it escalated again years later along with MediGene Biotech’s capitalization process.

In November 2025, at the critical stage when MediGene Biotech was sprinting for its IPO on the Hong Kong Stock Exchange, 3Sbio made another move and filed an invalidation request with the China National Intellectual Property Administration against another core patent of MediGene Biotech (Patent No.: CN202010309238.8). This patent, which had just been granted in November 2024, is regarded as one of the cornerstone patents for MG-K10. This move directly put MediGene Biotech’s most core intangible assets in uncertainty, casting a heavy shadow over its IPO journey and future commercialization.

Litigation proceedings show that the court had ruled in 2020 that the right to apply for the relevant patent belonged to 3Sbio, but it did not clarify the specific patent rights for MG-K10, laying the groundwork for a second lawsuit subsequently. This years-long dispute has concentratedly exposed the dilemma of defining technology ownership triggered by the mobility of core R&D personnel amid the wave of scientist entrepreneurship, as well as the pressure of competing for priority rights brought by the clustered R&D on popular drug targets.

If patents on drug targets are the birth certificates of innovative drugs, then patents on core production processes, crystal forms and formulations are the moats that secure market exclusivity after launch.

As compound patents expire and generic drugs crowd the market, deepening the defensive line from "compound patents" to "process patents" has become the key for original research pharmaceutical companies to extend product lifecycles. And this defensive battle has expanded from protecting the "city wall" of a single product to guarding the more upstream "arsenal" that defines future product pipelines.

The dispute between Huadong Medicine and Zhejiang Conba Pharmaceutical Co., Ltd. centers on the production process patent of fermented Cordyceps militaris powder—the core raw material of Huadong Medicine’s exclusive blockbuster "Bailing" product series, which once exceeded 3 billion yuan in annual sales.

In early 2024, when Conba’s competing product obtained marketing approval, Huadong Medicine immediately filed a lawsuit claiming approximately 111 million yuan in damages. The crux of the case lies in the overlapping determinations of administrative and judicial authorities. Although regulatory authorities required the competing product’s manufacturing process to be identical to that of Huadong Medicine, in December 2025, the Zhejiang Higher People’s Court dismissed Huadong Medicine’s claim in the first instance on the grounds that the product "does not fall within the scope of patent protection". The case is currently under appeal to the Supreme People’s Court.

Another more upstream battle over tool patents is unfolding between Harborside BioPharma and Biocytogen. The focus of their dispute is not a specific drug, but the source tool for drug development: a transgenic mouse platform used to generate fully human heavy-chain-only antibodies (HCAb).

Harborside BioPharma’s accusation of Biocytogen infringing its platform patents is essentially a fight for control over the "production mother machine" for a future pipeline of antibody drugs. The lawsuit went through common offensive and defensive moves such as jurisdiction objections and patent invalidation requests, and ultimately the patent was upheld as valid by the China National Intellectual Property Administration.

Meanwhile, in the dispute between Chipscreen Biosciences—the "first innovative drug stock"—and Nanjing Chia Tai Tianqing Pharmaceutical Co., Ltd., the latter has filed two patent invalidation applications against chidamide. However, Chipscreen Biosciences stated that it has built a comprehensive patent protection system for chidamide covering compounds, crystal forms, key processes, formulations and indications. Even if individual patents are breached, the overall patent jungle is robust enough to defend its market share.

The war over process patents has escalated to a higher dimension. Enterprises must not only protect the production secrets of their current products, but also bet on and defend the underlying technology platforms that determine the efficiency of future R&D.

If domestic patent wars are akin to civil wars, then when Chinese innovative pharmaceutical companies truly venture into the global market, they are faced with foreign wars dominated by the rule-makers.

According to the Survey on Overseas Intellectual Property Disputes of Chinese Enterprises (2024), there were 29 newly filed foreign-related patent litigation cases involving Chinese biopharmaceutical companies in 2024, of which 22 cases took China-based enterprises as defendants—and all these cases were initiated in the United States.

As a benchmark for overseas expansion, zanubrutinib, a BTK inhibitor, has become the focal point of a head-on confrontation between its developer BeiGene and AbbVie, marking a pivotal battle for Chinese innovative drugs entering the global arena against multinational pharmaceutical giants.

In 2019, this product achieved a zero breakthrough as the first China-originated innovative drug to be approved for marketing in the United States. With its U.S. sales volume surging (reaching 8.958 billion yuan in the first half of 2025), it was hit with a patent infringement lawsuit filed by Pharmacyclics, a subsidiary of AbbVie. The patent in question was AbbVie’s "’803 Patent", which was granted in 2023.

Notably, zanubrutinib had already obtained approval from the U.S. Food and Drug Administration (FDA) back in November 2019, while AbbVie’s ’803 Patent was filed in June 2020 as a follow-on patent intended to expand the scope of protection. This move is widely regarded as a classic strategy employed by multinational giants to delay competitors and maintain market dominance through patent litigation.

Instead of adopting a passive defensive stance, BeiGene directly initiated a Post-Grant Review (PGR) proceeding with the United States Patent and Trademark Office (USPTO) to challenge the validity of the ’803 Patent itself.

In April 2025, the USPTO issued a final written decision, ruling that all claims of the ’803 Patent were invalid due to being overly broad and lacking inventiveness. Eventually, AbbVie abandoned its appeal, and the two parties reached an agreement at the end of September 2025 to voluntarily withdraw all litigation. Since then, this major patent barrier to zanubrutinib in the U.S. market has been completely removed.

Nevertheless, in September 2024, AbbVie filed another patent lawsuit against BeiGene’s pipeline drug BGB-16673—a candidate designed to address BTK drug resistance—on the grounds of "misappropriation of trade secrets". Currently, this case is still pending.

The dispute surrounding Nefecon (budesonide enteric capsules) involving Everest Medicines has exposed the risks inherent in the License-in model’s rights and interests chain. Nefecon, a drug for the treatment of kidney diseases, was in-licensed by Everest Medicines from Sweden’s Calliditas Therapeutics in 2019. It was approved for marketing in China in 2023, with its sales exceeding 1 billion yuan in the first three quarters of 2025.

In December 2025, Hainan Herui Pharmaceutical’s generic version of the drug was approved, with the company committing not to launch it before the expiration of the patent term. However, pharmaceutical companies such as CSPC Pharmaceutical Group and Qilu Pharmaceutical submitted declarations claiming that their products "do not fall within the scope of patent protection", attempting to secure an early market launch. For Everest Medicines, this dispute is not only about market share but also involves the License-in rights and interests agreement with its overseas original developer. If generic drugs break through the patent barriers, it may even trigger disputes with the overseas licensor.

Looking at the patent offensives and defenses across China’s innovative pharmaceutical industry, the battles have evolved from competing for drug targets to safeguarding production processes and technology platforms, and further escalated to rule-based games in the global market—and yet the battlefields extend far beyond these areas. As early as the very initial stages of innovative drug R&D, when a complete patent "city wall" has not yet been erected, the scramble for trade secrets has already reached a white-hot intensity.

The flames of war have been ignited—nowhere to hide.