On April 24, CNIPA released its annual selection of Top 10 Typical Cases in Patent Reexamination and Invalidation — a tradition now in its seventeenth consecutive year. These cases serve as the closest thing China has to binding examination guidelines in practice: they signal how the CNIPA interprets patentability standards, and they directly shape prosecution and invalidation strategy.

This year's selection spans pharma, AI, standard-essential patents, marine biotech, and industrial materials. Several cases deserve close attention from international practitioners.

AI-generated evidence rejected in patent reexamination. In a reexamination case involving a tungsten-zirconium alloy preparation method, the applicant cited content generated by an AI large language model to support its inventiveness arguments. The CNIPA rejected this approach, holding that AI-generated outputs are influenced by data sources, algorithmic models, and prompting methods, and therefore cannot objectively reflect the state of the art as of the filing date or accurately represent the knowledge level of a person skilled in the art. This is, to our knowledge, the first explicit ruling addressing the evidentiary value of AI-generated content in Chinese patent reexamination proceedings — a development worth watching as AI tools become increasingly embedded in patent workflows.

First case dismissing an invalidation request for abuse of process. A wireless network patent invalidation case broke new ground: the CNIPA dismissed the request outright on the basis that it violated the principle of good faith and was not genuinely aimed at correcting improper patent grants. This is the first reported case in which an invalidation request was dismissed for violating the principle of good faith — CNIPA's clearest signal yet that invalidation proceedings should not be used for purposes other than correcting improper patent grants.

Pharma patentability standards refined. Three cases addressed core issues in pharmaceutical patent examination. A drug combination patent for cerebrovascular disease treatment clarified the evidentiary standards for synergistic effects at specific ratios. The sofosbuvir case — involving the world's first curative treatment for hepatitis C — affirmed protection covering multiple stereoisomeric configurations. A polymorph patent case for a c-MET inhibitor systematically addressed the standards for post-filing experimental data, an issue of persistent practical importance in life sciences prosecution.

AI application scenario patents get clearer rules. In a case involving audio-to-dynamic-image generation technology, the CNIPA applied the three-step inventiveness test while giving full consideration to application scenarios, model training methods, and other AI-specific factors — further developing examination standards for "AI+" patents in emerging sub-fields.

SEP invalidation and claim construction. An H.265 standard-essential patent case clarified how claim scope should be construed in invalidation proceedings, with careful delineation of the patent's innovative contribution in the video coding field.

Design patent invalidation: same feature, different weight. A bottle design patent was invalidated in a case that illustrates a nuanced point often underestimated in practice: identical design features may carry different visual weight depending on the product category. The CNIPA applied the "overall observation and comprehensive judgment" principle, and when read alongside a related "label" design case, the contrasting outcomes demonstrate how product context shapes the invalidation analysis.

Taken together, this year's cases reflect where China's patent examination practice is heading: tighter procedural discipline, clearer rules for AI and emerging technologies, and continued refinement of pharma patentability standards. For practitioners filing or challenging patents in China, this is the annual roadmap.