CNIPA Upholds AstraZeneca's Dapagliflozin Crystal Patent in Landmark Swiss-Type Claims Ruling
Key Insights
The China National Intellectual Property Administration (CNIPA (search)) affirmed the validity of AstraZeneca's dapagliflozin crystal form patent, marking the tenth successful defense against invalidation challenges in China.
The ruling establishes critical precedent for Swiss-type claims in pharmaceutical patents, limiting their scope to medical uses with specific substances as active ingredients rather than their use as raw materials.
The decision provides important guidance for both innovator companies in patent drafting strategy and generic manufacturers in challenging crystalline patent claims.
The China National Intellectual Property Administration (CNIPA (search)) has issued a landmark ruling affirming the validity of AstraZeneca AB's dapagliflozin crystal form patent, providing crucial guidance on the scope of protection for Swiss-type claims in pharmaceutical patents. The June 10, 2025 decision marks the tenth time the patent has successfully withstood invalidation challenges in China.
Patent Details and Dispute
The patent ZL200780024135.X covers crystalline solvates and complexes of dapagliflozin derivatives, specifically protecting the dapagliflozin (S)-propylene glycol hydrate structure known as the SC-3 Crystalline Structure. Dapagliflozin, AstraZeneca's blockbuster SGLT2 (search) inhibitor, is currently approved for treating chronic kidney disease (search), heart failure (search), and type 2 diabetes (search).
The central dispute focused on Claim 9, a Swiss-type claim protecting the use of the crystalline structure in manufacturing medicaments for treating diabetes (search), insulin resistance (search), hyperglycemia (search), hyperinsulinemia (search), elevated blood levels of fatty acids or glycerol, hyperlipidemia (search), dyslipidemia (search), obesity (search), or diabetic complications in mammals.
The petitioner argued that Claim 9 encompassed two distinct technical solutions: one where the medicament contains the SC-3 Crystalline Structure as the active ingredient, and another where the structure serves merely as raw material in preparation, with the final product containing a different dapagliflozin compound form.
CNIPA's Restrictive Interpretation
The CNIPA (search) approached the matter from multiple legal and technical dimensions, ultimately adopting a restrictive interpretation of the Swiss-type claim. The administration emphasized that Swiss-type claims were introduced as a workaround to Article 25 of Chinese Patent Law, which excludes "methods for diagnosis or for treatment of diseases" from patentable subject matters.
"The scope of protection of the Swiss-type claim be strictly limited to the medical use of the substance per se, banning any extension or expansionary interpretation that may result in erroneously covering the use of that substance as a starting material," the CNIPA (search) stated in its decision.
The administration noted that AstraZeneca had clarified through amendments during prosecution that Claim 9 intended to patent the medical use of the SC-3 Crystalline Structure product specifically. The CNIPA (search) determined that the patent's true contribution lies in proposing that the specific crystalline structure be directly applied as the active ingredient, rather than involving pharmaceutical use of transformed dapagliflozin compounds.
Industry Implications
The ruling carries significant implications for pharmaceutical patent strategy and generic drug development. For AstraZeneca's dapagliflozin franchise, the decision reinforces patent protection stability and may discourage future invalidation attempts from generic manufacturers.
More broadly, the decision establishes clear boundaries for Swiss-type claims in the pharmaceutical industry. The CNIPA (search) explicitly defined that such claims only cover medical uses "with specific substances as active ingredients," rather than their indirect use as raw materials.
For innovator pharmaceutical companies, the ruling emphasizes that patent drafting should prioritize substance over form, warning that excessively broad protection scope claims may endanger patent stability. The decision also provides generic drug companies with a clearer legal framework for challenging secondary claims in crystalline patents.
Balancing Innovation and Public Interest
The CNIPA (search)'s collegiate panel considered multiple factors in reaching its decision, including legislative intent, prosecution history, specification support, and the balance between public good and private patent rights. The administration concluded that a restrictive interpretation aligns with the patentee's actual technical contribution while maintaining appropriate patent scope boundaries.
The ruling represents a careful balance between protecting legitimate pharmaceutical innovation and preventing overly broad patent claims that could impede generic competition. By limiting Swiss-type claims to their intended scope, the decision maintains the delicate equilibrium between incentivizing drug development and ensuring eventual public access to medicines.