A report published last summer on validity challenges to pharma patents in China made waves in the industry with an eye-opening finding: among a sample of Patent Re-examination Board (PRB) challenges to pharma patents since 2015, nearly 75% resulted in at least one claim being invalidated. Even more surprising: for compound patents, claims for new molecules that form the bedrock of protection for drugs, the knockout rate was around 50%. Another article looking at 40 PRB cases from 2018 found that almost 44% of the challenged pharma patents had been invalidated in whole
The in-house pharma counsel points to China’s “draconian” rules on disclosing experimental data during the patent application process, and the extremely high bar set by the patent office for using post-filing data to defend from an invalidity challenge.
In 2006, China's National Intellectual Property Administration (CNIPA) got tough on sufficiency of disclosure, which is covered in Article 26.3 of the Patent Law. Guidelines issued that year told examiners that all the relevant experimental data demonstrating the use of a chemical or pharmaceutical invention must be included at the time of application, and applicants would not be allowed to use post-filing data to defend against rejections for insufficient disclosure. Post-filing data could also not be used to defend against invalidation. New patent examination guidelines of 2017 finally allowed patentees to submit post-filing data to the patent office.
Heather Lin, a lawyer with NTD Intellectual Property Attorneys in Beijing, thinks the change in CNIPA examination standards – not just on experimental data but on inventiveness – largely explains the high invalidation rates we are seeing. In the study showing the high 75% knockout rate, Lin says “As far as I noticed, the majority of the invalidated patents were filed in the late 1990s or early 2000s, at a time when Chinese patent office practice was not so strict in terms of inventive step or support issues.” She also notes that in those days, “foreign companies and even Chinese companies normally would not provide much experimental data in the specification because at the time the standard was not so strict.”
It is understandable, then, that by current standards, many patents may be easy to at least partially invalidate. This also could mean, however, that the invalidation rate will come down naturally over time, as patents filed after 2006 account for a greater share of the patents in force.