"730 Heights" of generic drug patents

Author|totoro

After the official implementation of the patent link in China, the first statement of the patent information registration platform came from the statement of Tide Pharmaceuticals on piperacillil.
It made three types of declarations for the three patents registered for the original research drug, that is, waited for these patents to expire.
Listed (3 patents all expire in 2023)
.

Generic drugs of pibacillil in the United States

Five patents of piperacillil have been registered in the FDA Orange Book
.

At present, 5 generic drugs in the United States have obtained Tentative Approval after mid-2020 and have not yet been marketed
.

So why did Qilu Pharmaceutical choose 4 types of declarations for patent challenge in the United States, but choose not to go on the market temporarily in China, and Tide Pharmaceuticals also choose 3 types of declarations?

Potential threat of 730 crystal patent

Judging from the current US litigation situation, almost all companies have made “invalid or non-infringement” statements on the three patents 612,489,168, indicating that these three patents do not pose too much threat
.

Although Qilu Pharmaceutical submitted the ANDA earlier and did not need to declare the 730 patent, Pfizer still moved the 730 patent out of its lawsuit in 2021.
Pfizer believes that "Qilu submitted a listing application with full knowledge of the 730 patent, and it was unreasonable.
It is believed that it will be liable for the infringement of the 730 patent
.

Therefore, although Qilu's generic drug made 4 types of declarations on 3 patents, on the one hand, it failed to go on the market due to the pending litigation and the 30-month waiting period; on the other hand, even the threat of 3 patents was resolved.
, Still need to face the accusation of the 730 patent
.

In the database of the State Intellectual Property Office, a patent of the same family of 730 in China was retrieved, which was published before the generic drug application
.

From the current point of view, Pfizer is full of confidence in the role of the 730 patent
.

Enlightenment of generic drug patent link

(1) Differences in the courts of first instance between China and the United States

The courts of first instance jurisdiction for ANDA litigation in the United States are district courts, which may cause problems such as inconsistent trial standards and low efficiency
.

(2) Clarify the supplementary registration rules of the patent information platform

U.
S.
Orange Book patents can be supplemented for registration
.
Pfizer registered 730 patents at the end of 2020, 5 years after the first patent registration.
This is a big blow to companies that filed an ANDA application in early 2019 and are about to "surpass" the 30-month waiting period
.
China's patent information registration platform has not clarified whether it can supplement the registration of patents (only it can be clearly modified)
.
The supplementary registration of patents after the launch of the original research drug brings certain uncertainty to the generic drugs, and the later the patent registration may weaken the correspondence with the original research drug
.
It is hoped that China will further clarify the rules for the supplementary registration of patents after the launch of original research drugs, and give generic drug companies clear expectations for the market
.

(3) The significance of crystal patents

It is possible to register crystal form patents in the Orange Book of the United States, but China's patent information registration platform is currently unable to register crystal form patents
.
Whether to register a crystal-type patent is one of the focuses of disputes in the "Implementation Measures for the Early Resolution Mechanism for Patent Disputes (Draft for Comment)" jointly issued by the National Medical Products Administration and the State Intellectual Property Office in September 2020.
Some people believe that, Crystal type patents are important material patents.
Failure to register them in the patent information registration platform will not be conducive to the early resolution of disputes
.
Although the common opinion is that once the crystal patent enters the invalidation process, the possibility of maintaining its validity is extremely low (in other words, the inefficiency reaches more than 90%), this may also be one of the reasons why the patent information registration platform temporarily does not register the crystal patent.
; However, Xu Bo and others searched the patent reexamination and invalidation examination databases of the State Intellectual Property Office from February 14, 2020 to April 30, 2021, respectively, using the international classification numbers C07C, C07D, C07K, C12N, and A61K
.
Among the 65 decisions, the total invalidity rate for drug patents was 37%, the partial invalidity rate was 31%, and the maintenance effective rate was 32%.
Among them, 15 decisions were made for salt and crystal patents.
Ranked third in China, second only to compound patents and formulation patents, but its maintenance efficiency is the highest among all patent types (46.
7%)
.
The data of Xu Bo et al.
show that crystal form patents have become an important "defensive" patent besides the patents of the original drug compounds
.

Therefore, for innovative drug companies, it is of great significance to pay attention to the early layout of crystal forms of patents
.
Although crystal form patents cannot be included in the registration platform for the time being, use patents and composition patents that can be rewritten into crystal forms are included in the registration platform
.
For generic drug companies, it is necessary to circumvent the potential crystal patents of the original research drug or prepare for invalidation challenges in the early stage of research and development
.

Reference source:

① FDA

② USPTO PATENT FULL-TEXT AND IMAGE DATABASE

③ ORANGE BOOK

④ WestLaw database

③ State Intellectual Property Office Database

④ CDE patent information registration platform

⑤ News of Pfizer suing two Indian companies: https://gabionline.
net/generics/general/Pfizer-sues-Aurobindo-and-Dr-Reddy-s-over-Ibrance-palbociclib-generics

⑥ News about Pfizer suing Qilu:

https://lawstreetmedia.
com/health/pfizer-sues-to-block-generic-version-of-breast-cancer-drugs/

⑦ News about Pfizer suing Natco Pharma

https://lawstreetmedia.
com/health/pharmaceuticals/pfizer-alleges-patent-infringement-against-natco-pharma/

⑧[Empirical Research] Data Analysis of China's Drug Patent Invalidation after the "Sino-US Economic and Trade Agreement"

https://mp.
weixin.
qq.
com/s?src=11×tamp=1629377317&ver=3262&signature=6MW3H16JgWIiB51HMG*xU9MWQGa77Pm3JLuC0b0Thd4hL5F*aUa4*16gnRXQwHLz4qrvm4XiSikfGhe33fUd