New patent evasion strategy for Galvus follow-ons?

Releasing follow-on drug without an indication used to extend the original’s patent term

Even Ahn-gook’s preferential sales right can’t stop the patent-evaded drugs’ release

A creative strategy to evade patent is attracting the pharmaceutical industry’s attention.

 

If the strategy is found successful, pharmaceutical companies in Korea would be able to use it to evade the extended effective term of substance patent protection, as an alternative to the strategy of changing saline base of the original drug affirmed ineffective by the court.

 

According to an industry source on Jan.

 

12, Korean companies preparing follow-on drugs of dipeptidyl peptidase-4 (DPP-4) inhibiting anti-diabetes treatment Galvus has presented a unique patent evading strategy unlike preceding ones.

 

The companies are challenging the original’s patent by excluding an indication used as an evidence to extend the patent term.

 

For instance, the follow-on drug would omit one out of five indications of Galvus Met 50 mg/850 mg tablet, specifically the indication for ‘treating a patient when sufficient blood sugar level control is impossible with metformin monotherapy.’ The industry claims follow-on drug without the indication would not infringe the extended term of the patent as it was used to extend the Galvus’ substance patent term for 26 months and 23 days.

 

In fact, it was reported the vildagliptin-metformin 50 mg/850 mg tablet applied for approval on Dec.

 

24 last year, without the particular indication.

 

And apparently, the follow-on drug developers, Korea United Pharm and Hanmi Pharmaceutical have filed defensive confirmation trial for the right of Galvus patent with the same strategy.

 

The call would be made when Korea Intellectual Property Office (KIPO) decides whether or not to accept the follow-on drug developers’ claim.

 

If KIPO affirms the companies’ claim, then United Pharm and Hanmi Pharmaceutical would be able to release their follow-on drugs within this year.

 

It would be possible as Galvus’ other substance patent rejected from extension was expired Dec.

 

9 last year.

 

And also those two companies may launch products regardless of Ahn-gook Pharmaceutical’s generic approved with preferential sales rights.

 

After nullifying 187 days out of the extended patent term of 26 months and 23 days, Ahn-gook Pharmaceutical can legitimately start selling follow-on drug from Aug.

 

30, 2021.

 

The company also won the preferential sales right to exclusively supply the vildagliptin generic from Aug.

 

30, 2021 to May 29, 2022.

 

As a result, other drugs in the same class cannot be launched.

 

However, the exclusive sales right is not effective on drug that completely evaded extended patent term.

 

In other words, the follow-on drug developers could release their products before Ahn-gook Pharma.

 

And this is not the first time the strategy has been used.

 

Chong Kun Dang Pharmaceutical used the strategy to release benign prostatic hyperplasia (BPH) and hair loss treatment Avodart’s generic, Dutesmol, before the original’s extended patent was expired.

 

Initially, however, Dutesmol’s indication did not include treating BPH as it was an evidence to extend the original’s patent.

 

And after the substance patent was expired, the generic won the BPH indication and now the drug is available for prescription on treating BPH.

 

Galvus follow-on drug developers are likely to exclude indication used to extend the original’s patent, but they are also likely to seek for approval on the omitted indication when the patent expires completely.

 

As the old patent evasion strategy of changing saline base has been blocked by the Supreme Court’s decision made in January last year, the industry experts predict pharmaceutical companies in Korea have high chances of evading the extended term of the original’s patent protection by dropping an indication for their product.

 

Currently, pharmaceutical companies that commercialized follow-on drugs with switched saline base from the original overactive bladder medication Vesicare and smoking-cessation treatment Champix have suspended their sales due to the Court of Appeals’ decision to affirm patent infringement.