No more patent-evading IMD, needs new strategies

Following solifenacin trial, Champix trial reconfirms IMD becoming useless

Instead of ‘confirmation trial for scope of patent’, patent invalidation trial option emerges

Technically, the days of Korean pharmaceutical companies evading drug patent infringement by modifying the original’s salt base are over.

 

The Supreme Court’s ruling on the solifenacin (trade name: Vesicare) case in the beginning of the year first showed the signs of ending drug patent infringement with incrementally modified drug (IMD).

 

And it was reaffirmed on Dec.

 

20 with the Patent Court’s ruling for varenicline (trade name: Champix).

 

As for Korean companies, the time has come to seek for other strategy to challenge patent.

 

Experts say it would be more difficult than the old IMD strategy, but it is not say there isn’t any other way to challenge patent.

 

The other feasible strategy is to file an invalidation trial for each item to challenge the accusation of patent infringement.

 

Popular IMD strategy has become a thing of the past Pharmaceutical industry and legal experts say the Champix ruling was actually “expected”.

 

The majority of the experts predicted the solifenacin case would set a new precedent.

 

Only a handful of experts claimed the Supreme Court left a room for interpretation on the patent’s ‘practical equivalence’ and ‘technical obviousness of Person Having Ordinary Skill in the Art (PHOSITA)’.

 

Ultimately, judges made same decisions on following Januvia, Pradaxa, and Champix cases and reaffirmed the Supreme Court’s decision.

 

In August and September, the Patent Court ruled favorably for the original patentee of Pradaxa and Januvia, respectively, against IMDs.

 

Even in last year, IMD with switch in saline base has been the most common strategy for Korean companies to evade patent infringement and launch their generic early.

 

Hanmi Pharmaceutical’s Amodipin is a typical case.

 

By incrementally modifying Pfizer’s Norvasc in 2004, Hanmi Pharmaceutical has been generating tens of billions of won annually after commercializing the antihypertensive amlodipine generic.

 

The first alert went off when the original manufacturer, Astellas Pharma had requested litigation for cancellation of a trial decision on solifenacin IMD to the Patent Court in 2016.

 

Korean companies switched out succinate of the original solifenacin drug with fumarate.

 

The Patent Court recognized two combinations as different substances, and decided that solifenacin fumarate does not infringe the extended patent period.

 

However, the Supreme Court said the otherwise.

 

Following the court’s ruling, lower courts made a series of similar decisions and put the IMD strategy on shaky ground.

 

Pipeline strategy to change inevitably, then how about the originals?

 

Experts predict about 150 IMDs challenging respective patents would end up with similar ruling as the precedents.

 

Accordingly, Korean companies now have no choice but to shift pipeline strategy.

 

The time has come to let go of IMD, the relatively convenient option of evading patent infringement.

 

Considering medium-sized pharmaceutical companies challenged patents with IMDs, the intangible loss for giving up on IMD is expected to be significant.

 

Moreover, the original’s companies could start a domino of litigations.

 

Based on the precedents, the original companies are highly likely to file damage suit against IMDs for infringing their patents.

 

Since the overruling the previous solifenacin decision, Pfizer has requested for an injunction to ban sales of incrementally modified solifenacin, and the court has accepted the request.

 

Other original companies have not been reported to have requested the injunction.

 

The industry is keenly paying an attention on whether or not Pfizer would file the damage suit.

 

The legal experts see that the case would probably be favorable to Pfizer quoting the Supreme and Patent Courts’ decisions and Seoul Central District Court’s injunction.

 

Seeking for other options to challenge drug patent The industry-changing court ruling aside, it’s not to say Korean companies’ patent challenge is absolutely impossible from now on.

 

The patent system can be bypassed.

 

The Patent Court’s ruling on Betmiga (mirabegron) made a day before Champix case is a good example.

 

At the Patent Court on Dec.

 

18, 11 Korean companies, including Hanmi Pharmaceutical, Chong Kun Dang Pharmaceutical, JW Pharmaceutical, Ildong Pharmaceutical, Intro Biopharma, Alvogen Korea, Kyung Dong Pharm, Shinil Pharmaceutical, Han Wha Pharma and Shin Poong Pharmaceutical won the patent dispute against original company Astellas Pharma.

 

Meanwhile, Korean pharmaceutical companies are apparently trying new patent challenge strategies.

 

The existing IMD strategy was based on defensive confirmation trial for scope of a patent, which means it was challenging a small part of a whole patent.

 

Incremental modification of saline base was meant to challenge a part of extended period of drug patent.

 

On the other hand, the Korean companies filed an invalidation trial instead to challenge the patent.

 

If they win, the trial would nullify not partial, but the whole patent.

 

However, the trial is not to challenge drug patent, but to challenge novel use patent.

 

In other cases, some have challenged the extended period of drug patent with invalidation trial.

 

Hanmi Pharmaceutical and Ahn-gook Pharmaceutical won the invalidation trial against Novartis’ DPP-4 class diabetic treatment Galvus in last February.

 

The two companies have successfully revoked validity of the extend patent on Galvus.

 

A legal expert commented, “More than the Champix’ case, Betmiga’s trial attracted more attention as it was unpredictable.

 

Invalidation trial is surely complicated, but it is not impossible”.

 

“Defensively confirming the scope of a patent is now useless only for IMD, but other option could be used to challenge drug patents”, the legal expert added.