CTP-543 Patent Challenge by Incyte Corporation

On April 7th, Concert Pharmaceuticals CTP-543 (deuterated Ruxolitinb) patent was challenged for Inter Partes Review (IPR). The filing details are listed below.

Trial Number - IPR2017-01256
Filing Date - 4/7/2017
Patent # - 9,249,149
Title - DEUTERATED DERIVATIVES OF RUXOLITINIB
Patent Owner - CONCERT PHARMACEUTICALS INC.
Petitioner - INCYTE CORPORATION
Tech Center - 1600

We have written about what is considered obvious and referred to this well written article Deuterated Drugs: Unexpectedly Non Obvious?  Inevitably this was going to happen sooner or later, and perhaps sooner is overall better for the company. Below is a list of Pro's and Con's that I came up with.
Pro's

• The patent office issued a deuterated Ruxolitinib patent to Concert Pharmaceuticals.
• Concert's patent for deuterated ruxolitinib has Alopecia Areata listed as a potential indication that CTP-543 will be tested for. 
• Incyte Corporation's patent for Ruxolitinib, does not list Alopecia Areata as a target indication.
• Original Ruxolitinib patent has zero mention of deuteration in the patent. 
• The drug, per company press release exhibits a 20% reduction in dosing. A 16mg tablet of CTP-543 has similar dosing characteristics as a 20mg dosage of Ruxolitinib.   

Con's

• Outside of a 20% dosing advantage that CTP-543 has shown, the two drugs are dosed twice daily, as the half-life, and the metabolite profiles, are similar from Concert press releases. Challenge based on obvious.
•  The only other deuterated drug patent challenge, Auspex Pharma's Venlafaxline, stated in their litigation that the "deuterated venlafaxine claimed in the '317 patent however, has superior pharmacokinetic properties compared to venlafaxine, including increased half-life, reduced Cmax, and reduced inter-patient variability."

Bottom Line: 
We don't know which factor is seen as the most important in drug patent litigation. If it is specific for the drug indication intended use, then Concert should have a very strong case as Alopecia Areata is listed in their deuterated Ruxolitinib patent, and Incyte Corporation's patent does not list Alopecia Areata within their patent as an intended indication. On the other hand, if drug pharmacokinetic, metabolites, and dosing frequency differentiation is an important factor in determining the outcome, then Incyte may get the nod, as Concert has even stated the two drugs are similar, except for the 20% dosing reduction that CTP-543 has shown in phase 1 clinical trials. Thank you for reading.
 

Inter Partes Review and Drug Patents

There is an important case (Couzzo Speed Technologies V. Lee) scheduled for Monday April 25th, regarding a prior Inter Partes Review IPR, and a subsequent challenge to that outcome, which will be heard in the Supreme Court.  The patent in question has nothing to do with drugs, but an important precedent may be set with the case result.  The questions to be addressed:
1.  May the patent trial and appeal board apply the broadest reasonable interpretation of patent claims during an inter partes review hearing?
2.  Is the patent trial and appeal use of inter partes review judicially reviewable?

Companies such as Auspex, and Concert Pharmaceuticals, both which have a broad pipeline of deuterated patented drugs, may benefit from the inter partes review process, as a way to resolve potential patent issues should one occur.  An IPR, is intended to be quicker, more efficient, and less expensive for post-grant patent challenges.  Thank you for reading.

 

Deuterated Drugs

The September 5th edition of The Economist discusses some interesting facts about deutered drugs, and mentions Auspex and Concert Pharmaceuticals, of which both are the leaders in this area.  The potential for legal battles ensuing between the company applying deuteration, and the original owner of the drug may be overstated.  In Concert's case, they seek to partner with large pharma companies, creating a potential win/win situation, as the original drug owner gets an improved metabolic profile drug, the potential for less dosing and improved efficacy, with a longer patent life. 
In May we linked an article about what is obvious, or non-obvious as it relates to patent infringement here Patent Infrigement: Obvious or Nonobvious.  The placing of deuterium must be a skill or art in itself.  Some drugs could potentially have thousands of options to choose from, and that alone becomes a skill in itself that sets deuterium drugs apart from others.  Thank you for reading.
 

Patent Infrigement: Obvious or Nonobvious

As companies file for new chemical entity patents, the question of infringement on an existing drug becomes either obvious or nonobvious.  This link to an article titled Deuterated Drugs: Unexpectedly Nonobvious? is a nice paper by Ms. Kristen Buteau on what constitutes obvious from nonobvious inventions, and how it relates to drug companies such as Auspex, and Concert Pharmaceuticals.  The company that is applying for a new patent must present an unexpected difference between the claimed structures and the prior art. That difference may be the new drugs unexpected metabolism rate, other pharmacokinetic advantages, or a reduced dosing regimen compared to the prior drug.  But any unexpected difference must not be obvious, must be a skill or art in itself, such as the placing of deuterium on a drug that could have many options to choose from, potentially thousands, as the drug Cymbalta has.

Concert Pharmaceuticals is currently in a phase 1 trial to test d-Ivacaftor, which is the deuterated version of Ivacaftor, a drug that is currently approved for the treatment of Cystic Fibrosis.  Not only was the deuterated drug (d-Ivacaftor) patent filed before any mention of deuterium from Vertex Pharmaceutical, but the unexpected differences in pre-clinical studies suggest, that the deutered Ivacaftor version from Concert, improved pharmacokinetics to a high degree, both in-vitro and in-vivo, and may have the convenience of single 24 hour dosing compared to twice daily.  This phase 1 trial will show how (deuterated) d-Ivacaftor does in it's first in human clinical trial on safety, tolerability, and PK, versus the placebo Ivacaftor, and demonstrate whether some of the pre-clinical results are equally impressive in healthy human subjects. Thank you for reading.

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