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.
 

Janus Kinase (JAK) Inhibitors

Janus Kinase Inhibitors - JAK's have shown to be successful in a variety of different disease indications.  The science of these inhibitors is still in the early stages of understanding.   They operate by inhibiting one or more of the family of enzymes, (JAK1, JAK2, JAK3, TYK2), and interfering with the signaling pathway.  They have shown to be successful in cancer and inflammatory diseases to date.  Concert Pharmaceuticals currently owns patents for the following three deuterated JAK inhibitors, with indications that each has shown to be effective in, prior to the company adding deuterium to the entity.

D-Ruxolitinib
Selectivity: JAK1,2 
Indication:  Myelofibrosis, Polycythemia Vera, Alopecia Areata  
Patent: 2032 US

D-Baricitinib
Selectivity: JAK1,2, TYK2
Indication: Rheumatoid Arthritis, Psoriasis
Patent: 2032 US

D-Momelotinib
Selectivity:  JAK1,2
Indication:
Patent: 2033 US

The non-deuterated versions of these JAK's have already shown proof-of-concept (POC), essentially reducing the risk for Concert to bring the drugs to market, for other or same, previously tested indications.  It's rare to have a full runway of patent years ahead, with clinically tested drugs, at your disposal. We'll follow the Janus Kinase landscape with any new findings in the future.  Thank you for reading. 

Ruxolitinib For Alopecia Areata

This academic Alopecia Areata clinical study by Columbia University, has finally been released in full to the public.  I highlighted what I believe are the important points to consider regarding this study.  The complete study can be found here JCI.