Janus Kinase Inhibitors for AA

The race is on for an effective and safe drug to treat Alopecia Areata. The two companies at the foremost of drug discovery are Pfizer with drug PF-06651600 and Concert Pharmaceuticals with CTP-543.  So how do the two JAK Inhibitor drugs stack up in limited clinical trials to date.
Columbia University 20 mg bid Ruxolitinib
n=12
% SALT Score Improvement (mean)
66.9%

Liu, King Study 10 mg bid Ruxolitinib
n=8
% SALT Score Improvement (mean)
61.2%

Pfizer PF-06651600
n=45
% SALT Score Improvement (mean)
38.1%                                                               
Next we will add the results of Concert's phase 2 clinical trial of CTP-543 with the 4mg and 8mg doses once press released expected fourth quarter. Thank you for reading.

Phase 2 CTP-543 Clinical Hold Lifted

Today Concert Pharmaceuticals announced that the phase 2 clinical trial of CTP-543 for Alopecia Areata will resume by the end of this month after a two month suspension. We initially wrote about this being one of three hurdles to be cleared CNCE: Three Hurdles to Clear.  The small downside is that the company will start the 24 week trial with the doses of only 4mg and 8mg, but with the potential to amend the protocol to explore higher doses. Prior to the suspension of the trial by the FDA, they were planning on using 4,8,12, and 16mg twice daily from the start. The FDA wants to take a measured approach for the development of using JAK inhibitors for various indications is what the company indicated. That coupled with the phase 1 clinical trials of CTP-543 that only lasted for 7 days of testing, makes sense.
The next hurdle to clear will be the pending sale of CTP-656 to Vertex, which is being considered by the FTC, whether it would be anti-competitive. I expect that second hurdle to clear in the next couple of months. 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.