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.
Pfizer and Concert Pharmaceuticals are the two companies with the most advanced drugs for the indication of Alopecia Areata. Pfizer has press released results for their lead candidate PF-06651600 here Phase 2 Data in Alopecia Areata. The drug achieved a -33.6 reduction in SALT score at 24 weeks from a baseline of 88.1. Below are the percentages of reduction of SALT score points for both Pfizer drugs. PF-06651600 is the drug that the company will be taking forward into phase 3 clinical trials.
Table. Percentage of Patients with Better SALT
Scores at Week 24 Weeks
Improvement
in SALT ScorePF-06651600 Group %, PF-06700841 Group, %
30%
47.9
59.6
50%
37.5
48.9
75%
27.0
38.3
90%
25.0 31.9
100%
12.5 12.0
In the Columbia University phase 2 clinical trial Ruxolitinib for Alopecia Areata, 20mg bid dosing achieved good results based on the percentage of SALT improvement from baseline. At this time we do not know what the maximum dose that the FDA will allow Concert to run in clinical trials, as it is currently testing 8mg. CTP-543 is the deuterated version of Ruxolitinib currently in phase 2 clinical trials for Alopecia Areata. Thank you for reading.
Concert Pharmaceuticals will be entering a phase 2 clinical trial with CTP-543, for the indication of moderate to severe alopecia areata, in the first quarter of 2017. Proof-of-concept (POC), has already been indicated in a small phase 2 academic study by Columbia University with results of the auto-immune disease here JCI. We are estimating total revenue that CTP-543 could achieve if FDA approved for alopecia areata, based on some recent Dermatologic Drug Prices.
Up to 650,000 affected with alopecia areata U.S. any given time (Concert literature)
30% to 50% may have moderate to severe (195,000 to 325,000) US
Mid range population moderate to severe = 260,000 US
Market capture rate of 25% = 65,000 US moderate to severe
Price per tablet once daily = $23.33 or $700 per month
Peak revenue estimate $700 x 12 x 65,000 = $546 million
Risks to Assessment
Revenue split with another equally effective drug
The pool of potential patients is too high
Market capture rate of 25% too high
$700 monthly, or $23.33 per tablet
Insurance does not cover the indication
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.
