CTP-656 & GLPG1837 Drug Comparison

The North American Cystic Fibrosis Conference began yesterday.  Concert presented some new data for CTP-656, and Galapagos released phase 1 data for drug GLPG1837 today. Below is new data for drug GLPG1837, and an early comparison of CTP-656 and GLPG1837.

GLPG 1837

The half life (t 1/2) of 1837 runs between 6 and 15 hours depending on the dosage.  I selected a middle of the range dosage of 500 mg used in the phase 1, for comparison to CTP-656, regarding plasma concentration, and their distinct profiles.  

Plasma concentration 500 mg 12 hours fed around 200 (ng/mL) 
http://www.glpg.com/rd-cystic-fibrosis

 

CTP-656

The half life of CTP-656 is 15 hours with a 150 mg dose.  

plasma concentration 150 mg 12 hours fed 1306 (ng/mL)

Kalydeco

The half life (t 1/2) of Kalydeco is around 11 hours for a 150 mg dose.

plasma concentration 150 mg 12 hours fed 412 (ng/mL)

SAFETY PROFILE

-Concert said CTP-656 was similar to Kalydeco at all dose levels, and well tolerated up to 300 mg.

-Galapagos 500 mg dosed twice daily with six participants, all experienced tiredness, and five experienced headache, in healthy subjects.  Galapagos says final safety data is pending.

Bottom Line:

From the data above, it looks like GLPG1837 will have to be dosed twice daily judging by the half life range of 6-15 hours, and Galapagos did not breakout each individual dose with half life. Two distinct drugs, as plasma levels with CTP-656 150 mg at 12 hours is substantially higher than GLPG1837 500 mg.  Concert believes that QD dosage (once daily) is possible with CTP-656.  The company still has to run a multiple ascending dose phase 1 trial, evaluating CTP-656 against Kalydeco.  Galapagos plans to initiate a phase 2 clinical trial for CF patients by the end of 2015. Thank you for reading.  No positions in Galapagos.