Abstract
Tiotropium is currently the only once-daily, long-acting muscarinic antagonist (LAMA) approved in the United States and other countries for the treatment of chronic obstructive pulmonary disease (COPD). Glycopyrronium has shown promise as a LAMA and was recently approved for once-daily maintenance treatment of COPD in the European Union. Here, we describe the in vivo preclinical efficacy and lung selectivity of a novel inhaled muscarinic antagonist, TD-4208 (biphenyl-2-ylcarbamic acid 1-(2-{[4-(4-carbamoylpiperidin-1-ylmethyl)benzoyl]methylamino}ethyl)piperidin-4-yl ester) and compare its profile to tiotropium and glycopyrronium. In anesthetized dogs, TD-4208, along with tiotropium and glycopyrronium, produced sustained inhibition of acetylcholine-induced bronchoconstriction for up to 24 hours. In anesthetized rats, inhaled TD-4208 exhibited dose-dependent 24-hour bronchoprotection against methacholine-induced bronchoconstriction. The estimated 24-hour potency (expressed as concentration of dosing solution) was 45.0 µg/ml. The bronchoprotective potencies of TD-4208 and tiotropium were maintained after 7 days of once-daily dosing, whereas glycopyrronium showed a 6-fold loss in potency after repeat dosing. To assess systemic functional activity using a clinically relevant readout, the antisialagogue effect of compounds was also evaluated. The calculated lung selectivity index (i.e., ratio of antisialagogue and bronchoprotective potency) of TD-4208 was superior to glycopyrronium after both single and repeat dosing regimens and was superior to tiotropium after repeat dosing. In conclusion, the in vivo preclinical profile suggests that TD-4208 has the potential to be a long-acting bronchodilator for once-daily treatment of respiratory diseases. Its greater functional selectivity for the lung in preclinical models may translate to an improved tolerability profile compared with marketed muscarinic receptor antagonists.
Footnotes
- Received January 29, 2013.
- Accepted May 16, 2013.
This work was completely funded and supported by Theravance, Inc.
This work was previously presented in abstract form as follows: Pulido-Rios MT, McNamara A, Kwan K, Martin W, Hegde S, Ji Y, and Mammen M (2009) TD-4208: a novel, lung-selective muscarinic antagonist with sustained bronchoprotective activity in preclinical models. Am J Respir Crit Care Med 179:A4557; and Pulido-Rios MT, McNamara A, Kwan K, Zamora F, Trumbull J, Obedencio GP, Jaw-Tsai S, Hegde S, and Martin WJ (2009) Bronchoprotective and antisialagogue effects of tiotropium after single and repeat dosing in rats. Am J Respir Crit Care Med 179:A4551.
- Copyright © 2013 by The American Society for Pharmacology and Experimental Therapeutics
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