Travoprost--a new prostaglandin analogue for the treatment of glaucoma

Abstract

Travoprost, a highly selective and potent analogue of the prostaglandin PGF(2)(alpha), has recently been approved and marketed as a topical ocular hypotensive agent for the treatment of ocular hypertension and glaucoma. Following absorption into the eye, the free acid form of travoprost interacts with the endogenous FP prostanoid receptor to enhance aqueous humor outflow and lower intraocular pressure (IOP). Travoprost is distinguished from other marketed prostaglandin analogues in that it is a full agonist at the prostaglandin receptor. It is also highly selective with little or no affinity for other prostanoid or non-prostanoid receptors in the eye. Travoprost provides robust lowering of IOP with little diurnal fluctuation and results in low target pressures in a large percentage of patients. In controlled clinical trials, travoprost 0.004% o.d. used as monotherapy produced greater IOP reduction than timolol 0.5% b.i.d. and equal or greater reduction than latanoprost 0.005%o.d. Travoprost 0.004% was also shown to be an effective adjunctive agent offering an additional 5 - 7 mmHg IOP reduction in patients inadequately controlled on timolol 0.5%. Subgroup analysis of a large Phase III trial revealed travoprost 0.004% to be significantly more effective at lowering IOP in African American patients by almost 2 mmHg compared to non-African Americans. Moreover, a higher percentage of African American patients responded to travoprost 0.004% and reached lower target pressures than with either latanoprost 0.005% or timolol 0.5%. Travoprost is a very stable compound, maintaining its efficacy following exposure to extremely low and high temperatures, repeated freezing and thawing and exposure to light. Throughout all clinical trials, travoprost was found to be safe and well-tolerated with very few (< 5%) discontinuations due to adverse events. Travoprost 0.004% represents a clinically significant advance for the treatment of glaucoma and ocular hypertension, offering superior IOP reduction and diurnal control, especially among African American patients, in a safe, well-tolerated, stable formulation.