Efficacy Analysis of Preservative-Free Tafluprost and Timolol in Open-Angle Glaucoma and OHT Patients in a Phase-III Study

Background: To determine whether baseline intraocular pressure (IOP) and prior therapy significantly influence efficacy of preservative free tafluprost (PFTAF) and timolol (PFTIM). Methods: The efficacy of PFTAF 0.0015% q.h.s. and PFTIM 0.5% b.i.d. was analyzed in 610 randomized OAG and OHT subjects in a double-masked, three-month study. Post hoc efficacy analyses were completed after stratifying patients by prior treatment and by baseline diurnal (mean of 8 AM, 10 AM, and 4 PM) IOP, including "Low"(<24 mmHg), "High"(=26 mmHg), and "Moderate"(25 to 27 mmHg) IOP groups. Results: PFTAF (N=298) lowered mean diurnal IOP 6.9 mmHg (28%, baseline 24.9 mmHg) vs. 6.6 mmHg (27%, baseline 24.7 mmHg) by PFTIM (N=312). Prior treatments did not influence efficacy except in patients (n=262) naive to prostaglandin therapy: PFTAF lowered diurnal IOP 7.2 mmHg (28%) vs. 6.5 mmHg (26%) by PFTIM (0.7 mmHg difference, p=0.044). Baseline evaluations showed PFTAF lowered IOP by 5.6 mmHg (25%) vs. 9.1 mmHg (32%) in the "Low"(n=125) and "High"(n=88) groups, respectively (3.5 mmHg difference, p<0.001). In the "Low"groups, PFTAF and PFTIM (n=132) each lowered IOP 5.6 mmHg (25%, p=0.958). In the "High"groups, PFTAF (n=88) and PFTIM (n=90) lowered IOP 9.1 mmHg (32%) and 7.9 mmHg (29%), respectively (1.1 mmHg difference, p=0.020). In "Moderate"patients, PFTAF (n=76) lowered mean diurnal IOP 7.8 mmHg (30.1%) vs. 7.2 mmHg (27.8%) by PFTIM (n=79). Conclusions: The magnitude of IOP reduction by PFTAF and PFTIM is dependent on baseline IOP and may be influenced by prior treatments.