Abstract
Purpose:
To evaluate whether baseline intraocular pressure (IOP) and prior therapy significantly influence efficacy of preservative free (PF)-tafluprost and PF-timolol in patients with OAG and OHT.
Methods:
The efficacy of PF-tafluprost 0.0015% q.h.s. and PF-timolol 0.5% b.i.d. was analyzed in 610 randomized OAG and OHT subjects in a three-month phase III study. Additional post hoc efficacy analyses were completed after patients were stratified by prior treatment and by baseline diurnal (mean of 8 AM, 10 AM, and 4 PM measures) IOP, ranging from <21 to ≥29 mmHg. "Low IOP" groups were defined as subjects having a baseline diurnal IOP <24 mmHg, and "High IOP" groups were defined as subjects having a baseline diurnal ≥26 mmHg.
Results:
After 12 weeks of treatment, mean diurnal IOP was lowered by 6.9 mmHg (28%) from a baseline of 24.9 mmHg in the PF-tafluprost group (N=298), and by 6.6 mmHg (27%) from a baseline of 24.7 mmHg in the PF-timolol group (N=312); the prespecified non-inferiority margin of 1.5 mmHg was met. Whether or not a patient was treatment naïve did not significantly change overall efficacy results for either treatment group (p≥0.839). However, in patients specifically naïve to prior prostaglandin treatment, PF-tafluprost (n=122) lowered IOP 7.2 mmHg (28%) compared to 6.5 mmHg (26%) by PF-timolol (n=140), a difference of 0.7 mmHg (p=0.044). Analyses of baseline IOP effects showed PF-tafluprost lowered IOP in the Low IOP group (n=125) by 5.6 mmHg (25%) compared to 9.1 mmHg (32%) for PF-tafluprost in the High IOP group, a difference of 3.5 mmHg (p<0.001). In the Low IOP groups, PF-tafluprost (n=125) and PF-timolol (n=132) lowered IOP 5.6 mmHg (25%) and 5.6 mmHg (25%), respectively (p=0.958). In the High IOP groups, PF-tafluprost (n=88) and PF-timolol (n=90) lowered IOP 9.1 mmHg (32%) and 7.9 mmHg (29%), respectively (difference between groups = 1.1 mmHg, p=0.020).
Conclusions:
In patients treated with PF-tafluprost and PF-timolol, the magnitude of reduction in IOP is dependent on the baseline IOP and may be influenced by prior topical treatments. Understanding the clinical importance of these factors is important when considering various treatment options for patient groups including treatment naïve subjects, individuals with high baseline IOP, and patients switching from other therapies.
Keywords: 466 clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials •
568 intraocular pressure