Comparison of efficacy and safety between two different irbesartan, generic vs branded, in the treatment of Korean patients with mild-to-moderate hypertension: an 8-week, multicenter, randomized, open-label, Phase IV clinical study

Purpose: This study aimed to compare the efficacy and safety of generic and branded irbesartan for 8 weeks in patients with mild-to-moderate essential hypertension. Patients and methods: We screened 221 patients with mild-to-moderate hypertension. After exclusion per study criteria, 177 subjects were randomized to receive 150 mg generic irbesartan (n=91) or branded irbesartan (n=86) as the intention to treat set. The primary efficacy endpoint of this study was the change in mean sitting diastolic blood pressure (SiDBP) from baseline to 8 weeks between the generic and branded irbesartan groups. The secondary efficacy endpoints were the change in mean SiDBP at Week 4 from baseline and the change in mean sitting systolic blood pressure (SiSBP) at Weeks 4 and 8 from baseline in both groups. All safety issues were evaluated. Results: At Week 8, the generic and branded irbesartan groups showed significantly reduced SiDBP (-10.3±8.0, -10.7±7.7 mmHg, all P<0.0001) compared with baseline values, and the mean between-group difference in SiDBP change after 8 weeks of treatment was -0.4±1.2 mmHg, showing the non-inferiority of generic irbesartan vs branded irbesartan. Furthermore, secondary efficacy, which was the mean change of SiDBP from baseline at 4 weeks, was comparable between the two groups (-9.4±8.1 vs -9.9±7.4 mmHg, P=0.69). There were no between-group differences in mean changes of SiSBP after 4 or 8 weeks of treatment (P=0.78, P=0.97, respectively), or in the incidence of adverse effects (16.7 vs 24.4%, P=0.20). Conclusion: Generic irbesartan treatment in patients with mild-to-moderate essential hypertension has shown effective antihypertensive effects comparable with the branded irbesartan treatment, with similar incidence of adverse effects.