To determine whether LHW090 displays the clinical safety and efficacy profile to support further development in patients with resistant hypertension: i.e - To assess the safety and tolerability of LHW090 for 4 weeks on a background of conventional anti-hypertensive medications in patients with resistant hypertension. - To evaluate the effect of LHW090 on placebo-adjusted mean daytime systolic blood pressure (SBP) after 4 weeks in patients with resistant hypertension.