CinCor Pharma announces Phase 2 HALO trial does not meet primary endpoint

CinCor Pharma announced the topline results and completion of its Phase 2 HALO trial evaluating the efficacy and safety of baxdrostat in patients with uncontrolled hypertension taking up to two blood pressure medications at the maximally tolerated doses. Baxdrostat is a once daily potentially first-in-class, highly selective aldosterone synthase inhibitor. While HALO did not achieve statistical significance on its primary endpoint evaluating change from baseline in mean seated systolic blood pressure in the intention to treat population, a pre-specified subgroup analysis of non-Hispanic patients representing approximately 81-89% of the hypertension population in the United States, demonstrated a placebo-adjusted reduction in SBP of 12.6 mmHg at the 2 mg dose. The safety profile and tolerability of baxdrostat was consistent with previously reported Phase 2 BrigHtn data in resistant hypertension. HALO informs target populations for planned Phase 3 trials: HALO did not achieve its primary endpoint of statistically significant change from baseline in mean seated SBP versus placebo in the ITT population; however, statistically significant reduction in SBP in the prespecified non-Hispanic subgroup analysis was demonstrated; Hispanic or Latino patients represented 53% of the ITT population of the study; The non-Hispanic population of HALO represented 46% of the ITT population in the study but represents approximately 81-89% of the hypertensive population of the U.S. Safety and tolerability findings reinforce a consistent, and well-tolerated profile: No drug related serious adverse events observed and no major safety concerns were reported across all three dose cohorts tested after 8 weeks of treatment; No patient discontinued the study due to treatment-related adverse events; Baxdrostat demonstrated a favorable safety and tolerability profile with 3 cases of moderate hyperkalemia after 8 weeks of treatment none of which led to study discontinuation; Treatment-emergent serious adverse events were reported in 2 patients after 8 weeks of treatment; no SAE was deemed related to baxdrostat; 85% of patients that completed HALO enrolled in the ongoing open label extension trial evaluating the safety and efficacy of baxdrostat over 52 weeks. The HALO trial was a Phase 2 randomized, double-blind, placebo-controlled, multicenter, parallel-group, clinical trial designed to assess the safety and efficacy of baxdrostat in subjects taking up to two antihypertensive agents at their maximally tolerated dosages. The trial evaluated three active doses of baxdrostat compared to placebo control in 249 patients randomized across all four dosing cohorts, with 249 patients completing. The primary endpoint of the trial was the change in SBP after eight weeks of treatment. Background antihypertensive therapy was to be discontinued after these eight weeks, and patients only took baxdrostat at the 2.0 mg dose for four additional weeks in Part 2 of the trial to characterize monotherapy responses and to enable long-term safety assessments of the drug in the ongoing 52-week open label extension study that follows the HALO trial, which is expected to be completed in the second half of 2023.