PCSK9 inhibition with orally administered NNC0385-0434 in hypercholesterolaemia: a randomised, double-blind, placebo-controlled and active-controlled phase 2 trial.

Background: Currently available injectable drugs that target proprotein convertase subtilisin/kexin type 9 (PCSK9) reduce serum LDL cholesterol and improve cardiovascular outcomes. This phase 2 study assessed NNC0385-0434, an oral PCSK9 inhibitor, in individuals receiving oral lipid-lowering therapy.

Methods: In this randomised, double-blind, placebo-controlled and active-controlled trial, 42 research sites across seven countries (Belgium, Germany, Greece, Japan, the Netherlands, Poland, and the USA) recruited individuals with established atherosclerotic cardiovascular disease (aged ≥40 years) or at high risk of atherosclerotic cardiovascular disease (aged >50 years), who had LDL cholesterol concentration of at least 1·8 mmol/L and were receiving maximum tolerated statins and stable lipid-lowering therapy. The study randomly allocated participants (3:1) with an interactive web response system to receive either NNC0385-0434 (15 mg, 40 mg, or 100 mg) once a day co-formulated with the oral absorption enhancer sodium N-[8-(2-hydroxybenzoyl)amino] caprylate (500 mg); placebo; or open-label evolocumab (140 mg) every 2 weeks administered subcutaneously. Blinding was performed within each dose level. The primary endpoint was percentage change from baseline in LDL cholesterol measured by β quantification at week 12. All randomly assigned participants received at least one dose of treatment and were included in both safety and efficacy analyses. The trial was registered on ClinicalTrials.gov, NCT04992065, and is completed.

Findings: Between Aug 16, 2021, and Jan 28, 2022, we randomly assigned 267 patients to one of the three NNC0385-0434 dose cohorts (n=53 per cohort), matching placebo (n=54), or open-label evolocumab (n=54). The study population comprised 82 (31%) women and 185 (69%) men; mean age was 64·3 years (SD 9·0). Baseline mean LDL cholesterol concentration was 2·7 mmol/L (SD 0·8). Treatment with NNC0385-0434 resulted in reductions in LDL cholesterol from baseline to week 12, of 32·0 percentage points (95% CI 20·9 to 43·0) in the 15 mg cohort, 44·9 percentage points (33·8 to 56·0) in the 40 mg cohort, and 61·8 percentage points (50·7 to 72·9) in the 100 mg cohort, compared with the placebo group (p<0·0001 for each). Patients treated with evolocumab had similar LDL cholesterol reductions (59·6% [SE 4·1] decrease from baseline) to patients receiving NNC0385-0434 100 mg (56·2% [4·0]). The estimated treatment difference between NNC0385-0434 100 mg and evolocumab 140 mg was 3·4 percentage points [95% CI -7·8 to 14·7]. The most frequently reported adverse event was COVID-19, which affected 31 (12%) of 267 patients, with similar numbers across treatment groups. Investigative sites reported gastrointestinal disorders as the most frequent treatment-related adverse event (26 patients and 35 events total in the three NNC0385 cohorts and one patient and one event each in the placebo and evolocumab cohorts). No deaths or treatment-related serious adverse events occurred.

Interpretation: This study showed excellent 12-week LDL cholesterol lowering efficacy and good patient tolerance of an oral PCSK9 inhibitor, NNC0835-0434, similar to an injectable drug. However, the sponsor chose to discontinue further development of NNC0835-0434 due to portfolio considerations.

Funding: Novo Nordisk.