Phase 2, Randomized, Double-Blind, Placebo-Controlled Study of CRD-740, a PDE9 Inhibitor, in Chronic Heart Failure

Area of Science:

• Cardiovascular Pharmacology
• Drug Discovery and Development
• Heart Failure Pathophysiology

Background:

• Natriuretic peptide receptor activation, crucial for cardiovascular homeostasis, is mediated by cyclic guanosine monophosphate (cGMP).
• Phosphodiesterase 9 (PDE9) degrades cGMP, making its inhibition a therapeutic target to boost intracellular cGMP signaling.
• Targeting PDE9 offers a potential strategy to augment the beneficial effects of the natriuretic peptide pathway in cardiovascular diseases.

Purpose of the Study:

• To evaluate the efficacy of the oral PDE9 inhibitor CRD-740 in modulating plasma and urinary cGMP levels.
• To assess the safety and tolerability of CRD-740 in patients diagnosed with heart failure and reduced ejection fraction (HFrEF).
• To explore the potential of CRD-740 to enhance cGMP signaling in patients receiving standard heart failure therapies, including sacubitril/valsartan.

Main Methods:

• A Phase 2, randomized, placebo-controlled trial involving 60 patients with HFrEF (NYHA class II/III, ejection fraction ≤40%).
• Participants received either CRD-740 (escalating doses) or a placebo for 12 weeks, with plasma cGMP change at week 4 as the primary endpoint.
• Pharmacodynamic assessments included measurements of plasma and urinary cGMP, alongside monitoring of blood pressure and adverse events.

Main Results:

• CRD-740 significantly increased plasma cGMP levels by 19.1% at week 4 compared to placebo (P=0.003).
• Elevated urinary cGMP levels were observed with CRD-740 treatment at multiple time points (day 1, week 2, week 4).
• The drug was well-tolerated, with no significant differences in blood pressure, hypotension, or serious adverse events between groups.

Conclusions:

• Oral PDE9 inhibition with CRD-740 is a safe and effective strategy for increasing cGMP levels in HFrEF patients.
• CRD-740 demonstrates potential to augment natriuretic peptide signaling, offering incremental benefits beyond existing heart failure treatments like sacubitril/valsartan.
• These findings support further investigation of CRD-740 as a novel therapeutic agent for heart failure management.