The FDA has granted approval to Verona Pharma's ensifentrine oral inhalation suspension, marketed as Ohtuvayre, for the maintenance treatment of chronic obstructive pulmonary disease (COPD) in adult patients. This approval addresses a significant unmet need, as approximately half of COPD patients experience daily symptoms such as coughing, shortness of breath, and chest tightness. COPD affects an estimated 390 million people globally and is the third leading cause of death.
Mechanism of Action
Ensifentrine is a novel dual inhibitor of phosphodiesterase-3 (PDE3) and phosphodiesterase-4 (PDE4). By inhibiting these enzymes, ensifentrine increases intracellular levels of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), leading to downstream signaling effects that promote bronchodilation and reduce inflammation in the lungs. The drug reaches steady state by the third day of twice-daily dosing, with maximum plasma concentrations observed within 0.6 to 1.5 hours after administration. It has a terminal elimination half-life of 10.6 to 12.6 hours and is primarily metabolized by CYP2C9 and, to a lesser extent, by CYP2D6.
Dosage and Administration
The recommended dose of Ohtuvayre is 3 mg administered twice daily via oral inhalation using a standard jet nebulizer with a mouthpiece. It is crucial not to mix ensifentrine with other medications in the nebulizer, as physical compatibility has not been established. The drug is supplied as a unit-dose ampule containing 3 mg/2.5 mL (1.2 mg/mL) inhalation suspension.
Clinical Trial Efficacy
The efficacy of ensifentrine was demonstrated in the ENHANCE-1 (NCT04535986) and ENHANCE-2 (NCT04542057) trials. These were double-blind, parallel-group, placebo-controlled, randomized trials involving adult patients with moderate to severe COPD. Participants were randomized in a 5:3 ratio to receive either ensifentrine 3 mg via oral inhalation twice daily or placebo, while continuing their existing background COPD therapies. In ENHANCE-1, 30% of participants were using long-acting muscarinic antagonists (LAMAs), 18% used long-acting β-agonists (LABAs), and 20% used LABA/inhaled corticosteroids (ICSs). In ENHANCE-2, 33% used LAMAs, 7% used LABAs, and 15% used LABA/ICSs.
The primary endpoint in both trials was the change from baseline in the average forced expiratory volume in 1 second area under the curve (FEV1 AUC0-12h) post-dose at week 12. Ensifentrine demonstrated a statistically significant improvement in FEV1 AUC0-12h compared to placebo in both trials.
Safety and Warnings
Ohtuvayre is contraindicated in patients with hypersensitivity to ensifentrine or any of its components. It is not intended as a rescue therapy for acute bronchospasm symptoms, which should be treated with an inhaled short-acting bronchodilator. Paradoxical bronchospasm, a potentially life-threatening condition, may occur; if it does, ensifentrine should be discontinued immediately, and alternative treatment should be initiated. The drug is also associated with increased psychiatric adverse reactions, including suicidality, necessitating careful assessment of benefits and risks in patients with a history of depression or suicidal ideation.
There are limited data on the use of ensifentrine during pregnancy or lactation, and its safety and efficacy in pediatric patients have not been established. Caution is advised in patients with moderate or severe hepatic impairment due to increased systemic exposure. No dose adjustment is required for mild or moderate renal impairment, but the use of ensifentrine in severe renal impairment has not been studied. The most common adverse reactions reported include back pain, diarrhea, hypertension, and urinary tract infection.
