The latest news on the new Parkinson’s drug Opicapone

Opicapone (Opicapone) is used to treat adults with Parkinson's disease. Opicapone blocks an enzyme involved in the breakdown of levodopa in the body called catechol-O-methyltransferase (COMT). Therefore, levodopa remains active longer. This helps relieve symptoms of Parkinson's disease, such as stiffness and slowness

Early resolution of symptoms in patients with Parkinson's disease (PD) is often managed by increasing the total daily dose of levodopa/dopa decarboxylase inhibitors (DDCI) or giving smaller, more frequent doses. If resolution symptoms persist, cause side effects, or treatment options are bothersome, consider adding a catecholamine-O-methyltransferase (COMT) inhibitor, dopamine agonist, or monoamine oxidase-B inhibitor.

The ADOPTION trial is a multicenter, randomized, open-label trial. In this study, patients with PD were randomly assigned to receive the COMT inhibitor opicapone 50 mg once daily or an additional 100/25 mg levodopa/DDCI dose. This additional dose may be given as a single 100/25 mg dose or divided into two 50/12.5 mg doses to be divided with any previous intake. This study aimed to compare the efficacy of opicapone and additional levodopa/DDCI in the treatment of early resolution of symptoms in patients with Parkinson's disease.

A total of 169 participants diagnosed with idiopathic Parkinson's disease who experienced predictable regression in less than 2 years were included The reduction in absolute mean daily off time was significantly greater with the use of Opicapone compared with the addition of levodopa (-62.1 minutes versus -16.7 minutes, respectively). Of note, at the end of the study, participants randomized to the opicapone group had a significantly higher equivalent daily dose of levodopa (751 mg vs 690 mg). A higher incidence of drug-related adverse events was observed in the opicapone group (25.3% vs 12.4%), and the incidence of serious adverse events was lower and similar between groups.

The results of the ADOPTION trial once again show that 50 mg of Opicapone can effectively improve early wear and tear symptoms in PD patients. However, it is important to consider the exploratory nature and context of the study. The most important point is that, although the comparison with levodopa is a positive aspect of this study, the dose of levodopa added to the comparison treatment appears to be suboptimal, as reflected in the increase in the equivalent daily dose of levodopa < that associated with opicapone.

In clinical practice, this study highlights that additional treatment with opicapone may be considered in patients who experience fluctuating motor responses. However, optimization of levodopa therapy is preferred as this appears to be associated with fewer side effects and lower costs. In addition, although opicapone has not been directly compared with treatment strategies other than levodopa, treatment options other than COMT inhibitors may be more effective and should be considered.