Latest News in Parkinson Disease: Advantages of Sublingual Apomorphine, Disease-Modifying Strategies, and More

An overview of the latest news in Parkinson disease (PD) reported across MJH Life Sciences™.

Greater Motor Improvement Found in Sublingual Apomorphine Than Levodopa

An abstract presented at the American Academy of Neurology’s 73rd Annual Meeting, held virtually April 17-22, 2021, indicated that sublingual apomorphine led to greater motor improvement and a higher rate of responders at earlier time points when compared with levodopa.

Speaking on the abstract findings during an interview with NeurologyLive^®, lead study author Jennifer S. Hui, MD, assistant professor of Neurology at the Keck School of Medicine at the University of Southern California, said that the research further supports use of the sublingual agent in patients with PD who have a delayed ON response to levodopa. 

Designed to quickly treat OFF episodes, the sublingual apomorphine is absorbed through the oral mucosa and bypasses the gastrointestinal (GI) tract, which Hui noted can prove beneficial for those with PD, who commonly experience GI dysfunction.

Evaluating Disease-Modifying Strategies in PD

In designing potentially disease-modifying therapies in PD, an article by NeurologyLive^® highlighted the common roadblock of overcoming the efficacy already provided via levodopa. Recently, novel therapies, including immunotherapies, gene therapies, and tyrosine kinase inhibitors, have been developed to provide alternative approaches to address the wide array of symptoms present in PD.

In translating preclinical data to therapies, researchers say that the lack of specific biomarkers for PD continues to prove an obstacle in determining which patients may best benefit from each therapy. However, there are several patient populations with genetic loci associated with progression that have provided a target approach for subtyping, such as LLRK2–associated PD and GBA-associated PD.

Ultimately, researchers say while many agents show promise as potential disease-modifying therapies, greater assessment and knowledge of specific target engagement and related biomarkers in PD is warranted.

Phase 3 Study to Assess Subcutaneous Levodopa/Carbidopa Delivery

As the gold standard of care for PD, efficacy of carbidopa and levodopa has been found to wane as the disease progresses, with OFF episodes causing patients to feel slower, stiffer, and have more difficulty moving.

Currently, duopa serves as the first and only treatment providing 16 continuous hours of carbidopa/levodopa to help control motor fluctuations in advanced PD. However, an article by NeurologyLive^® highlights that this soon may change, with AbbVie, which had received FDA approval for duopa, announcing that it will be conducting a new phase 3 study of ABBV-951, an investigational soluble formulation of carbidopa/levodopa prodrugs in advanced PD.

Administered as a continuous subcutaneous infusion via external pump plus oral placebo capsules, ABBV-951 would provide an additional therapeutic option but without the associated issues of tube clogging or breakage present in duopa, which is administered in the small intestine through a tube placed during an outpatient procedure.