Inhaled levodopa powder offers rapid relief for sudden symptom returns according to new clinical data presented at the World Parkinson Congress 2026

New clinical analyses presented at the World Parkinson Congress 2026 in Phoenix, Arizona, have confirmed that an on-demand levodopa inhalation powder, known as Inbrija, provides rapid and consistent movement benefits for people experiencing sudden symptom returns. The data, shared by Merz Therapeutics, highlights the treatment as a reliable option for managing these highly disruptive health fluctuations. A pooled analysis of 437 people across three Phase III clinical trials evaluated how effectively the inhaled powder works at different stages of the condition. The study compared individuals who had been experiencing these medication fluctuations for less than two years with those who had been dealing with them for two years or longer. Both groups showed rapid and consistent physical improvements, achieving significant and nearly identical average reductions in standard clinical movement scores. A separate long-term safety analysis tracked the tolerability of the inhalation powder over 60 weeks of continuous use. The findings showed that the most common side effects were a cough and throat irritation, which were predominantly mild and did not increase in severity with higher doses. Over the course of the 60-week period, the probability of remaining completely free from a treatment-related cough was 84.7 per cent. The clinical utility of this rapid-acting treatment is underscored by a second study presented at the congress, which mapped the sheer scale of the challenges these fluctuations present. A comprehensive literature review identified 132 distinct physical, mental, and quality-of-life impacts associated with these periods, commonly known as OFF episodes. These episodes occur when regular scheduled medications wear off, leading to a re-emergence of symptoms. The research emphasizes that the burden extends far beyond visible physical changes like tremors and stiffness. Invisible non-motor symptoms, including fatigue, memory difficulties, and anxiety, were found to be just as debilitating as the physical changes, reinforcing the critical clinical need for rapid, reliable on-demand therapies to help people maintain control over their daily lives.