A 12-month interim analysis of the ROSSINI study, presented at the 12th Congress of the European Academy of Neurology (EAN) 2026, has provided robust real-world evidence for the efficacy and safety of AbbVie’s Vyalev (foslevodopa/foscarbidopa [LDp/CDp]) in managing advanced Parkinson’s disease (PD). The continuous subcutaneous infusion therapy demonstrated significant and sustained reductions in motor fluctuations, improvements in non-motor symptoms, and a manageable safety profile, offering a promising non-surgical treatment option for patients struggling with inadequately controlled symptoms on oral medications.
Main Facts
AbbVie’s investigational treatment, Vyalev, a continuous subcutaneous infusion therapy combining foslevodopa and foscarbidopa, has shown encouraging results in a 12-month analysis of the ongoing ROSSINI study. This real-world data, presented at the EAN Congress 2026, highlights Vyalev’s ability to significantly reduce motor fluctuations, specifically "OFF" time and dyskinesia, in patients with advanced Parkinson’s disease. Beyond motor symptoms, the therapy also demonstrated notable improvements in several non-motor symptoms that profoundly impact quality of life, such as sleep disturbances and pain. The safety profile observed was consistent with expectations for this type of therapy, with the majority of adverse events being infusion-site related and manageable. While quality of life improvements were modest overall, a subgroup of younger patients with shorter disease duration showed more pronounced benefits, suggesting potential advantages of earlier intervention. The study reinforces Vyalev’s position as a valuable non-surgical, device-aided treatment option, particularly for individuals seeking more stable symptom control without the need for invasive procedures.
Chronology of Vyalev’s Development and Study Findings
AbbVie’s journey with Vyalev has been marked by a commitment to addressing the unmet needs of advanced Parkinson’s disease patients. The drug, a combination of foslevodopa and foscarbidopa, is designed to deliver levodopa and carbidopa continuously via a subcutaneous infusion pump, aiming to provide more stable drug levels compared to oral formulations.
- October 2024: AbbVie secured U.S. Food and Drug Administration (FDA) approval for Vyalev, marking a significant milestone in its availability for patients. This approval was based on clinical trial data demonstrating its efficacy in managing motor fluctuations in advanced PD.
- June 29, 2026: The 12th Congress of the European Academy of Neurology (EAN) 2026 served as the platform for the presentation of the 12-month interim analysis of the ROSSINI study. This study, initiated to evaluate Vyalev’s real-world performance, provided crucial insights into its long-term safety and effectiveness in routine clinical practice.
- Ongoing ROSSINI Study (NCT06107426): This multi-country, prospective observational study is designed to track patients for three years, offering a comprehensive understanding of Vyalev’s impact over an extended period. The current interim analysis focused on Cohort A, comprising patients who were new to Vyalev treatment and had at least 12 months of follow-up data.
The data presented at EAN 2026 represents a critical juncture in understanding Vyalev’s role in the treatment landscape for advanced PD, moving beyond controlled clinical trial settings to assess its performance in the complexities of everyday patient care.
Supporting Data: Quantifying Vyalev’s Impact
The ROSSINI study’s 12-month interim analysis has yielded compelling quantitative data that underscore Vyalev’s therapeutic benefits. The study enrolled patients with advanced Parkinson’s disease, characterized by a mean age of 68.1 years, a mean disease duration of 12.1 years, and significant motor symptom burden with a mean "OFF" time of 4.8 hours and mean dyskinesia time of 3.2 hours at baseline.
Key Findings from the 12-Month Analysis:
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Reduction in Motor Fluctuations:
- OFF Time: Daily "OFF" time, a period when Parkinson’s symptoms worsen and medication is less effective, decreased substantially from a baseline of 5.2 hours to 3.0 hours at month 12. This represents a least-squares mean reduction of -2.2 hours, indicating a significant improvement in motor symptom control.
- Dyskinesia Time: Dyskinesias, involuntary writhing movements often caused by levodopa therapy, also saw a marked reduction. Dyskinesia time decreased from a baseline of 3.5 hours to 1.8 hours at month 12, with a least-squares mean change of -1.7 hours. This suggests better management of levodopa-induced side effects.
- Durability of Effect: Crucially, these improvements were observed early, with significant changes noted by week two of treatment, and were generally sustained throughout the 12-month period. This points to the potential for Vyalev to provide durable symptom control in a real-world setting.
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Improvements in Non-Motor Symptoms: The benefits of Vyalev extended beyond motor control to address debilitating non-motor symptoms that significantly impair quality of life.
- Parkinson’s Disease-Related Sleep Disturbances: Patients experienced sustained reductions in sleep disturbances, a common and distressing symptom for individuals with PD.
- Pain: Similarly, significant improvements were observed in PD-related pain.
- Gastrointestinal Dysfunction: The therapy also showed positive effects on gastrointestinal issues, another prevalent non-motor symptom.
- Freezing of Gait: Improvements were noted in freezing of gait, a particularly disabling symptom that can lead to falls.
- Clinical Significance: The largest observed changes were in PD-related pain and sleep disturbances, with both outcomes exceeding established minimal clinically important difference (MCID) thresholds. This is particularly noteworthy as these symptoms are often challenging to manage with conventional oral therapies and are major contributors to reduced quality of life in advanced PD.
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Quality of Life: The impact on quality of life presented a more nuanced picture.
- Overall Cohort: The 39-item Parkinson’s Disease Questionnaire (PDQ-39) summary index showed a modest improvement from baseline to month 12 across the entire cohort.
- Subgroup Analysis: A subgroup of younger patients with a shorter disease duration exhibited a more pronounced and statistically significant improvement in quality of life scores, decreasing from 31.3 at baseline to 24.0 at month 12. This suggests that initiating continuous subcutaneous levodopa therapy earlier in the disease course, before extensive progression, might yield greater patient-perceived benefits. However, this finding should be interpreted with caution due to the smaller sample size within this subgroup.
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Treatment Delivery and Dosing:
- Infusion Rate and Dose Stability: Vyalev infusion rates increased moderately in the first month and then stabilized, while the daily levodopa equivalent dose remained broadly consistent. This indicates the practical feasibility of maintaining a relatively stable dosing regimen after initial optimization, which is vital for long-term patient management and real-world adoption.
Safety Profile:
The safety profile of Vyalev in the ROSSINI study was consistent with expectations for continuous subcutaneous infusion therapy.
- Adverse Events: Any adverse event (AE) was reported in 74.1% of patients, severe adverse events (SAEs) in 22.9%, and serious adverse events (SAEs) in 28.4%. Adverse events leading to withdrawal occurred in 11.4% of patients.
- Most Frequent AEs: The most commonly reported treatment-emergent adverse events were infusion-site infection, infusion-site reaction, and hallucinations.
- Mortality: Six deaths were reported, all of which were deemed unrelated to the study treatment.
- Infusion Site Management: The findings highlight the importance of meticulous infusion-site management as a key consideration in the routine care of patients receiving Vyalev.
Official Responses and Expert Opinions
While the provided text does not contain direct quotes from AbbVie representatives or independent medical experts, the presentation of the ROSSINI study data at a major neurological congress like the EAN implies a strong endorsement from the research community. The fact that AbbVie gained U.S. approval for Vyalev in October 2024, prior to this detailed real-world data presentation, suggests that earlier clinical trials had already established a favorable risk-benefit profile.
The study’s design as a prospective observational study in "routine clinical practice" is crucial. It moves beyond the controlled environment of pivotal clinical trials to assess how the therapy performs in a broader and more diverse patient population, under real-world conditions. This type of data is highly valued by clinicians and payers alike, as it provides a more accurate reflection of a treatment’s impact in everyday practice.
The presentation at EAN 2026 signals that the scientific community is actively engaged with and evaluating Vyalev’s role in advanced Parkinson’s disease management. The focus on both motor and non-motor symptoms, as well as quality of life, reflects a comprehensive approach to understanding the multifaceted nature of the disease and the therapy’s potential to alleviate its burden.
Implications for Advanced Parkinson’s Disease Management
The interim findings from the ROSSINI study carry significant implications for the management of advanced Parkinson’s disease, a condition characterized by increasing motor complications and a substantial burden of non-motor symptoms that profoundly diminish quality of life.
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A Viable Non-Surgical Alternative: Vyalev’s ability to provide continuous levodopa delivery via a subcutaneous infusion system positions it as a strong non-surgical, device-aided treatment option. This is particularly advantageous for patients who may not be candidates for or prefer to avoid more invasive surgical interventions like deep brain stimulation (DBS), while still requiring more stable symptom control than oral medications can provide. The continuous delivery mechanism aims to smooth out the "ON" and "OFF" periods experienced with oral levodopa, leading to more consistent symptom management.
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Addressing the Non-Motor Symptom Burden: The observed improvements in non-motor symptoms such as sleep disturbances and pain are particularly impactful. These symptoms are often refractory to conventional treatments and are major contributors to the overall disability and reduced quality of life experienced by individuals with advanced PD. Vyalev’s capacity to positively influence these aspects of the disease could represent a significant therapeutic advancement.
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Potential for Earlier Intervention: The subgroup analysis suggesting greater quality of life benefits in younger patients with shorter disease durations hints at the possibility that earlier adoption of continuous levodopa therapy might maximize patient benefits. This warrants further investigation and could influence treatment guidelines in the future, encouraging a shift towards earlier consideration of such advanced therapies rather than delaying their use until symptoms become severely debilitating.
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Practicality in Real-World Settings: The data indicating stable infusion rates and levodopa equivalent doses after initial optimization is crucial for real-world adoption. It suggests that once a patient is initiated on Vyalev and their regimen is fine-tuned, the ongoing management is likely to be practical for both patients and healthcare providers. This reduces concerns about complex and frequently adjusted dosing, which can be a barrier to adherence and long-term success.
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Importance of Infusion Site Management: The consistent reporting of infusion-site reactions and infections underscores the need for diligent patient education and healthcare provider vigilance in managing the infusion site. This is a critical aspect of ensuring the safety and efficacy of any subcutaneous infusion therapy and will be a key focus for successful implementation of Vyalev in clinical practice.
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Limitations and Future Directions: Despite the promising results, the observational nature of the ROSSINI study necessitates caution in drawing definitive causal conclusions. Potential confounding factors and reliance on self-reported assessments are inherent limitations. The missing data for OFF and dyskinesia time in a portion of the cohort also requires careful consideration when interpreting these specific outcomes. Continued long-term follow-up of the ROSSINI study will be essential to confirm the durability of these benefits, further characterize the long-term safety profile, and identify patient subgroups that are most likely to derive the greatest therapeutic value from Vyalev. This ongoing research will be pivotal in refining treatment strategies and maximizing the potential of this innovative therapy for individuals living with advanced Parkinson’s disease.
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