Can Patients with Parkinson's Disease Use Dry Powder Inhalers during Off Periods?

Therapeutic effect of an inhaled levodopa dry powder formulation on off episodes in patients with Parkinson's disease

Background

Limited treatment options with a rapid onset of action are available to treat off episodes in Parkinson's disease (PD) patients. Therefore, the development of rapid onset formulations, for instance with levodopa, is warranted, which was the reason to investigate an inhalable formulation of levodopa.

Objectives

The primary objective was to determine the duration until maximum effect is reached of inhaled levodopa on the improvement of motor function of PD patients. The secondary objective was to compare the time until maximal effect and the maximal effect of inhaled levodopa versus oral levodopa.

Design

Open-label randomized two-way one-period crossover trial.

Methods

Nine PD patients in the 'off state' received one dose of inhaled levodopa (90 mg) from Cyclops® and one dose of levodopa orodispersible tablet (100 mg) on two consecutive days in a randomized order. A timed tapping test, Timed Up and Go test (TUG test) and Movement Disorders Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) III score were performed pre-dose and on set time points up to 90 min post-dose as measure for motor function. In addition, blood samples were taken for a pharmacokinetic evaluation (T max, C max and area under the concentration time curve (AUC) 0-3 h).

Results

The maximal effect of inhaled levodopa was reached at 30 min (tapping test), at 75 min (TUG test) and at 60 min (UPDRS III). The positive effect on the UPDRS was statistically significant within 20 min after inhalation. After oral administration, C max and AUC 0-3 h were found to be significant higher (p = 0.028 and p = 0.028, respectively) than after pulmonary administration. T max was achieved significantly (p = 0.028) faster after inhalation. The motor function examinations showed a similar maximum clinical improvement after pulmonary and oral administration and although not significant, inhaled levodopa results in a shorter median duration to maximum clinical effect for the TUG and timed finger-tapping test compared with oral administration (TUG: inhalation 55.0 and oral 67.5 min, timed finger-tapping test: inhalation 35.0 and oral 57.5 min). After the levodopa inhalation, there were no adverse events observed and no significant differences found in long-function parameters.

Conclusion

Inhaled levodopa from Cyclops® shows promising data as a rescue therapy for PD patients with off episodes, not responsive to the current oral therapies.

Trial registration

The study protocol was approved by the local ethics board 'Regionale toetsingscommissie patiëntgebonden onderzoek' (RTPO) in Leeuwarden, The Netherlands (approval number RTPO1019). The study was registered in in the Dutch trial register (LTR) with identification number NL6876. From 5 March 2024 on, the research data on onderzoekmetmensen.nl are known as 'Overview of Medical Research in the Netherlands' (OMON). This means the use of the name LTR has thus been dropped. Now, it is registered in the OMON with the same identification number (NL6876, Effectiveness of inhaled levodopa in PD | Research with human participants (onderzoekmetmensen.nl)). All patients provided written informed consent.

Safety and pharmacokinetics of multiple dosing with inhalable apomorphine (AZ-009), and its efficacy in a randomized crossover study in Parkinson's disease patients

INTRODUCTION

Apomorphine is used to treat OFF periods in Parkinson's disease (PD) patients. AZ-009 is a novel apomorphine formulation that delivers a thermally-generated aerosol to the deep lung via inhalation with a single breath.

METHODS

Part A was a randomized, placebo-controlled, double-blind study investigating the safety and pharmacokinetics of multiple ascending doses of AZ-009. PD patients (n = 24) received placebo or 2, 3 or 4 mg AZ-009 once daily for 5 days, followed by three times daily for 2 days with 2 h between doses. Part B was a double-blind crossover study in 8 PD patients who experience OFF periods. During an OFF state, patients received 4 mg AZ-009 and placebo on two consecutive days in a randomized order. MDS-UPDRS III and ON/OFF state were assessed pre- and post-dose.

RESULTS

Three times daily dosing with 2, 3 and 4 mg AZ-009 was relatively well tolerated with no apparent accumulation or changes in safety profile. Mild and transient throat irritation and cough were reported most often. AZ-009 was rapidly absorbed with median T_max between 1 and 2 min. When corrected for placebo response, the maximum effect of 4 mg AZ-009 based on MDS-UPDRS III scores was observed at 10 and 30 min post-dose with mean (SD) reductions of 6.8 (9.4) and 6.1 (9.1) points respectively. Whereas 0% of patients turned ON after placebo, 50% turned ON 10 min after 4 mg AZ-009 treatment.

CONCLUSION

AZ-009 is rapidly systemically absorbed and safe to dose three times daily. AZ-009 could provide a faster-acting and easier to use formulation than currently available therapies.

Optimizing Spray-Dried Porous Particles for High Dose Delivery with a Portable Dry Powder Inhaler

This manuscript critically reviews the design and delivery of spray-dried particles for the achievement of high total lung doses (TLD) with a portable dry powder inhaler. We introduce a new metric termed the product density, which is simply the TLD of a drug divided by the volume of the receptacle it is contained within. The product density is given by the product of three terms: the packing density (the mass of powder divided by the volume of the receptacle), the drug loading (the mass of drug divided by the mass of powder), and the aerosol performance (the TLD divided by the mass of drug). This manuscript discusses strategies for maximizing each of these terms. Spray drying at low drying rates with small amounts of a shell-forming excipient (low Peclet number) leads to the formation of higher density particles with high packing densities. This enables ultrahigh TLD (>100 mg of drug) to be achieved from a single receptacle. The emptying of powder from capsules is directly proportional to the mass of powder in the receptacle, requiring an inhaled volume of about 1 L for fill masses between 40 and 50 mg and up to 3.2 L for a fill mass of 150 mg.

Levodopa Inhalation Powder: A Review in Parkinson's Disease

Levodopa inhalation powder (Inbrija^®) is approved for the intermittent treatment of OFF episodes in patients with Parkinson's disease (PD) treated with levodopa/dopa-decarboxylase inhibitor (LD-DCI) in the EU and specifically with carbidopa/levodopa in the USA. The approved dosage is 84 mg taken as needed up to five times a day. Administered via a breath-actuated inhaler, this formulation enables levodopa to bypass the gastrointestinal (GI) tract and, instead, rapidly enter the bloodstream through the pulmonary system. In the 12-week, double-blind, placebo-controlled, phase III SPAN-PD trial, as-needed levodopa inhalation powder 84 mg improved motor symptoms during OFF periods in PD patients (aged 30-86 years) treated with levodopa and carbidopa or benserazide. The likelihood of achieving an ON state 60 min postdose was significantly higher in the levodopa inhalation powder than the placebo group, with most patients in the levodopa inhalation powder group experiencing improvements in PD symptoms. Findings from longer-term, 52-week phase III studies were consistent with those from the SPAN-PD trial with regards to the treatment of OFF episodes. Levodopa inhalation powder was generally well tolerated and did not noticeably affect pulmonary function in PD patients. Providing a nonintrusive, convenient treatment method, levodopa inhalation powder is a promising option for the intermittent treatment of OFF episodes in patients with PD treated with a LD-DCI.

Inhaled levodopa for intermittent treatment of OFF episodes in patients with Parkinson's disease

Introduction: Many patients with advanced Parkinson's disease (PD) have inadequate control of motor symptoms despite optimized treatment. Predictable and unpredictable OFF periods severely interfere with the quality of life. A drug that easily and rapidly reverts the OFF state is still needed. Subcutaneous apomorphine, the only approved drug for this indication, although efficacious, is not widely used probably due to its potential side effects and complicated administration.Levodopa is the most efficacious drug for the treatment of PD motor symptoms. However, issues related to the oral route and intestinal absorption in later disease stages render this route lengthy and inefficacious.Areas covered: Literature on the development of an inhaled formulation of levodopa has been reviewed. Significant advances in the field of pulmonary delivery systems and in dry powders have enabled the development of a new formulation of levodopa that can be inhaled and adequate blood levels rapidly achieved, bypassing intestinal absorption. Several clinical trials have reported efficacy, safety, and tolerability data. Some pulmonary-related adverse events have been reported but are mostly mild.Expert opinion: This new way of administering levodopa is likely to be very welcome and may fill a gap for OFF rescue treatments, at least for some patients.

Pharmacokinetics and tolerability of inhaled levodopa from a new dry-powder inhaler in patients with Parkinson's disease

Background

Inhaled levodopa may quickly resolve off periods in Parkinson's disease. Our aim was to determine the pharmacokinetics and tolerability of a new levodopa dry-powder inhaler.

Methods

A single-centre, single-ascending, single-dose-response study was performed. Over three visits, eight Parkinson's disease patients (not in the 'off state') received by inhalation 30 mg or 60 mg levodopa, or their regular oral levodopa. Maximum levodopa plasma concentration (C _max), time to maximum plasma concentration (T_max) and area under the concentration time curve 0-180 min were determined. Spirometry was performed three times at each visit.

Results

After inhalation, levodopa T _max occurred within 15 min in all participants, whereas after oral administration, T _max ranged from 20 min to 90 min. The bioavailability of inhaled levodopa without carboxylase inhibitor was 53% relative to oral levodopa with carboxylase inhibitor. No change in lung-function parameters was observed and none of the patients experienced cough or dyspnoea. No correlation was observed between inhalation parameters and levodopa pharmacokinetic parameters.

Conclusion

Inhaled levodopa is well tolerated, absorbed faster than oral levodopa, and can be robustly administered over a range of inhalation flow profiles. It therefore appears suitable for the treatment of off periods in Parkinson's disease.

Profile of inhaled levodopa and its potential in the treatment of Parkinson's disease: evidence to date

Inhaled levodopa is a newly emerging therapeutic option in the treatment of "off " symptoms associated with Parkinson's disease (PD). Its mode of delivery offers more rapid absorption of levodopa and shorter onset of clinical benefit compared to oral formulations, and has been shown to be feasible for use in patients with PD experiencing worse motor function due to declining plasma levodopa levels. Clinical development of this compound is supported by preclinical, Phase I-III, long-term-safety studies and studies in special populations, including otherwise-healthy asthmatics and smokers. These investigations demonstrated that the drug is well tolerated without risk of long-term (up to 1 year) changes in pulmonary function or spirometry measures. The most common side effects among PD patients were a mild cough, upper respiratory tract infection, nausea, sputum discoloration, and dyskinesia. Inhaled levodopa offers a different administration method and side-effect profile from the currently available options for rescue therapy for Off periods in PD, though comparative studies have not been performed. The drug is presently under review by the US Food and Drug Administration.

Pulmonary Safety and Tolerability of Inhaled Levodopa (CVT-301) Administered to Patients with Parkinson's Disease

Background: CVT-301, an inhaled levodopa (LD) formulation, is under development for relief of OFF periods in Parkinson's disease (PD). Previously, we reported that CVT-301 improved OFF symptoms relative to placebo. In this study, we evaluate pulmonary function in patients treated with a single dose of CVT-301 or placebo for 3 hours, or received multiple doses/day for 4 weeks.

Methods: As part of two phase 2 studies, pulmonary safety and tolerability of CVT-301 were evaluated in PD patients experiencing motor fluctuations (≥2 hours OFF/day), Hoehn and Yahr stage 1–3, and forced expiratory volume in 1 second/forced vital capacity ratio ≥75% of predicted (in ON state). In study A, patients received single doses of oral carbidopa/LD and each of the following via the inhaled route: placebo and 25 and 50 mg LD fine particle dose (FPD) CVT-301. In study B, patients received up to 3 inhaled doses/day of 35 mg (weeks 1–2) and 50 mg LD FPD CVT-301 (weeks 3–4) versus placebo. Assessments included spirometry and treatment-emergent adverse events (TEAEs).

Results: In study A, (n = 24) mean age ± standard deviation was 61.3 ± 7.4 years, mean time since diagnosis was 10.5 ± 4.6 years, and mean duration of LD treatment 8.4 ± 3.7 years. Assessment of pulmonary function (predose to 3 hours postdose) showed that spirometry findings were within normal ranges, regardless of treatment groups, or motor status at screening. In study B, (n = 86) mean age was 62.4 ± 8.7 years, time since PD diagnosis was 9.4 ± 3.9 years, and duration of LD treatment 7.8 ± 3.9 years. Longitudinal assessment of pulmonary function over 4 weeks showed no significant difference in spirometry between CVT-301 versus placebo groups. In both studies, the most common CVT-301 TEAE was mild-to-moderate cough (study A: 21%; study B: 7% vs. 2% in placebo). Other common TEAEs in study B were dizziness and nausea.

Conclusion: Acute and longitudinal assessment of pulmonary function showed that CVT-301 treatment was not associated with acute airflow obstruction in this population. CVT-301 was generally safe and well tolerated.

Advances in Audio-Based Systems to Monitor Patient Adherence and Inhaler Drug Delivery

Hundreds of millions of people worldwide have asthma and COPD. Current medications to control these chronic respiratory diseases can be administered using inhaler devices, such as the pressurized metered dose inhaler and the dry powder inhaler. Provided that they are used as prescribed, inhalers can improve patient clinical outcomes and quality of life. Poor patient inhaler adherence (both time of use and user technique) is, however, a major clinical concern and is associated with poor disease control, increased hospital admissions, and increased mortality rates, particularly in low- and middle-income countries. There are currently limited methods available to health-care professionals to objectively and remotely monitor patient inhaler adherence. This review describes recent sensor-based technologies that use audio-based approaches that show promising opportunities for monitoring inhaler adherence in clinical practice. This review discusses how one form of sensor-based technology, audio-based monitoring systems, can provide clinically pertinent information regarding patient inhaler use over the course of treatment. Audio-based monitoring can provide health-care professionals with quantitative measurements of the drug delivery of inhalers, signifying a clear clinical advantage over other methods of assessment. Furthermore, objective audio-based adherence measures can improve the predictability of patient outcomes to treatment compared with current standard methods of adherence assessment used in clinical practice. Objective feedback on patient inhaler adherence can be used to personalize treatment to the patient, which may enhance precision medicine in the treatment of chronic respiratory diseases.

Non-oral dopaminergic therapies for Parkinson's disease: current treatments and the future

Dysfunction of the gastrointestinal tract has now been recognized to affect all stages of Parkinson’s disease (PD). The consequences lead to problems with absorption of oral medication, erratic treatment response, as well as silent aspiration, which is one of the key risk factors in developing pneumonia. The issue is further complicated by other gut abnormalities, such as small intestinal bacterial overgrowth (SIBO) and an altered gut microbiota, which occur in PD with variable frequency. Clinically, these gastrointestinal abnormalities might be associated with symptoms such as nausea, early-morning “off”, and frequent motor and non-motor fluctuations. Therefore, non-oral therapies that avoid the gastrointestinal system seem a rational option to overcome the problems of oral therapies in PD. Hence, several non-oral strategies have now been actively investigated and developed. The transdermal rotigotine patch, infusion therapies with apomorphine, intrajejunal levodopa, and the apomorphine pen strategy are currently in clinical use with a few others in development. In this review, we discuss and summarize the most recent developments in this field with a focus on non-oral dopaminergic strategies (excluding surgical interventions such as deep brain stimulation) in development or to be licensed for management of PD.