Skip to content

Adenosine 2A Receptor Antagonism and AIH in ALS

Acute Adenosine Receptor Antagonism to Promote Breathing Plasticity in ALS

Status
Active, not recruiting
Phases
Phase 1Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05377424
Enrollment
40
Registered
2022-05-17
Start date
2022-06-21
Completion date
2026-08-31
Last updated
2026-03-27

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

ALS

Keywords

ALS, hypoxia, breathing, istradefylline

Brief summary

The purpose of this research study is to determine the effects of a medication, istradefylline, in conjunction with breathing air with reduced oxygen for short periods of time (called acute intermittent hypoxia, or AIH), on breathing. This project will study breathing in people with amyotrophic lateral sclerosis (ALS) and unaffected, age-matched adults. Istradefylline is prescribed to increase movement in people with other neuromuscular conditions. A recently completed study found that people with ALS took deeper breaths, 60 minutes after using AIH.

Detailed description

This repeated measures, placebo-controlled, randomized study will study feasibility and efficacy of istradefylline, an adenosine 2A receptor antagonist in conjunction with acute intermittent hypoxia (AIH). Participation in this study includes a screening for eligibility, plus 4 individual study visits separated by 1 week. The eligibility screening will include a review of medical history and medications, along with a breathing test and sleep study. Each participant will experience a different study condition on each of their 4 study visits: an "AIH + istradefylline" (AIH+IST) visit, and a "sham-AIH + istradefylline" (sham+IST) visit, an "AIH + placebo (AIH+CON)" visit, and a "sham-AIH + placebo" (sham+CON) visit. The visits will be in random order for each subject. Participants and the testing investigators will not be told which order the visits will be. Participants need to avoid exercise and caffeine and nicotine products for \>8 hours before each study visit. AIH + istradefylline visit: participants will take 20 mg of istradefylline. After a 4-hour break, participants will receive a 45-minute session of AIH, consisting of 15, one-minute periods of low oxygen (10% O2) with two-minute periods of normal oxygen (21% O2). Sham AIH + istradefylline visit: participants will take 20 mg of istradefylline. After a 4-hour break, participants will receive a 45-minute session of SHAM AIH, consisting of 15, one-minute intervals of normal oxygen (21% O2) with two-minute periods of normal oxygen (21% O2). AIH + placebo visit: participants will take 20 mg of microcrystalline cellulose. After a 4-hour break, participants will receive a 45-minute session of AIH, consisting of 15, one-minute periods of low oxygen (10% O2) with two-minute periods of normal oxygen (21% O2). Sham AIH + placebo visit: participants will take 20 mg of microcrystalline cellulose. After a 4-hour break, participants will receive a 45-minute session of SHAM AIH, consisting of 15, one-minute intervals of normal oxygen (21% O2) with two-minute periods of normal oxygen (21% O2). Venous blood samples will be collected at the start of each visit as general safety labs (complete blood count, uric acid, blood chemistry), and to assess levels of istradefylline levels in the blood. Additional blood tests 4 and 6 hours later will measure changes in serum istradefylline. The study will assess vital signs, patient-reported symptoms, resting breathing, strength of the breathing muscles, and maximal voluntary pinch force at the start of each visit. These measures will then be repeated 1 and 2 hours after AIH or SHAM. Throughout the AIH and SHAM interventions, respiratory rate, oxygen saturation, end-tidal carbon dioxide (CO2), heart rate, and blood pressure will be monitored. For the primary efficacy endpoint, the study will measure breath volume at the start of each visit, and 1 and 2 hours after the AIH and SHAM interventions. A linear mixed model will be used to compare differences in tidal volume. Main effects include treatment and time, with participants as random effects.

Interventions

DRUGConsume 20mg of istradefylline

Consume a single 20 mg istradefylline tablet

Breathing short periods of low oxygen, consisting of 15 episodes of 1 minute of breathing 10% oxygen, with 2 minutes of breathing 21% oxygen. 45 minutes total.

DRUGPlacebo counterpart to the istradefylline drug

Consume a single microcrystalline cellulose

OTHERSHAM counterpart to low oxygen therapy.

Breathing short periods of sham low oxygen, consisting of 15 episodes of 1 minute of breathing 21% oxygen, separated by 2 minutes of breathing 21% oxygen. 45 minutes total.

Sponsors

University of Florida
Lead SponsorOTHER
ALS Association
CollaboratorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Caregiver, Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
21 Years to 80 Years
Healthy volunteers
Yes

Inclusion criteria

1. Non-smoking adults aged 21-80 years will be eligible to participate. \- Upon screening, eligible patients will have an 2. ALS diagnosis (El Escorial diagnostic classifications of probable/definite ALS), 3. vital capacity (VC) \> 60% of predicted value, and 4. ALS Functional Rating Scale (ALSFRS-R) scores of 2 or greater for bulbar and respiratory items: swallowing, speech, salivation, dyspnea, orthopnea, and respiratory insufficiency. 5. Additionally, patients taking riluzole and/or edaravone must be on a stable dose for \>30 days. 6. Unaffected control subjects will be eligible if they have a vital capacity (VC) \> 60% of predicted value.

Exclusion criteria

Patient and control are ineligible if they 1. are pregnant 2. have an active respiratory infection, 3. took antibiotics within 4 weeks, 4. are diagnosed with another neurodegenerative disease, 5. have symptomatic cardiovascular disease or dysrhythmias (resting tachycardia and hypertension), 6. exhibit history or presence of hypoxemia or hypercapnia, 7. presence of rest tachypnea (RR ˃30), 8. have a BMI \>35 kg/m2, 9. have a seizure disorder, 10. take respiratory inhalers daily for airway disease, or 11. require external respiratory support while awake and upright, or 12. supplemental oxygen at rest or at night. 13. In addition, the following conditions are exclusionary for the use of istradefylline: routine use of CYP3A4 inducers (i.e. carbamazepine, phenobarbitol, rifampin, phenytoin, St. John's Wort, glucocorticoids) or 14. medications that may suppress ventilation, history of moderate renal impairment or severe hepatic impairment, and history of hallucinations or psychosis. 15. Patients who cannot safety swallow thin liquids (required for administration of istradefylline and placebo) will also be ineligible.

Design outcomes

Primary

MeasureTime frameDescription
Treatment differences in the rate of adverse events.Through study completion (an average of 4-6 weeks)Any reported adverse events will be tracked and recorded.
Change in resting tidal volume120 minutes after AIHAveraged volume of breaths at rest

Secondary

MeasureTime frameDescription
Serum Istradefylline4 hours post- istradefylline or placeboBlood test to measure change in level of istradefylline
Subject-reported involuntary movements4 hours post- istradefylline or placeboParticipants will use a 0-10 scale to report the intensity of any involuntary movements or tremors. (a higher number would correspond to more involuntary movements or tremors)
Change in minute ventilation120 minutes post-intervention.Change in the average volume of air during a minute of resting breathing.

Countries

United States

Contacts

PRINCIPAL_INVESTIGATORBarbara Smith

University of Florida

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Mar 28, 2026