Adenosine 2A Receptor Antagonism and AIH in ALS
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ClinicalTrials.gov Identifier: NCT05377424 |
Recruitment Status :
Recruiting
First Posted : May 17, 2022
Last Update Posted : March 21, 2023
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Condition or disease | Intervention/treatment | Phase |
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ALS | Drug: Consume 20mg of istradefylline Other: Low Oxygen therapy Drug: Placebo counterpart to the istradefylline drug Other: SHAM counterpart to low oxygen therapy. | Phase 1 Phase 2 |
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.
Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 40 participants |
Allocation: | Randomized |
Intervention Model: | Crossover Assignment |
Masking: | Triple (Participant, Care Provider, Outcomes Assessor) |
Primary Purpose: | Treatment |
Official Title: | Acute Adenosine Receptor Antagonism to Promote Breathing Plasticity in ALS |
Actual Study Start Date : | June 21, 2022 |
Estimated Primary Completion Date : | October 1, 2024 |
Estimated Study Completion Date : | December 31, 2024 |

Arm | Intervention/treatment |
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Experimental: AIH + istradefylline (AIH+IST)
Participants enrolled in this study arm will ingest a 20mg tablet containing istradefylline. Four hours later, participants will receive acute intermittent hypoxia (AIH). Breathing and pinch strength will be tested prior to taking the medication, and then immediately before, 60 minutes and 120 minutes after AIH. Participants will breathe 15 episodes/session of acute low oxygen. Air concentrations will be monitored to ensure delivery of 1-minute episodes of low oxygen, with 2 minutes room-air intervals. Respiratory rate, oxygen saturation, heart rate/rhythm, and blood pressure will be monitored throughout the session.
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Drug: Consume 20mg of istradefylline
Consume a single 20 mg istradefylline tablet
Other Name: Nourianz Other: Low Oxygen therapy 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.
Other Names:
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Active Comparator: Sham-AIH + istradefylline (sham+IST)
This is a sham counterpart to the low oxygen. Participants enrolled in this study arm will ingest a 20mg tablet containing istradefylline. Four hours later, participants will receive SHAM acute intermittent hypoxia (SHAM). Breathing and pinch strength will be tested prior to taking the medication, and then immediately before, 60 minutes and 120 minutes after SHAM. Participants will breathe 15 episodes/session of sham low oxygen, in which normal air is used. One-minute episodes of sham low oxygen are separated by 2 minutes room-air intervals. Respiratory rate, oxygen saturation, heart rate/rhythm, and blood pressure will be monitored throughout the session.
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Drug: Consume 20mg of istradefylline
Consume a single 20 mg istradefylline tablet
Other Name: Nourianz Other: SHAM 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.
Other Names:
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Active Comparator: AIH + placebo (AIH+CON)
This is a placebo counterpart to the istradefylline drug. Participants enrolled in this study arm will ingest a 20mg tablet containing microcrystalline cellulose. Four hours later, participants will receive acute intermittent hypoxia (AIH). Breathing and pinch strength will be tested prior to taking the medication, and then immediately before, 60 minutes and 120 minutes after AIH. Participants will breathe 15 episodes/session of acute low oxygen. Air concentrations will be monitored to ensure delivery of 1-minute episodes of low oxygen, with 2 minutes room-air intervals. Respiratory rate, oxygen saturation, heart rate/rhythm, and blood pressure will be monitored throughout the session.
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Other: Low Oxygen therapy
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.
Other Names:
Drug: Placebo counterpart to the istradefylline drug Consume a single microcrystalline cellulose
Other Name: Placebo |
Active Comparator: Sham-AIH + placebo (sham+CON)
This is a sham counterpart to low oxygen, and a placebo counterpart to the istradefylline drug. Participants enrolled in this study arm will ingest a 20mg tablet containing microcrystalline cellulose. Four hours later, participants will receive SHAM acute intermittent hypoxia (SHAM). Breathing and pinch strength will be tested prior to taking the medication, and then immediately before, 60 minutes and 120 minutes after SHAM. Participants will breathe 15 episodes/session of sham low oxygen, in which normal air is used. One-minute episodes of sham low oxygen are separated by 2 minutes room-air intervals. Respiratory rate, oxygen saturation, heart rate/rhythm, and blood pressure will be monitored throughout the session.
|
Drug: Placebo counterpart to the istradefylline drug
Consume a single microcrystalline cellulose
Other Name: Placebo Other: SHAM 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.
Other Names:
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- Treatment differences in the rate of adverse events. [ Time Frame: Through study completion (an average of 4-6 weeks) ]Any reported adverse events will be tracked and recorded.
- Change in resting tidal volume [ Time Frame: 120 minutes after AIH ]Averaged volume of breaths at rest
- Serum Istradefylline [ Time Frame: 4 hours post- istradefylline or placebo ]Blood test to measure change in level of istradefylline
- Serum Istradefylline [ Time Frame: 6 hours post- istradefylline or placebo ]Blood test to measure change in level of istradefylline
- Subject-reported involuntary movements [ Time Frame: 4 hours post- istradefylline or placebo ]Participants 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 ventilation [ Time Frame: 120 minutes post-intervention. ]Change in the average volume of air during a minute of resting breathing.
- Change in maximal voluntary pinch force [ Time Frame: 120 minutes post-intervention. ]Pinch force of the thumb will be evaluated in a seated position.

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.
Ages Eligible for Study: | 21 Years to 75 Years (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | Yes |
Inclusion Criteria:
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Non-smoking adults aged 21-75 years will be eligible to participate.
- Upon screening, eligible patients will have an
- ALS diagnosis (El Escorial diagnostic classifications of probable/definite ALS),
- vital capacity (VC) > 60% of predicted value, and
- ALS Functional Rating Scale (ALSFRS-R) score >30.
- Additionally, patients taking riluzole and/or edaravone must be on a stable dose for >30 days.
- 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
- are pregnant
- have an active respiratory infection,
- took antibiotics within 4 weeks,
- are diagnosed with another neurodegenerative disease,
- have symptomatic cardiovascular disease or dysrhythmias (resting tachycardia and hypertension),
- exhibit history or presence of hypoxemia or hypercapnia,
- presence of rest tachypnea (RR ˃30),
- have a BMI >35 kg/m2,
- have a seizure disorder,
- take respiratory inhalers daily for airway disease, or
- require external respiratory support while awake and upright, or
- supplemental oxygen at rest or at night.
- 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
- medications that may suppress ventilation, history of moderate renal impairment or severe hepatic impairment, and history of hallucinations or psychosis.
- Patients who cannot safety swallow thin liquids (required for administration of istradefylline and placebo) will also be ineligible.

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT05377424
Contact: Priscila Sales de Campos, PhD | (352) 273-6855 | psalesdecampos@ufl.edu |
United States, Florida | |
Clinical and Translational Research Building | Recruiting |
Gainesville, Florida, United States, 32610 | |
Contact: Juliette Clavier, BS 352-273-6855 juliette.clavier@phhp.ufl.edu |
Principal Investigator: | Barbara Smith | University of Florida |
Responsible Party: | University of Florida |
ClinicalTrials.gov Identifier: | NCT05377424 |
Other Study ID Numbers: |
IRB202101568 OCR41682 ( Other Identifier: UF OnCore ) |
First Posted: | May 17, 2022 Key Record Dates |
Last Update Posted: | March 21, 2023 |
Last Verified: | March 2023 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | No |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
ALS hypoxia breathing istradefylline |
Istradefylline Adenosine A2 Receptor Antagonists Purinergic P1 Receptor Antagonists Purinergic Antagonists |
Purinergic Agents Neurotransmitter Agents Molecular Mechanisms of Pharmacological Action Physiological Effects of Drugs |