Respiratory DepressionPhase 2NCT06137638
ENA-001 for Post Operative Respiratory Depression (PORD)
A Phase 2 study testing ENA-001 in people with Respiratory Depression, run by Enalare Therapeutics Inc..
Trial summary
This study is a Phase II, randomized, placebo-controlled, double-blind trial in 200 subjects having general anesthesia for major elective surgery with postoperative pain management to evaluate the efficacy, safety and tolerability of ENA-001 as a therapy to prevent post operative respiratory depression. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Respiratory Depression
- What is being tested?
- ENA-001
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 200 participants
- Where
- No sites listed yet
- Study dates
- 15 Dec 2026to 15 Jul 2027
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Willing to give written informed consent for the trial and willing/able to adhere to study procedures.
- Scheduled to undergo a major elective surgery, including abdominal, laparoscopic, nephrology, thoracic (non-cardiac), orthopedic (e.g., shoulder and ankle surgery), where the subject will be transferred to recover in the general postanesthesia recover unit (PACU) and extubation will be performed in the operating room or PACU.
- Undergoing surgical procedure with a intraoperative requirement of ≥ 250 µg of fentanyl; Enrolled base on expected pain management to necessitate ≥ 250 µg of fentanyl intraoperatively.
- Male and female, ≥18 years of age.
- American Society of Anesthesiologists (ASA) physical status classification 1-3.
- Have no clinical or electrocardiographic signs of ischemic heart disease as determined by the Investigator. The Screening 12 lead ECG conduction intervals must be within gender specific normal range (e.g., QTcF female \< 450 msec QTcF males \< 430 msec, PR interval ≤ 220 msec). ECGs are to be judged by the investigator or sub-investigator as per standardized procedures.
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- Clinical laboratory tests (blood hematology, blood chemistry, coagulation and urinalysis) must not include any significant clinical abnormalities.
- Vital sign measurements must be within the following ranges during screening and on the day of dosing:
- body temperature, ≥35.5°C to ≤37.5°C
- systolic blood pressure, ≥90 to ≤150 mm Hg
- diastolic blood pressure, ≥50 to ≤95 mm Hg
- pulse rate, ≥40 to ≤100 bpm
- Non-vasectomized men must agree to use a condom with spermicide, double-barrier contraception, abstain from heterosexual intercourse, or have a sole-sexual partner of non childbearing potential during the trial and for 3 months after stopping the medication. Male subjects must agree not to donate sperm from the time of dosing until 90 days after dosing.
- Women of childbearing potential (defined as all women who are not surgically sterile or postmenopausal for at least 1 year prior to informed consent) must have a negative pregnancy test prior to enrolment and must agree to the following contraception requirements from screening through 3 months after dosing of the study drug:
- Be sexually inactive (abstinent)
- Intrauterine device in place for at least three months prior to dosing with a barrier method (condom or diaphragm) and spermicide throughout the study.
- Double barrier methods (e.g., condom and diaphragm) with spermicide for at least 14 days prior to dosing and throughout the study.
- Surgical sterilization of the partner (vasectomy at least six months prior to dosing) with a barrier method (e.g., condom or diaphragm) and spermicide throughout the study.
- Female subjects who claim to be sexually inactive but become sexually active during the course of the study must agree to use a double barrier method (e.g., condom and diaphragm) with spermicide from the time of the start of sexual activity through completion of the study. In addition, female subjects of childbearing potential must be advised to remain sexually inactive or to keep the same birth control method for at least 14 days following study medication administration. Females of non-childbearing potential must have undergone one of the following sterilization procedures at least 6 months prior to dosing:
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- Hysteroscopic sterilization and be using a barrier method (e.g., condom or diaphragm) and spermicide throughout the study.
- Bilateral tubal ligation or bilateral salpingectomy and be using a barrier method (e.g., condom or diaphragm) and spermicide throughout the study.
- Hysterectomy.
- Bilateral oophorectomy. Women with amenorrhea for at least 1 year prior to dosing and who have follicle-stimulating hormone (FSH) serum levels consistent with postmenopausal status, are considered post menopausal and therefore of non-childbearing potential.
- Subjects must be free of any clinically significant disease that would interfere with the study evaluations.
Who cannot join
- Ongoing treatment for a pre-existing chronic pain condition
- Use of an epidural / spinal block / major nerve block for the surgical procedure
- Surgical procedure that may interfere with the collection of data under the study protocol, such as craniofacial surgery which may impact the placement of a face mask for pulmonary function measurements.
- Current diagnosis of psychiatric disease, including anxiety disorder, that is uncontrolled and/or restricting normal daily function.
- History of alcohol abuse (more than an average of 2-drinks per day) within the past 2 years.
- History of drug abuse within the past 2 years.
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- History of regular smoking within the past year (\&gt;5 per week means exclusion).
- Positive for HIV, or Hepatitis B or C at screening.
- Blood donation or blood loss within 60 days of screening or plasma donation within 7 days of screening.
- Current or recent presentation of clinically significant of dyspnea, asthma, tuberculosis, chronic obstructive pulmonary disease, sleep apnea (central or obstructive) or any other ventilatory / lung disease.
- Treatment with another investigational drug within 3 months prior to screening or having participated in more than four investigational drug studies within 1 year prior to screening.
- History of moderate to severe motion sickness.
- Subjects who are unwilling to remove excessive facial hair preventing sealing of the occlusive face mask.
- Subjects who, in the opinion of the investigator, will not be able to participate optimally in the study.
- Any surgical or medical condition which might significantly alter the distribution, metabolism or excretion of any drug. The investigator should be guided by evidence of any of the following, and be discussed with the sponsor prior to enrollment into the trial:
- history of pancreatic injury or pancreatitis;
- history or presence of liver disease or liver injury;
- history or presence of impaired renal function as indicated by clinically significant elevation in creatinine, BUN/urea, urinary albumin, or clinically significant urinary cellular constituents; or
- history of urinary obstruction or difficulty in voiding.
- Subject who has a history of any infectious disease within 4 weeks prior to drug administration that in the opinion of the investigator, affects the subject's ability to participate in the trial.
- Subjects who are part of the study staff personnel or family members of the study staff personnel.
- Subjects who have demonstrated allergic reactions (e.g., food, drug, atopic reactions or asthmatic episodes) which, in the opinion of the investigator and sponsor, interfere with their ability to participate in the trial.
- Subjects who have a history of malignancy and are in remission \<5 years.
- Personal or family history of malignant hyperthermia.
- History of arrhythmias or ECG conductance abnormalities.
- Subjects with history of known difficult airway access and presence of a "non-reassuring" airway exam (as determined by the investigator), gastroesophageal reflex disease, gastric motility disorders, or delayed gastric emptying, or any condition that may lead to delayed gastric emptying such as diabetes.
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
Official title: A Placebo-controlled, Double-blind, Randomized Trial to Evaluate the Efficacy of ENA-001 in Preventing Postoperative Respiratory Depression
This study is a Phase II, randomized, placebo-controlled, double-blind trial in 200 subjects having general anesthesia for major elective surgery with postoperative pain management to evaluate the efficacy, safety and tolerability of ENA-001 as a therapy to prevent post operative respiratory depression.
- Conditions
- Respiratory Depression
- Being tested
- ENA-001
- Medical subject headings
- Respiratory Insufficiency
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
ENA-001Drug
ENA-001 will be prepared in Ringer's lactate solution. A loading dose will be administered for 20 minutes followed by continuous infusion until the patient meets the criteria for PACU discharge (≥ 9 Aldrete score) or ABG reveals PaCO2 < 30 mmHg with pH in the normal range. ENA-001 is for IV injection ready for use per subject by the investigational pharmacy, according to the randomization schedule.
| Study group | Role | What they receive |
|---|---|---|
| ENA-001 Treatment Arm | Experimental | ENA-001 consisting of continuous infusion of a loading dose of 2.0 mg/kg/hr for 20 minutes followed by a maintenance dose of 1.1 mg/kg/hr. Receives: Drug: ENA-001 |
| Placebo Treatment Arm | Placebo comparator | Matching placebo for ENA-001 will consist of the solution that is used as diluent for ENA-001. Placebo will be administered similarly consisting of continuous infusion of a loading dose of 2.0 mg/kg/hr for 20 minutes followed by a maintenance dose of 1.1 mg/kg/hr. Receives: Drug: ENA-001 |
What is being measured
The primary outcome is the main question the study is designed to answer.
To evaluate the effects of ENA-001 on pulmonary ventilation when administered to 100 subjects via continuous infusion of a loading dose of 2.0 mg/kg/hr for 20 minutes followed by a maintenance dose of 1.1 mg/kg/hr
To evaluate the effect of ENA-001 on pulmonary ventilation following extubation/airway removal up to two hours beyond cessation of treatment. Endpoint is arterial CO2 tension (PaCO2)
Measured: 2 hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Nov 2023
- Study start15 Dec 2026 (estimated)
- Primary completion15 Jun 2027 (estimated)
- Study completion15 Jul 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Respiratory DepressionStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 200 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Enalare Therapeutics Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06137638
- Sponsor's protocol ID
- ENA-001-201
- Status last verified
- Feb 2026
- First submitted
- 14 Nov 2023
- Last updated
- 27 Feb 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 27 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Placebo-controlled, Double-blind, Randomized Trial to Evaluate the Efficacy of ENA-001 in Preventing Postoperative Respiratory Depression
- ClinicalTrials.gov ID
- NCT06137638
- Acronym / sponsor ID
- ENA-001-201
- Conditions
- Respiratory Depression
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 200 participants (estimated)
- Lead sponsor
- Enalare Therapeutics Inc.Industry (pharma, biotech, devices)
- Study start
- 15 Dec 2026 (estimated)
- Primary completion
- 15 Jun 2027 (estimated)
- Study completion
- 15 Jul 2027 (estimated)
- First posted
- 18 Nov 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study is a Phase II, randomized, placebo-controlled, double-blind trial in 200 subjects having general anesthesia for major elective surgery with postoperative pain management to evaluate the efficacy, safety and tolerability of ENA-001 as a therapy to prevent post operative respiratory depression.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| ENA-001 Treatment Arm | Experimental | Drug: ENA-001ENA-001 consisting of continuous infusion of a loading dose of 2.0 mg/kg/hr for 20 minutes followed by a maintenance dose of 1.1 mg/kg/hr. |
| Placebo Treatment Arm | Placebo comparator | Drug: ENA-001Matching placebo for ENA-001 will consist of the solution that is used as diluent for ENA-001. Placebo will be administered similarly consisting of continuous infusion of a loading dose of 2.0 mg/kg/hr for 20 minutes followed by a maintenance dose of 1.1 mg/kg/hr. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (25 listed)
- Willing to give written informed consent for the trial and willing/able to adhere to study procedures.
- Scheduled to undergo a major elective surgery, including abdominal, laparoscopic, nephrology, thoracic (non-cardiac), orthopedic (e.g., shoulder and ankle surgery), where the subject will be transferred to recover in the general postanesthesia recover unit (PACU) and extubation will be performed in the operating room or PACU.
- Undergoing surgical procedure with a intraoperative requirement of ≥ 250 µg of fentanyl; Enrolled base on expected pain management to necessitate ≥ 250 µg of fentanyl intraoperatively.
- Male and female, ≥18 years of age.
- American Society of Anesthesiologists (ASA) physical status classification 1-3.
Key exclusion criteria (26 listed)
- Ongoing treatment for a pre-existing chronic pain condition
- Use of an epidural / spinal block / major nerve block for the surgical procedure
- Surgical procedure that may interfere with the collection of data under the study protocol, such as craniofacial surgery which may impact the placement of a face mask for pulmonary function measurements.
- Current diagnosis of psychiatric disease, including anxiety disorder, that is uncontrolled and/or restricting normal daily function.
- History of alcohol abuse (more than an average of 2-drinks per day) within the past 2 years.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| ENA-001ENA-001 will be prepared in Ringer's lactate solution. A loading dose will be administered for 20 minutes followed by continuous infusion until the patient meets the criteria for PACU discharge (≥ 9 Aldrete score) or ABG reveals PaCO2 < 30 mmHg with pH in the normal range. ENA-001 is for IV injection ready for use per subject by the investigational pharmacy, according to the randomization schedule. | Drug | ENA-001 Treatment Arm, Placebo Treatment Arm |
Primary outcome
To evaluate the effects of ENA-001 on pulmonary ventilation when administered to 100 subjects via continuous infusion of a loading dose of 2.0 mg/kg/hr for 20 minutes followed by a maintenance dose of 1.1 mg/kg/hr
Time frame: 2 hours
To evaluate the effect of ENA-001 on pulmonary ventilation following extubation/airway removal up to two hours beyond cessation of treatment. Endpoint is arterial CO2 tension (PaCO2)
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 27 Feb 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing ENA-001 in people with Respiratory Depression, run by Enalare Therapeutics Inc..
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 25 inclusion and 26 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 27 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Mathews (9089475491, jmathews@enalare.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
To evaluate the effects of ENA-001 on pulmonary ventilation when administered to 100 subjects via continuous infusion of a loading dose of 2.0 mg/kg/hr for 20 minutes followed by a maintenance dose of 1.1 mg/kg/hr (time frame: 2 hours). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 27 Feb 2026; AzTrials last refreshed its copy on 6 Nov 2026.