Phase 2 Trial to Evaluate Safety and Efficacy of CYTO-205 in Mild COVID-19


This is a randomized, double-blind, placebo-controlled study. The aim of the study is to assess the safety and clinical efficacy of low-dose naltrexone in reducing the proportion of higher risk patients who progress from mild COVID-19 to a more severe disease category. Male and female participants with a confirmed positive SARS-CoV-2 diagnostic test at screening, who are symptomatic with mild COVID-19 (as measured by WHO clinical progression scale, WHOb 2020) and are at high risk for COVID-19 progression will be enrolled. High risk is based on presence of one or more criteria which could include age ≥65 years, increased BMI ≥33 kg/m2, or the presence of certain comorbidities (refer to Section 4 for complete eligibility criteria).

Full Title of Study: “A Randomized, Placebo-controlled, Phase 2 Study to Evaluate Safety and Efficacy of CYTO-205 (Low-dose Naltrexone) in Adult Patients With Mild COVID-19 Infection Who Are at High Risk for Disease Progression”

Study Type

  • Study Type: Interventional
  • Study Design
    • Allocation: Randomized
    • Intervention Model: Parallel Assignment
    • Primary Purpose: Treatment
    • Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
  • Study Primary Completion Date: April 2022


  • Drug: Naltrexone Hydrochloride
    • naltrexone hydrochloride capsules 4.5 mg each

Arms, Groups and Cohorts

  • Placebo Comparator: Placebo
  • Experimental: CYTO-205 22.5 mg
  • Experimental: CYTO-205 45 mg

Clinical Trial Outcome Measures

Primary Measures

  • Proportion of patients who demonstrate progression of COVID-19 disease
    • Time Frame: Day 1 to Day 30
    • Progression of COVID-19 disease based on the WHO clinical progression scale (WHOb2020)

Participating in This Clinical Trial

Inclusion Criteria

1. Age >18 at the time of informed consent 2. Able to understand and provide informed consent in either English or Spanish 3. At high risk for COVID-19 disease progression by fulfilling at least ONE of the following criteria at Screening: 1. Age ≥65 years 2. Has a diagnosis of chronic pulmonary disease requiring daily treatment (e.g. COPD, chronic persistent asthma, cystic fibrosis, chronic bronchitis) 3. Has a diagnosis of chronic heart disease 4. Has a diagnosis of diabetes (type 1 or type 2) requiring oral therapy and/or insulin therapy 5. Has hypertension requiring at least one oral medication for treatment 6. Has a body mass index (BMI) of ≥33 kg/m2 7. Has an immunocompromising disease (e.g. HIV infection with CD4 count < 200 cells/mm3) 8. Is immunocompromised due to daily treatment with ≥20 mg of prednisone or equivalent 9. Has received a solid organ transplant 10. Has any chronic condition that, in the opinion of the investigator, places the patient at increased risk for progression of COVID-19 4. Documentation of positive diagnostic test for SARS-CoV-2 (confirmed by PCR assay or other approved diagnostic test) performed with a sample from nares or saliva, collected within 7 days of the Screening visit. 5. Is symptomatic for COVID-19 for no more than 7 days prior to the Screening visit 6. Has a WHO Clinical Progression Scale (WHOb 2020) score of either '2' or '3' at Screening and Randomization 7. Has at least one of the following symptoms at the Screening visit that are new in onset, or if present by history, has worsened during the 7 days prior to Screening: · fever, chills, myalgia, arthralgia, headache, fatigue, cough, sore throat, nasal congestion, nausea, vomiting, diarrhea, anosmia or dysosmia, ageusia or dysgeusia 8. If female of child-bearing potential, must agree to use of 2 forms of contraception from Screening to end of the study. Males must agree to use 2 forms of contraception from screening to the end of the study if their partners are of childbearing potential. Acceptable methods of birth control which must be used together are: 1. Oral or injectable contraceptive and condom, or 2. IUD and condom, or 3. Diaphragm with spermicide and condom. 9. Agrees to participate in all in-person visits and remote or home visits as required by the protocol and to provide updated contact information, as necessary. Exclusion Criteria:

1. Has a WHO Clinical Progression Scale (WHOb 2020) score of '4' or higher at Screening or Enrollment 2. Previous hypersensitivity or allergic reactions to naltrexone 3. Women who are pregnant or lactating or expecting to become pregnant 4. Drugs of abuse screen positive for opiates 5. Patients with history of moderate to severe renal impairment (estimated creatinine clearance < 50 mL/min) or hepatic impairment (Child-Pugh C) 6. Serum ALT or AST value > 3 times the ULN at Screening 7. Serum creatinine value > 2 times the ULN at Screening, or requires renal dialysis 8. Hematology results at Screening showing any one of the following: WBC <2000 cells/mm3 or platelet count <100,000 cells/mm3 or hemoglobin <8.5 Gm/dL 9. Currently receiving chronic daily opioid therapy 10. Use of tocilizumab or other immunomodulator therapy directed to treatment or prevention of COVID-19 11. History of active substance abuse within the 2 years prior to Screening 12. Participation in another clinical trial investigating a treatment for COVID-19 13. Currently hospitalized or under immediate consideration for hospitalization (for any medical reason) at the Screening visit 14. At Screening, has new onset of dyspnea (shortness of breath) or, if previously diagnosed with a chronic lung condition, the severity of dyspnea has increased over patient's historical baseline condition (increased dyspnea should be present continually and not intermittent) 15. Measurement of oxygen saturation at Screening is < 94% on ambient room air 16. Shares a household with a patient currently enrolled in this protocol 17. Patients who refuse biomarker blood draws

Gender Eligibility: All

Minimum Age: 18 Years

Maximum Age: N/A

Are Healthy Volunteers Accepted: No

Investigator Details

  • Lead Sponsor
    • Cytocom, Inc.
  • Provider of Information About this Clinical Study
    • Sponsor

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