A single-center, open-label, single-arm trial to evaluate the efficacy and safety of cidofovir IV therapy combined with oral probenecid for patients with mpox or smallpox.

JRCT ID: jRCTs031230652

Registered date:22/02/2024

Basic Information

• Recruitment status: Recruiting
• Health condition(s) or Problem(s) studied: Mpox or Smallpox
• Date of first enrollment: 22/02/2024
• Target sample size: 20
• Study type: Interventional
• Intervention(s): In this study, cidofovir will be administered in com bination with probenecid.

Outcome(s)

• Primary Outcome: Percentage of patients with a Ct value of 40 or higher on PCR testing of skin samples at the site of the rash 14 days after study entry.

Secondary Outcome

-Mortality at 14 and 30 days post enrollment
-Virus levels in blood, throat swabs, skin, and urine at 14, 21, 30, 60, and 120 days after enrollment
-Duration of fever 37.5 degrees or higher after study entry
-Adverse events since study entry
-General condition (bedridden, briefly bedridden, or completely bedridden) at baseline, 14 days, and 30 days after baseline

Key inclusion & exclusion criteria

• Age minimum: >= 18age old
• Age maximum: < 60age old
• Gender: Both

Include criteria

In case of smallpox, the patient must satisfy 1) to 3) and 6). In the case of Mpox, all of 1) to 6) must be met.
1) Individuals who have given written consent to participate in research.
2) Persons who are between the ages of 18 and 60 at the time of consent.
3) Individuals who have been diagnosed with mpox or smallpox. However, smallpox is diagnosed when the agent is detected in a blister, pustule, crust, throat swab, or blood sample, and mpox is diagnosed when the agent is detected in a skin or mucosal lesion, blister contents, nasopharyngeal swab, or blood sample, nasopharyngeal swab, pharyngeal swab, anorectal swab, other mucosal swab, blood, urine, or other material appropriate to the test method, by any of the following methods.
Direct observation of viral particles by electron microscopy
Detection of pathogens by isolation and identification
Detection of pathogen antigens by the fluorescent antibody method
Detection of pathogen genes by PCR
4) Persons participating in the Multicenter, Open Label, Two Arm, Multicenter Study to Evaluate the Efficacy and Safety of Oral Tecovirimat Treatment for mpox and Smallpox (hereafter referred to as the Tecopox Study) Certification No CRB3200011 and who are treated with tecovirimat.
5) Patients with severe mpox or severe high risk mpox.
6) Patients who agree to be hospitalized and treated with cidofovir for up to 30 days after initiation of treatment with cidofovir.

Exclude criteria

1) Patients with renal insufficiency (serum creatinine level > 1.5 mg/dl, creatinine clearance <= 55 ml/min), proteinuria (urine protein = > 100 mg/dl, urine protein qualitative = > 2+).
(2) Patients who are receiving or have received within 7 days drugs with potential nephrotoxicity (drugs with potential nephrotoxicity: aminoglycoside injection (tobramycin, gentamicin, amikacin, etc.), amphotericin B, foscarnet, pentamidine injection, vancomycin, non-steroidal anti-inflammatory drugs, etc.).
3) Patients who are receiving or have received brincidofovir within 7 days.
4) Patients with a history of hypersensitivity to cidofovir
5) Patients who have had hypersensitivity reactions to probenecid.
6) Patients with allergy to sulfa drugs
7) Patients with kidney stone disease
8) Patients with blood disorders
9) Pregnant women
10) Nursing patients
11) Patients deemed inappropriate for inclusion in the study by the investigator

Related Information

• Primary Sponsor: Morioka Shinichiro
• Secondary Sponsor: Ohmagari Norio,Japan Agency for Medical Research and Development