Update on managing monkeypox (mpox) in patients receiving therapeutics

Actions requested

• Be aware that the Centers for Disease Control and Prevention (CDC) has confirmed the presence of tecovirimat-resistant monkeypox (mpox) in two patients.
  • Note that no transmission of tecovirimat-resistant mpox virus has been documented so far.
  • Vaccination with JYNNEOS remains an important tool to prevent mpox in at-risk patients.
• Continue to consider tecovirimat (also known as TPOXX or ST-246) as first-line therapy for eligible patients with mpox.
  
  • Recognize that patients who either have or are at high risk for severe disease may require longer courses (>14 days) of tecovirimat, and additional therapies, until their immune systems can effectively clear the virus.
    
    • These include patients who have HIV with CD4 counts <350 cells/mm3 and patients with other severely immunocompromising conditions.
    • Additional therapeutics include cidofovir (intravenous), brincidofovir (oral), and Vaccinia Immune Globulin Intravenous (VIGIV).
  • Counsel patients about the critical importance of taking oral tecovirimat with fatty meals to ensure adequate gastrointestinal absorption and maximize serum levels of the medication. Inadequate serum levels could promote resistance.
• Consider testing lesion swab specimens for tecovirimat resistance and plasma pharmacokinetic sample collection for any patient who, after completing 14 days of tecovirimat treatment, experiences persistent or newly emergent mpox lesions.
  
  • Perform resistance testing and pharmacokinetic testing to determine if any cases of confirmed resistance are associated with drug levels below target concentrations.
  • CDC provides detailed instructions for collecting and submitting specimens for resistance testing and pharmacokinetic testing. Pharmacokinetic testing is not performed at CDC.
  • Report possible tecovirimat resistant mpox cases to Public Health at the time of suspicion and/or testing (206-296-4774).
• Providers prescribing tecovirimat, consider first seeking access through enrollment in the AIDS Clinical Trials Group (ACTG) Study of Tecovirimat for Human Mpox Virus (STOMP) trial, which is evaluating the efficacy of tecovirimat.
  
  • For patients not eligible for the STOMP trial or who decline to participate, contact Public Health – Seattle & King County using this request form to receive information regarding CDC’s Tecovirimat Expanded Access-IND.