• For patients treated under the EA-IND protocol and included in this report, the median time to subjective improvement was 3 days after receiving tecovirimat. However, no control group was available for comparison; therefore, no conclusions can be drawn regarding the effectiveness of tecovirimat to treat monkeypox based on these data.
 
• Interim CDC guidance currently recommends that tecovirimat be considered in patients with severe disease, those at high risk for severe disease, or those with aberrant infections. This report describes the available demographic and clinical characteristics, clinical indications for use, clinical outcomes, and adverse events reported among some of the first known recipients of tecovirimat treatment under the EA-IND protocol for Monkeypox virus infection in the United States.
 
• Ongoing monitoring is essential to assess the safety of tecovirimat in patients with Monkeypox virus infection under the EA-IND during the current monkeypox outbreak. CDC is continuing to review additional data as they become available. Currently, there are no human data demonstrating the efficacy of tecovirimat, and clinical trials are necessary to elucidate clinical efficacy in patients with Monkeypox virus infection, indications for treatment, and ideal duration of treatment.
 
• Approximately one half of patients with Monkeypox virus infection who received tecovirimat were living with HIV infection.
 
• the oral formulation of tecovirimat was prescribed to 494 (99.8%) at the start of therapy. Median interval from symptom onset to receipt of first tecovirimat dose was 7 days (IQR = 5-10 days) (Figure).
 
• CDC abstracted data from patient intake forms for 549 persons with confirmed or suspected monkeypox who were prescribed tecovirimat therapy by August 20, 2022, and outcome forms for 369 patients.
 
• Among 464 patients with race and ethnicity data, 180 (38.8%) were White persons, 161 (34.7%) were Hispanic or Latino persons, and 83 (17.9%) were non-Hispanic Black or African American persons.
 
• Among 317 patients with available outcome information, 230 (72.6%) recovered with or without sequelae
 
• For patients treated under the EA-IND protocol and included in this report, the median time to subjective improvement was 3 days after receiving tecovirimat.
 
• Among 529 patients with available data on number of lesions, 299 (56.5%) reported 10-100 lesions at the start of tecovirimat; 210 (39.7%) had fewer than 10 lesions, and 20 (3.8%) had more than 100 lesions. The presence of lesions in anatomic areas that might result in serious sequelae was reported on 191 (79.6%) of the 240 revised intake forms with available data. The most frequently reported underlying medical condition affecting immune status was HIV infection (254, 46.3%); viral load and CD4 count were not reported.
 
• Among 495 persons with available data on route of administration, the oral formulation of tecovirimat was prescribed to 494 (99.8%) at the start of therapy. Median interval from symptom onset to receipt of first tecovirimat dose was 7 days (IQR = 5-10 days) (Figure). Among 260 persons with revised intake forms, 124 (47.7%) had laboratory-confirmed Orthopoxvirus infection when tecovirimat treatment commenced.
 
• Among 369 patients with outcome forms, data on hospitalization status was available for 331; among these, 23 (6.9%) were hospitalized after symptom onset (Table 2), and the median duration of hospitalization was 4 days (IQR = 1-5 days). Among 255 patients with available data, the median time to subjective improvement after starting treatment was 3 days (IQR = 2-4 days). Among 317 patients with available outcome information, 230 (72.6%) recovered with or without sequelae**** by or before completion of the posttreatment assessment; 87 (27.4%) patients were reported by clinicians to be not yet recovered, 78 of whom had not yet completed the standard 14-day tecovirimat treatment course. Adverse events were reported for 12 (3.5%) of 340 patients with information on adverse events; these included headache (three), nausea (two), visual disturbance (two), weakness (two), and hospitalization for psychiatric reasons (one).
 
• At the time of the posttreatment follow-up visit, three (2.2%) of 137 persons with information available had developed new lesions compared with 25 (13.1%) who had developed new lesions during the first week of treatment. Most (119, 89.5%) patients reported that all lesions were crusted and healing with a new layer of skin under the scab following treatment. Among 174 patients with available data, the interval to subjective improvement did not differ between HIV-positive persons (42; median = 3 days) and persons without documentation of HIV positive status (64; median = 3 days) with available data (p = 0.83).