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. 2023 Mar 14;3(3):CD015769.
doi: 10.1002/14651858.CD015769.

Therapeutics for treating mpox in humans

Tilly Fox  1 , Susan Gould  2 , Naveena Princy  3 , Tim Rowland  1 , Vittoria Lutje  1 , Rebecca Kuehn  1
Affiliations

Therapeutics for treating mpox in humans

Tilly Fox et al. Cochrane Database Syst Rev. .

Abstract

Background: Mpox was declared a Public Health Emergency of International Concern (PHEIC) by the World Health Organization (WHO) on 23 July 2022, following the identification of thousands of cases in several non-endemic countries in previous months. There are currently no licenced therapeutics for treating mpox; however, some medications may be authorized for use in an outbreak. The efficacy and safety of possible therapeutic options has not been studied in humans with mpox. There is a need to investigate the evidence on safety and effectiveness of treatments for mpox in humans; should any therapeutic option be efficacious and safe, it may be approved for use around the world.

Objectives: There are two parts to this Cochrane Review: a review of evidence from randomized controlled trials (RCTs), and a narrative review of safety data from non-randomized studies. Randomized controlled trials review To systematically review the existing evidence on the effectiveness of therapeutics for mpox infection in humans compared to: a) another different therapeutic for mpox, or b) placebo, or c) supportive care, defined as the treatment of physical and psychological symptoms arising from the disease. Non-randomized studies review To assess the safety of therapeutics for mpox infection from non-randomized studies (NRS).

Search methods: Randomized controlled trials review We searched the following databases up to 25 January 2023: MEDLINE (OVID), Embase (OVID), Biosis previews (Web of Science), CAB Abstracts (Web of science), and Cochrane CENTRAL (Issue 1 2023). We conducted a search of trial registries (Clinicaltrials.gov and International Clinical Trials Registry Platform (ICTRP)) on 25 January 2023. There were no date or language limits placed on the search. We undertook a call to experts in the field for relevant studies or ongoing trials to be considered for inclusion in the review. Non-randomized studies review We searched the following databases on 22 September 2022: Cochrane Central Register of Controlled Trials (CENTRAL; Issue 9 of 12, 2022), published in the Cochrane Library; MEDLINE (Ovid); Embase (Ovid); and Scopus (Elsevier). We also searched the WHO International Clinical Trials Registry Platform and ClinicalTrials.gov for trials in progress.

Selection criteria: For the RCT review and the narrative review, any therapeutic for the treatment of mpox in humans was eligible for inclusion, including tecovirimat, brincidofovir, cidofovir, NIOCH-14, immunomodulators, and vaccine immune globulin. Randomized controlled trials review Studies were eligible for the main review if they were of randomized controlled design and investigated the effectiveness or safety of therapeutics in human mpox infection. Non-randomized studies review Studies were eligible for inclusion in the review of non-randomized studies if they were of non-randomized design and contained data concerning the safety of any therapeutic in human mpox infection.

Data collection and analysis: Randomized controlled trials review Two review authors independently applied study inclusion criteria to identify eligible studies. If we had identified any eligible studies, we planned to assess the risk of bias, and report results with 95% confidence intervals (CI). The critical outcomes were serious adverse events, development of disease-related complications, admission to hospital for non-hospitalized participants, pain as judged by any visual or numerical pain scale, level of virus detected in clinical samples, time to healing of all skin lesions, and mortality. We planned to perform subgroup analysis to explore whether the effect of the therapeutic on the planned outcomes was modified by disease severity and days from symptom onset to therapeutic administration. We also intended to explore the following subgroups of absolute effects: immunosuppression, age, and pre-existing skin disease. Non-randomized studies review One review author applied study inclusion criteria to identify eligible studies and extracted data. Studies of a non-randomized design containing data on the safety of therapeutics could not be meta-analyzed due to the absence of a comparator; we summarized these data narratively in an appendix.

Main results: Randomized controlled trials review We did not identify any completed RCTs investigating the effectiveness of therapeutics for treating mpox for the main review. We identified five ongoing trials that plan to assess the effectiveness of one therapeutic option, tecovirimat, for treating mpox in adults and children. One of these ongoing trials intends to include populations with, or at greater risk of, severe disease, which will allow an assessment of safety in more vulnerable populations. Non-randomized studies review Three non-randomized studies met the inclusion criteria for the narrative review, concerning data on the safety of therapeutics in mpox. Very low-certainty evidence from non-randomized studies of small numbers of people indicates no serious safety signals emerging for the use of tecovirimat in people with mpox infection, but a possible safety signal for brincidofovir. All three participants who received brincidofovir had raised alanine aminotransferase (ALT), but not bilirubin, suggesting mild liver injury. No study reported severe drug-induced liver injury with brincidofovir.

Authors' conclusions: Randomized controlled trials review This review found no evidence from randomized controlled trials concerning the efficacy and safety of therapeutics in humans with mpox. Non-randomized studies review Very low-certainty evidence from non-randomized studies indicates no serious safety signals emerging for the use of tecovirimat in people with mpox infection. In contrast, very low-certainty evidence raises a safety signal that brincidofovir may cause liver injury. This is also suggested by indirect evidence from brincidofovir use in smallpox. This warrants further investigation and monitoring. This Cochrane Review will be updated as new evidence becomes available to assist policymakers, health professionals, and consumers in making appropriate decisions for the treatment of mpox.

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Conflict of interest statement

TF is a Cochrane Infectious Diseases Group (CIDG) Research Associate, and was not involved in the editorial process. She has no known conflicts of interest to declare.

SG is a co‐author on one included study in this review. SG was not involved in any inclusion decisions, data extraction, or risk of bias assessment for this study.

NP has no known conflicts of interest to declare.

TR has no known conflicts of interest to declare.

VL is the CIDG Information Specialist, and was not involved in the editorial process. She has no known conflicts of interest to declare.

RK is a CIDG Research Associate, and was not involved in the editorial process. She has no known conflicts of interest to declare.

Figures

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Alanine transaminase values of the three participants who received therapy with brincidofovir (reproduced with permission from Adler 2022)
See this image and copyright information in PMC

References

References to studies excluded from this review

ISRCTN43307947 {published data only}
    1. ISRCTN43307947. Expanded access protocol for the use of tecovirimat for the treatment of monkeypox infection. www.isrctn.com/ISRCTN43307947 (first received 4 June 2021).
jRCTs031220169 {published data only}
    1. jRCTs031220169. A multicenter, open-label, double-arm trial to evaluate the efficacy and safety of oral tecovirimat therapy for patients with smallpox or monkeypox. rctportal.niph.go.jp/en/detail?trial_id=jRCTs031220169 (first received 28 June 2022).

References to ongoing studies

ISRCTN17461766 {published data only}
    1. ISRCTN17461766. Antiviral treatment with tecovirimat for patients managed at home with monkeypox (PLATINUM) [Placebo-controlled randomised trial of tecovirimat in non-hospitalised monkeypox patients (PLATINUM)]. isrctn.com/ISRCTN17461766 (first received 17 August 2022).
NCT05534165 {published data only}
    1. NCT05534165. Tecovirimat in non-hospitalized patients with monkeypox (PLATINUM-CAN) [Placebo-controlled randomized trial of tecovirimat in non-hospitalized patients with monkeypox: Canadian feasibility study (PLATINUM-CAN)]. clinicaltrials.gov/ct2/show/NCT05534165 (first received 9 September 2022).
NCT05534984 {published data only}
    1. NCT05534984. Study of tecovirimat for human monkeypox virus (STOMP) [A randomized, placebo-controlled, double-blinded trial of the safety and efficacy of tecovirimat for the treatment of human monkeypox virus disease]. clinicaltrials.gov/ct2/show/NCT05534984 (first received 10 September 2022).
NCT05559099 {published data only}
    1. NCT05559099. Tecovirimat for treatment of monkeypox virus (PALM 007) [A randomized, placebo-controlled, double-blinded trial of the safety and efficacy of tecovirimat for the treatment of adult and pediatric patients with monkeypox virus disease]. clinicaltrials.gov/ct2/show/NCT05559099 (first received 29 September 2022).
NCT05597735 {published data only}
    1. NCT05597735. Assessment of the efficacy and safety of tecovirimat in patients with monkeypox virus disease (UNITY) [A Phase III, multi-country, randomized, placebo-controlled, double-blinded trial to assess the efficacy and safety of tecovirimat antiviral treatment for patients with monkeypox virus disease]. clinicaltrials.gov/ct2/show/NCT05597735 (first received 28 October 2022).

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References to other published versions of this review

Fox 2022
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