Treatment
MPXV usually causes mild symptoms and most patients recover without
treatment. However, in severe cases of MPX, supportive care, symptom
management, and treatment of secondary bacterial infections remain the
main recommendations [57]. No effective antiviral therapy has been
identified yet, however, some antiviral drugs for Smallpox can also be
used for MPX [7]. Tecovirimat (ST-246) was first proposed as an
antiviral candidate for the treatment of orthopoxvirus infections in
2005 [67]. Studies have proven that treatment with Tecovirimat is
effective in animal models and human cases, with a significant reduction
in mortality [68,69]. Tecovirimat has been approved by the FDA for
use in the treatment of MPX during outbreaks [70]. F13/VP37, the
viral structural protein of MPXV, plays an essential role in the
formation of cell-associated enveloped viruses prior to viral release.
Tecovirimat inhibits the spread of the virus within the infected host by
inhibiting F13/VP37 [71]. Some studies have now demonstrated the
potential of drugs targeting inhibition of the MPXV-F13 protein for the
successful treatment of MPXV, although additional in vitro and in vivo
experiments are still necessary [72,73]. Cidofovir is a
broad-spectrum antiviral drug effective against almost all DNA viruses,
and its anti-MPXV activity in vivo has been demonstrated in different
monkey infection models [74]. However, cidofovir is only effective
in preventing death if given before the onset of the rash [75].
Because cidofovir causes significant nephrotoxicity and has limited
efficacy data in human MPX, the use of this drug is likely to remain
limited to the treatment of severe cases [27]. CMX001 and
Brincindofovir, as cidofovir derivatives, block orthopoxvirus DNA
polymerase-mediated viral DNA synthesis. These drugs have a better renal
safety profile compared to cidofovir. A UK report found that seven
patients recovered completely from MPX infection after treatment with
Brincindofovir, although three of them developed elevated alanine
transaminases [58]. Vaccinia Immune Globulin Intravenous can be used
to treat MPX during outbreaks and complications due to vaccinia
vaccination [7].