Mpox Treatment Effectiveness Varies

The National Institute of Allergy and Infectious Diseases (NIAID) of the National Institutes of Health announced topline results from a preliminary PALM 007 phase 2 clinical trial analysis.

The NIAID reported on August 15, 2024, that the study did not meet its primary endpoint of a statistically significant improvement in time to lesion resolution within 28 days post-randomization for patients with mpox who were administered SIGA’s oral tecovirimat (TPOXX®) a highly targeted antiviral treatment, versus placebo.

However, a meaningful improvement was observed in patients receiving tecovirimat whose symptoms began seven days or fewer before randomization and those with severe or more significant disease.

This study's finding is essential given Africa's ongoing clade 1 mpox virus outbreak.

“These data showing maximum benefit in patients treated early and with severe disease are entirely consistent with the mechanism of action of tecovirimat and with the studies in animals that led to U.S. FDA approval of this medicine for smallpox..... We believe these data warrant further investigation and support our view that post-exposure prophylaxis will be vital for the treatment of severe cases of mpox and all cases of smallpox,” stated Dennis Hruby, Chief Scientific Officer, in a press release.

On July 22, 2024, the U.S. government exercised a procurement option to deliver approximately $113 million in TPOXX treatment courses. 

TPOXX is currently available in the U.S., United Kingdom, Canada, and Europe.