By Deena Beasley

(Reuters) – Laboratory (NYSE:) studies show that Merck & Co’s experimental oral COVID-19 antiviral drug, molnupiravir, is likely to be effective against known variants of the coronavirus, including the dominant, highly transmissible Delta, the company said on Wednesday.

Jay Grobler from Merck, who heads infectious disease and vaccines said that Molnupiravir is not designed to target the spike protein.

Molnupiravir, instead, targets viral polymerase. It is an enzyme that allows the virus to create copies of itself. The drug is intended to introduce errors in the virus’ genetic code.

Merck stated that data shows the drug’s effectiveness is greatest when administered early in the infection process.

U.S. pharmaceutical company Merck tested the antiviral against nasal samples obtained from patients in its early trials. Although Delta wasn’t in widespread circulation during those trials, molnupiravir (molnapiravir) was tested against laboratory samples from the COVID-19 variant that caused the recent surge in deaths and hospitalizations.

Merck will conduct two Phase III studies of an antiviral in partnership with Ridgeback Biotherapeutics. The first is for COVID-19 treatment, the second is preventive.

Grobler stated that Merck expects to complete the first study in November. Grobler said that data could be available sooner or later.

IDWeek is the annual meeting for infectious disease organizations including the Infectious diseases Society of America. The researchers presented their findings at the conference.