Pfizer Doses Its First Patient in Phase 2/3 Trial for Daily COVID-19 Pill

Health worker prepares a dose of a vaccine in the Israeli town of Rishon Lezion, on Aug. 13, 2021. Ahmad Gharabli/AFP via Getty Images

Pfizer revealed on Wednesday that it gave its first dose to a patient participating in its phase 2/3 clinical trial examining the efficacy of an orally administered drug that is designed to combat COVID-19.

CEO Albert Bourla on Wednesday night wrote on Twitter that “success against COVID19 will likely require both vaccines [and] treatments” and said the pharmaceutical giant started a “Phase 2/3 study of our oral antiviral candidate—specifically designed to combat SARS-CoV-2—in non-hospitalized, low-risk adults.”

The drug, which has been dubbed PF-07321332, is designed for COVID-19 patients who haven’t been hospitalized but who have symptoms of the virus and are at low risk of seeing it progress to become a severe disease.

The randomized, double-blind trial will enroll about 1,140 participants, who will get either PF-07321332 or a placebo orally every 12 hours for five days, according to a press release from Pfizer (pdf).

“Protease inhibitors, like PF-07321332, are designed to block the activity of the main protease enzyme that the coronavirus needs to replicate,” the release said. “Co-administration with a low dose of ritonavir is expected to help slow the metabolism, or breakdown, of PF-07321332 in order for it to remain in the body for longer periods of time at higher concentrations, thereby working continuously to help combat the virus.”

Currently, the only three COVID-19 drugs approved by the Food and Drug Administration (FDA) are the vaccines made by Pfizer, Moderna, and Johnson & Johnson.

Earlier this week, the U.S. Centers for Disease Control and Prevention said that the vaccines’ efficacy for keeping people out of the hospital has dropped. In an update, the agency said that against the Delta variant, the vaccines’ effectiveness at keeping people out of the hospital was between 75 percent and 95 percent in July—a drop from 97 percent in June.

It comes as the American Medical Association (AMA) called for “immediate end” to the use of ivermectin to treat COVID-19, and for doctors to stop prescribing it after podcast host and comedian Joe Rogan confirmed he took the drug in combination with other medications to treat COVID-19.

“We are alarmed by reports that outpatient prescribing for and dispensing of ivermectin have increased 24-fold since before the pandemic and increased exponentially over the past few months,” the AMA said on Thursday.

Ivermectin has been labeled as a “horse dewormer” by some mainstream media outlets, but the drug has been used for decades to treat river blindness and intestinal roundworm infection in humans. Over the course of the pandemic, some doctors have prescribed it for COVID-19, and several Indian states authorized the drug’s usage to treat the virus earlier this year.

Variations of the drug are given to pets and livestock, and federal officials have warned people against taking animal ivermectin for COVID-19, saying it could lead to hospitalization or even death. In veterinary medicine, the drug is designed to prevent and treat heartworm.

COVID-19 is the illness caused by the CCP (Chinese Communist Party) virus.