Pfizer CEO Albert Bourla expressed confidence Wednesday about the results of the data behind the manufacturer’s COVID-19 anti-viral pill before it is submitted to U.S regulators. 

On Tuesday, Bourla announced that in the coming day Pfizer would be submitting its full data on the pill, called Paxlovid, to the Food and Drug Administration. He touted the results of clinical trials that show an 89% reduction of hospitalizations and deaths in patients.

“I feel comfortable the data that we will submit will mimic at large what we saw in the first part of the study. When we unblind the data I don’t expect we will have a difference," said Bourla in an interview with CNBC on Wednesday.

Since Pfizer first announced its anti-viral pill, it has been emphasizing the value of its new product in the fight against COVID-19. Pfizer has struck agreements to supply 10 million pills to the U.S government and a global licensing deal to provide supplies to lower-income nations. 

Pfizer’s submission to the FDA also arrives at a time when concern is mounting about the new Omicron variant that emerged from South Africa. Bourla has said that the early data on Omicron does not suggest that it can impact the efficacy of its pill and that Pfizer would be working to retool its vaccine to fight the new strain. 

An approval for Pfizer’s pill would make it the second COVID anti-viral pill to receive the FDA’s go-ahead. On Nov. 30, the agency greenlighted the use of Merck’s pill by granting it an emergency use authorization for use, despite some concern about its effectiveness.