Pfizer soars 11% on strong results from COVID-19 pill study, while Moderna and Merck tumble

• Pfizer stock soared as much as 11% on Friday after the drugmaker said its COVID-19 pill cuts risk of severe COVID-19 by 89%.

• Merck stock tumbled as results reported last month from its rival COVID-19 pill were surpassed by Pfizer's.

Pfizer stock soared as much as 11% Friday after the drug giant said its COVID-19 pill cuts the risk of severe COVID-19 by 89%.

The strong evidence of the antiviral pill decreasing chances of hospitalization or death for high-risk adults prompted Pfizer to stop the drug trial. The company plans to seek the Food and Drug Administration's OK this month for the pill, with doses potentially ready for delivery this year.

Rival Merck, which is also producing a COVID-19 pill, saw shares fall as much as 10% on Friday. Merck said last month that trial results for it's COVID-19 pill, molnupiravir, showed it halved the risk of hospitalization or death for COVID-19 patients.

Shares of Moderna, which developed a COVID-19 vaccine, tumbled 22% at intraday lows as investors anticipate lower demand for shots. The selloff comes on the heels of Moderna's Thursday announcement of lower than expected earnings and a slashed sales forecast.

BioNTech, which also developed a vaccine with partner Pfizer, sank as much as 20%. BioNTech is set to report earnings next week.

Oral treatments for COVID-19 would be a game-changer, as these would allow patients to be treated at home, different from the current treatments that require a clinical setting and professional administration.