Shares of Atea Pharmaceuticals Inc. /zigman2/quotes/222210381/composite AVIR +3.71% took a 70.7% nosedive on heavy volume toward a record low in morning trading Tuesday, after the biopharmaceutical company said a Phase 2 trial of its oral treatment of SARS-CoV-2 virus in an outpatient setting failed to meet its primary endpoint. Trading volume swelled to 21.6 million shares, compared with the full-day average of about 2.7 million shares. The company said primary endpoint of the AT-527 study was a reduction from baseline of SARS-CoV-2 in patients with mild or moderate COVID-19 compared with placebo. The company said there was data that suggested AT-527 has produced antiviral activity in high-risk patients with underlying health conditions. The company said it, and its partner Roche, are assessing potential modifications to the Phase 3 trial, so the expected time when data from the trial will be expected has been pushed out to the second half of 2022 from the second half of 2021. The stock, which went public on Oct. 30, has now shed 71.5% year to date, while the iShares Biotechnology ETF /zigman2/quotes/206189322/composite IBB +0.33% has gained 3.8% and the S&P 500 /zigman2/quotes/210599714/realtime SPX +1.42% has advanced 19.8%.