Zymeworks (ZYME) shares slumped 46% pre-bell Tuesday, adding to Monday's losses.
Arvinas (ARVN) shares retreated 41% after the company and Pfizer (PFE) said their phase 3 trial of vepdegestrant for the treatment of breast cancer failed to reach statistical significance in improvement in progression free survival in the intent-to-treat population.
Evolus (EOLS) shares fell 36% after Monday's 6.6% loss.
Stoke Therapeutics (STOK) shares decreased 36% following a muted session.
Medallion Financial (MFIN) shares were down 32% after a 2.4% gain in the previous session.