Arsanis Halts Phase II Trial of Pneumonia Candidate ASN100

Arsanis said today it has ended a Phase II trial for its sole clinical-phase candidate, ASN100, concluding that the monoclonal antibody combination would fail to prove its effectiveness in high-risk, mechanically ventilated patients with Staphylococcus aureus pneumonia.The decision touched off a stock selloff that sent shares of Arsanis losing nearly three quarters of their value this morning in premarket trading. The share price plunged about 73%, from $18.19 at yesterday’s close of tradi