Upstream Bio, a Phase 2 respiratory biotech developing an antibody that targets the TSLP receptor, raised $255 million by offering 15 million shares at $17, the high end of the range of $15 to $17. The company originally planned to offer 12.5 million shares. At pricing, Upstream commands a fully diluted market value of $948.3 million.
The company's lead candidate is verekitug, a monoclonal antibody being developed to treat severe respiratory disorders. Verekitug aims to target and inhibit the Thymic Stromal Lymphopoietin receptor, and Upstream Bio has advanced it to into Phase 2 trials to treat severe asthma and chronic rhinosinusitis with nasal polyps. It plans to also enter it into a Phase 2 trial for chronic obstructive pulmonary disease.
Upstream Bio plans to list on the Nasdaq under the symbol UPB. J.P. Morgan, TD Cowen, Piper Sandler, and William Blair acted as joint bookrunners on the deal.
