Boulevard Bio exited stealth with about $65 million in launch financing to pursue B cell-directed multi-specific antibodies for chronic autoimmune disease. Backed entirely by Deerfield Management, the company is advancing programs built inside Deerfield’s internal 3DC platform before spinning out as an independent entity. The lead asset, BLVD101, is a bispecific antibody targeting BAFF and APRIL, cytokines linked to B cell survival and activation. Boulevard plans an initial clinical evaluation in IgA nephropathy, with interim Phase I signals suggesting the potential for quarterly dosing. The structure of the financing and platform build emphasizes a model where platform discovery and early clinical development are de-risked internally before independent capital raises—while still aiming for a differentiation based on dosing burden reduction.