Ironwood Pharmaceuticals, a Nasdaq-listed GI-focused healthcare company, has agreed to acquire VectivBio Holding, a Basel-based clinical-stage biopharmaceutical company pioneering novel, transformational treatments for severe rare gastrointestinal conditions, for US$17.00 per share in an all-cash transaction with an estimated aggregate consideration of approximately US$1bn, net of VectivBio cash and debt. Ironwood expects to finance the acquisition…