Sidewinder Therapeutics emerged from stealth with an oversubscribed $137 million Series B, pitching a bispecific ADC approach designed to improve tumor targeting while reducing toxicities. The San Diego company said it plans to advance a lead program into the clinic in 2027. Backers include OrbiMed and Novartis’ venture arm, signaling renewed late-stage ambition around ADC next-generation engineering. Sidewinder’s focus on bispecific designs aims to address limitations seen with single-target constructs in solid tumors such as colorectal cancer and squamous cell carcinomas. The financing also adds to a broader pattern of capital flowing into ADC platform companies capable of producing multiple payload/linker variants and combinations.