Stipple Bio stepped out of stealth with an oversubscribed $100 million Series A to advance its lead antibody-drug conjugate candidate, STP-100, expected to enter clinical studies in early 2027. The company also said the financing will fund additional programs using its Pointillist platform for tumor-specific cell surface epitope discovery and engineering. STP-100 is designed to address off-target toxicity, a recurring development constraint in ADCs that can narrow therapeutic windows. Stipple characterized its differentiated approach as upstream of the ADC payload itself, focusing on how binding is engineered to improve discrimination between tumor and healthy tissue. The scale of the raise highlights investors’ continued willingness to fund ADC next-generation targeting strategies rather than only payload chemistry.