Fortitude Biomedicines, a new biopharmaceutical company headquartered in Waltham, Massachusetts, launched with USD 13 million in seed financing. The biotech is built around a platform that enables the design of antibody drug conjugates (ADCs) carrying molecular glue payloads, with the aim of addressing resistance seen with conventional ADCs in oncology and extending the modality to autoimmune diseases.

The financing round was co-led by K2 Bio Partners, Shanghai Healthcare Angel Capital (SHAC), and Elikon Venture, with additional participation from Everjoy Fortune and Taihill Venture. Proceeds will fund Investigational New Drug (IND) enabling studies for the company’s lead immune-cell targeting biologic and support advancement of additional programs using the proprietary GLUE-DAC platform, a next-generation ADC discovery engine that combines molecular glue degrader payloads with antibodies for guidance, potentially expanding therapeutic windows and overcoming resistance mechanisms in oncology and autoimmune indications.

The GLUE-DAC platform is based on research from the Baylor College of Medicine (BCM) in Houston, Texas, led by Professor Jin Wang, who co-founded Fortitude with CEO Dr. Jesse Chen. Chen is a serial entrepreneur who previously co-founded TRIANA Biomedicines and Avilar Therapeutics, both biotechs involved in targeted protein degradation therapeutics including molecular glues.

Industry context

There is now broad industry interest in platforms that enhance ADC performance and tackle resistance challenges. A string of biotechs and multinational pharma companies are actively exploring the combination of targeted protein degradation with antibody-based delivery systems to create degrader-antibody conjugates (DACs) or molecular glue-antibody conjugates (MACs), including a wave of deal making.

Korean firm Orum Therapeutics, the pioneer in the class, was the first to take a DAC into the clinic. Bristol Myers Squibb moved to acquire Orum’s anti-CD33 antibody-enabled GSPT1 degrader for acute myeloid leukemia in a 2024 deal. Nurix Therapeutics partnered with Pfizer-owned Seagen in 2023 for development of DACs, a deal worth up to USD 3.4 billion. And C4 Therapeutics partnered with Merck & Co., in a 2023 partnership worth up to USD 2.5 billion. Other protein degradation pioneers such as Arvinas and Kymera Thereapeutics are also exploring combinations with antibodies.