Immunosynthen STING-Agonist ADC Platform & Pipeline

Immunosynthen is our novel immunostimulatory ADC platform designed to take ADCs beyond traditional cytotoxic drugs to targeted stimulation of the innate immune system. Through the safe and efficient delivery of a novel immunomodulatory STING agonist, ADCs created with our Immunosynthen platform have the potential to address the challenges of efficacy, delivery and tolerability.

Stimulator of Interferon Genes (STING) is a well-studied innate immune pathway capable of inducing anti-tumor immune activity. Our preclinical data show that the anti-tumor activity of Immunosynthen STING-agonist ADCs involves the targeted activation of the STING pathway in both tumor-resident immune cells and in tumor cells, in an antigen binding-dependent manner. This one-two punch provides the potential for enhanced anti-tumor activity with a STING-agonist ADC when compared to other innate immune approaches that activate only the immune cells. Further, we have generated preclinical data across multiple targets and tumor models showing complete regression of tumors in vivo after a single low, well-tolerated dose, consistent with increased cytokine expression and immune cell infiltration within the tumor and immune memory. In addition, we have demonstrated the tolerability and excellent pharmacokinetic profile of Immunosynthen ADCs in non-human primates, after multiple IV doses and at exposures significantly higher than those required for robust efficacy in mice.

To learn more, see our Immunosynthen STING-Agonist ADC Platform and Pipeline webinar

We are building a deep pipeline of Immunosynthen ADCs with a broad range of clinical indications and deep potential for value-creating partnerships. Our first Immunosynthen ADC development candidate, XMT-2056, is in IND-enabling studies and is expected to enter a Phase I dose escalation clinical study in mid-2022.

Immunosynthen Advantages

ADCs are ideally suited to overcome the limitations of free STING agonists and offer a highly differentiated approach from other innate immune activators

  • Systemic Administration with Targeted Delivery: ADCs have the convenience of systemic administration while providing targeted delivery specifically to the tumor, including metastatic lesions.
  • Improved Therapeutic Index: Conjugation of the STING agonist provides protection in the systemic circulation to minimize off-target effects.
  • Enhanced Pharmacokinetic (PK) Properties: The prolonged PK of ADCs and active uptake through internalization can overcome PK and permeability issues of the free agonists, resulting in sustained activation of the innate immune response.
  • Immunosynthen STING ADCs Deliver a One-Two Knockout Punch: Target-dependent delivery to both tumor cells and tumor-resident immune cells results in innate immune activation of both cell types and potent and robust antitumor responses and immune memory.