STING Platform

About Next-Generation STING Agonists

STimulator of INterferon Genes, or STING, is a protein that has the power to activate the body’s innate immune system. Targeting this protein gives us the potential to stimulate the body’s immune response in the presence of cancer.

We are developing our STING agonist compounds as potential immunotherapeutic agents for the treatment of selected cancers. Immunotherapy has emerged in recent years as a transformative approach for the treatment of cancer. The induction of interferons and interferon-stimulated genes in tumor cells and within the tumor microenvironment has been shown to modulate the host-immune response and induce apoptosis of tumor cells. Activation of the STING pathway can result in the induction of cellular interferons and cytokines while promoting a strong anti-tumor response through the induction of innate and adaptive immune responses. Therapeutically targeting the STING pathway could turn an immunologically “cold” tumor into a “hot” one, making it more likely to respond to other forms of immunotherapy, such as immune checkpoint inhibitors.

All of Spring Bank’s next-generation STING agonists are specifically designed to be conjugated with antibodies as antibody-drug conjugates (ADCs). ADCs represent a novel platform to enable the targeted delivery of payload molecules. Furthermore, conjugation of a payload molecule to an antibody that has its own efficacy profile could allow for a single drug with enhanced potency and safety compared to either mechanism alone. We believe the chemistry used to develop our STING agonists is differentiated from first generation STING agonists because preclinical studies have shown that our molecules allow for site-specific conjugation to other therapeutic modalities, including antibodies, to form ADCs. Our STING agonists, in combination with an antibody to form an ADC, could provide targeted delivery to the tumor site to better achieve anti-tumor efficacy.

About SB 11285

We are advancing our internally-developed STING agonist product candidate, SB 11285, as a next-generation immunotherapeutic cyclic dinucleotide for the treatment of selected cancers. In our preclinical studies in multiple tumor-derived cell lines, we have observed SB 11285 to cause the induction of cytokines consistent with engagement of the STING target, as well as cell death and apoptosis. Based on our preclinical studies performed to date, SB 11285 has demonstrated efficacy in multiple rodent tumor models when administered intravenously or intratumorally. We believe that SB 11285 may be administered clinically by multiple routes of administration, enabling SB 11285 to target a variety of tumors at various anatomic sites. Furthermore, SB 11285 has the potential to be used in combination with other therapeutic modalities to enhance efficacy.

Clinical Trials

We initiated a Phase 1a/1b trial for SB 11285 in the third quarter of 2019, which is currently being conducted at multiple sites in the United States. Phase 1a of this trial is a dose-escalation study with intravenously-administered (IV) SB 11285 monotherapy which allows combination with a checkpoint inhibitor after the completion of the first two cohorts of the monotherapy trial. Phase 1b of this trial is designed to explore IV SB 11285 antitumor activity in combination with a checkpoint inhibitor in tumor types expected to be responsive to immunotherapy. This trial is designed to determine a recommended phase 2 dose in combination with a checkpoint inhibitor.

In the first quarter of 2020, we announced a clinical collaboration with Roche to explore the co-administration of SB 11285 with Roche’s PD-L1 checkpoint inhibitor atezolizumab (Tecentriq®) in patients with advanced solid tumors.

For more information related to this trial, please click here