Codiak Initiates Patient Dosing in Phase 1/2 Clinical Trial of exoSTING™ for the Treatment of Solid Tumors

Oct. 1, 2020 11:00 UTC
  • exoSTING is the second engineered exosome candidate generated from Codiak’s engEx™ Platform to enter clinical development
  • exoSTING is engineered to provide targeted delivery of Codiak’s proprietary STING agonist to antigen presenting cells in the tumor microenvironment

CAMBRIDGE, Mass.--(BUSINESS WIRE)-- Codiak BioSciences, Inc., a clinical-stage company focused on pioneering the development of exosome-based therapeutics as a new class of medicines, today announced the initiation of patient dosing in its Phase 1/2 clinical trial of exoSTING. exoSTING is a novel exosome therapeutic candidate engineered with the company’s engEx Platform and designed to deliver Codiak’s proprietary STING (stimulator of interferon genes) agonist specifically to tumor-resident antigen presenting cells (APCs) to locally activate the innate immune response. The trial, which will study exoSTING in solid tumors, is Codiak’s second human clinical trial and the second clinical development program the Company has initiated in the past month.

“We are enormously proud to now have both of our lead candidates in the clinic, the result of years of engineering and manufacturing innovation and a significant step forward towards fulfilling our goal of pioneering the development of engineered exosomes as a new class of medicines for diseases with high unmet medical needs,” said Douglas E. Williams, Ph.D., CEO, Codiak. “With exoSTING, the data from our in vitro and in vivo preclinical studies support our desired product profile, demonstrating that we can achieve targeted engagement of the STING pathway to potentially overcome the lack of cell specificity, tolerability, and limited single-agent antitumor activity associated with previous STING agonists.”

exoSTING is an exosome therapeutic candidate engineered with Codiak’s engEx Platform to incorporate its proprietary STING agonist inside the lumen of the exosome while expressing high levels of the exosomal protein, PTGFRN, on the surface. The high-level display of PTGFRN is designed to promote targeted delivery of Codiak’s proprietary STING agonist into APCs in the tumor microenvironment.

Engagement of the STING pathway has been validated to elicit an anti-tumoral response, yet therapeutic development has been generally limited by non-selective cell delivery, off-target toxicity to important immune cells in the tumor and dose-related toxicity due to leakage of the STING agonist into the circulation. In preclinical models of exoSTING, the targeted delivery of a STING agonist to tumor resident APCs promoted localized innate immune activation, T cell attraction and expansion in the tumor, and the development of systemic immunity not observed with a STING agonist delivered without exosomes (e.g., “free”).

The Phase 1/2 dose escalation clinical trial of exoSTING is designed to investigate safety, tolerability, pharmacological activity, and objective tumor response in patients with advanced/metastatic, recurrent, injectable solid tumors, with a focus on tumors likely to be enriched in APCs. Examples of such tumors include metastatic head and neck squamous cell cancer (HNSCC), triple-negative breast cancer (TNBC), anaplastic thyroid carcinoma (ATC), and cutaneous squamous cell carcinoma (cSCC). Safety, biomarker and preliminary efficacy data from the dose-escalation phase of the trial is expected in mid-2021. As part of the Phase 2 portion of the trial, Codiak intends to enroll further expansion cohorts of patients at the optimal exoSTING dose to be identified in the Phase 1 portion of the clinical program.

About exoSTING™

exoSTING is Codiak’s exosome therapeutic candidate engineered to incorporate a proprietary STING (stimulator of interferon genes) agonist inside the lumen of the exosome while expressing the exosomal protein, PTGFRN, on the exosome surface to facilitate specific uptake in tumor-resident antigen presenting cells (APCs). Codiak believes that exoSTING has the potential to overcome certain limitations of free STING agonists, and enhance the therapeutic index and selectivity of delivery to desired cells in the tumor microenvironment.

Codiak is developing exoSTING for the treatment of multiple solid tumors enriched in the target APCs. exoSTING has demonstrated encouraging activity in preclinical models and is now being evaluated in a Phase 1/2 clinical trial in patients with advanced/metastatic, recurrent, and injectable solid tumors. Future development of exoSTING may be expanded to neuro-oncology indications such as glioblastoma and leptomeningeal cancer disease.

About the engEx™ Platform

Codiak’s proprietary engEx Platform is designed to enable the development of engineered exosome therapeutics for a wide spectrum of diseases and to manufacture them reproducibly and at scale to pharmaceutical standards. By leveraging the inherent biology, function and tolerability profile of exosomes, Codiak is developing engEx exosomes designed to carry and protect potent drug molecules, provide selective delivery and elicit the desired pharmacology at the desired tissue and cellular sites. Through its engEx Platform, Codiak seeks to direct tropism and distribution by engineering exosomes to carry on their surface specific targeting drug moieties, such as proteins, antibodies/fragments, and peptides, individually or in combination. Codiak scientists have identified two exosomal proteins that serve as surface and luminal scaffolds. By engineering the exosome surface or lumen and optimizing the route of administration, Codiak aims to deliver engEx exosomes to the desired cell and tissue to more selectively engage the drug target, potentially enhancing the therapeutic index by improving potency and reducing toxicity.

About Codiak BioSciences

Codiak is a clinical-stage biopharmaceutical company focused on pioneering the development of exosome-based therapeutics, a new class of medicines with the potential to transform the treatment of a wide spectrum of diseases with high unmet medical need. By leveraging the biology of exosomes as natural intercellular transfer mechanisms, Codiak has developed its proprietary engEx Platform to expand upon the innate properties of exosomes to design, engineer and manufacture novel exosome therapeutic candidates. Codiak has utilized its engEx Platform to generate a deep pipeline of engineered exosomes aimed at treating a broad range of disease areas, spanning oncology, neuro-oncology, neurology, neuromuscular disease and infectious disease. For more information, visit

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Lindy Devereux
Scient PR
T: 646-515-5730


Source: Codiak BioSciences, Inc.

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