Company: IOBT
Filing Date: 2025-03-31
Form Type: 10-K
Source: 0000950170-25-047744
Chunk: 37

Company: IO Biotech, Inc.
Filing Date: 2025-03-31
Form: 10-K
Item: Item 1
Chunk 37
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 Safety data from these trials is included in the tables below. 

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Table 9: Adverse Events Summary of Completed Investigator Initiated Trials 

The following table summarizes adverse events observed in our trials or reported by the clinical investigators in other trials involving our product candidates: 

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Table 6: Ongoing Investigator Initiated Trials 

The clinical trials listed in Table 6 above are investigator-initiated trials and accordingly we do not have control over the timing of such trials.

IO112 (Arginase 1) 

IO112 is our fully owned, novel investigational product candidate containing a single Arginase 1-derived peptide designed to engage and activate Arginase 1-specific human T cells. IO112 is designed to target T cells that recognize epitopes derived from Arginase 1, which is an immunoregulatory enzyme highly expressed in difficult-to-treat tumors associated with high levels of MDSCs including renal cell carcinoma, head and neck, breast, pancreatic, ovarian, colorectal and prostate cancers. Arginase overexpression is a well-documented tumor escape mechanism.

Arginase 1 contributes to immune regulation by catabolizing and limiting the availability of arginine, an essential amino acid for immune effector cell survival and growth. Arginase overproduction by immune suppressive cells like myeloid derived suppressor cells and tolerogenic dendritic cells is a well-documented tumor escape mechanism. Increased levels of arginase have been detected on tumor and immune cells in several solid tumor types. 

Preclinical Development 

IO112 is designed to selectively engage and activate cancer patients’ own T cells to attack Arginase 1-expressing target cells. Upon activation, T cells secrete proinflammatory cytokines such as IFN and TNF, thereby contributing to immune modulation of microenvironment. 

Immunotherapeutic activity of murine Arginase 1 peptide therapy (mIO112) has been observed in multiple Arginase 1-expressing tumor models. Arginase 1 treatment resulted in a concomitant reduction of Arginase 1+ cells and an increased influx of T cells into the TME. The treatment approach enhanced the anti-tumor effect of an anti-PD-1 antibody treatment in a colon adenocarcinoma model, MC38. 

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Figure 18: Arginase 1 Therapy in Mouse Colon Cancer Model 

Treatment combining Arginase 1 therapy and a