A Vaccine (PolyPEPI1018 Vaccine) and TAS-102 for the Treatment of Metastatic Colorectal Cancer

This phase Ib trial studies the safety and side effects of a vaccine (PolyPEPI1018 vaccine) in combination with TAS-102 in treating patients with colorectal that has spread to other parts of the body (metastatic). PolyPEPI1018 peptide vaccine is used to immunize against proteins present on the surface of tumor cells. This vaccine can activate the body's immune cells, called T cells. T cells fight infections and can also kill cancer cells. TAS-102 may help block the formation of growths that may become cancer. Giving PolyPEPI1018 and TAS-102 may kill more tumor cells in patients with metastatic colorectal cancer.

PRIMARY OBJECTIVE I. To evaluate the safety and tolerability of multiple doses of colorectal cancer peptide vaccine PolyPEPI1018 (PolyPEPI1018) with trifluridine and tipiracil hydrochloride (TAS-102) in patients with metastatic colorectal cancer (mCRC). SECONDARY OBJECTIVES: I. To evaluate initial efficacy of PolyPEPI1018 with TAS-102 by evaluating progression free survival (PFS). II. To evaluate initial efficacy of PolyPEPI1018 with TAS-102 by evaluating objective response rate (ORR). III. To evaluate initial efficacy of PolyPEPI1018 with TAS-102 by evaluating duration of response (DoR). IV. To evaluate initial efficacy of PolyPEPI1018 with TAS-102 by evaluating overall survival (OS). CORRELATIVE OBJECTIVES: I. Comparison of clinical benefit characteristics (ORR, PFS, OS or DoR) of the study with historical data of TAS-102. II. Correlations between personal epitopes (PEPIs) identified by candidate CDx and T cell responses measured by enzyme-linked immune absorbent spot (ELISPOT). III. To evaluate correlation between immune correlatives (T-cell responses in the blood and tumor and clinical benefit \[ORR, PFS, OS or DoR\]). IV. To evaluate correlation between PEPIs/AGPs predicted by candidate CDx and clinical benefit (ORR, PFS, OS or DoR). V. To evaluate the immunogenicity of PolyPEPI1018 by measuring both effector and memory T cell responses, VI. To evaluate immune activity of PolyPEPI1018 at tumor level (level of tumor infiltrating lymphocytes). VII. To identify PEPIs (Personal EPItopes capable of inducing T cell responses in an individual) and AGPs (predicted number of expressed antigens likely hit by T cells) from PolyPEPI1018 in each patient. OUTLINE: Patients receive PolyPEPI1018 subcutaneously (SC) at 4 injection sites on days 1 and 15 and trifluridine and tipiracil hydrochloride orally (PO) twice daily (BID) on days 1-5 and 8-15. Treatment repeats every 28 days for up to 7 cycles in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up every 3 months for up to 1 year.