Treos Bio Enters into Clinical Collaboration to Evaluate its Polypeptide Cancer Immunotherapy PolyPEPI1018 in Combination with Roche’s PD-L1-Inhibitor

Treos Bio Limited (“Treos”), a clinical stage biotechnology company using data science and proprietary biomarkers to develop both precision off-the-shelf and personalized peptide cancer immunotherapies, today announced a clinical collaboration with Roche in which Treos will evaluate the combination of PolyPEPI1018, its lead product candidate, and atezolizumab, Roche’s PD-L1-inhibitor, in patients with late stage microsatellite stable metastatic colorectal cancer (MSS mCRC). A Phase I/II trial evaluating PolyPEPI1018 in combination with atezolizumab is expected to begin in Q4 2021.

“This collaboration with Roche affords Treos the unique opportunity to investigate more fully the potential of our off-the-shelf polypeptide cancer immunotherapy and its ability to boost the cancer-killing response of an anti-PD-L1 immunotherapy,” said Dr. Christopher C. Gallen, M.D., Ph.D., Chief Executive Officer of Treos. “Treos is eager to explore this combination as we work to meaningfully improve the clinical outcomes for patients living with MSS mCRC, a condition which accounts for approximately 85% of CRC worldwide.”

Treos completed a Phase I/II study of PolyPEPI1018 in the first-line maintenance setting in patients with MSS mCRC, OBERTO 101. The trial demonstrated that the therapy was safe and well-tolerated and induced T cell responses against multiple tumor targets. Robust immune responses by patients correlated to clinical benefits. Results were presented in a poster presentation at ASCO 2020.

“In the completed Phase I/II study, the immunotherapy induced a strong tumor-infiltrating lymphocytes (TIL) response against “cold tumors”, suggesting the potential to convert a “cold” tumor to a “hot” tumor and increase the effect of checkpoint inhibitors in difficult-to-treat solid tumors,” said Dr. Joleen Hubbard, Associate Professor of Medical Oncology at the Mayo Clinic Rochester and Principal Investigator in the Phase I/II study. “In addition, PolyPEPI1018 boosted the T cell responses against specific antigens to which patients had spontaneous immunity, suggesting a potential synergy between PolyPEPI1018 and anti-PD-L1 immunotherapies. Following the encouraging results from this trial, in which some patients experienced surprising clinical benefits, I look forward to treating patients with this new combination in the upcoming Phase I/II trial.”

Under the terms of the non-exclusive collaboration, Treos is responsible for conducting the study, with Roche providing all required doses of atezolizumab. Treos maintains full ownership of PolyPEPI1018.

About PolyPEPI1018

PolyPEPI-1018, Treos’ lead product candidate, is an off-the-shelf immunotherapy in clinical development for the treatment of metastatic colorectal cancer, co-developed with a candidate companion diagnostic. The therapy is in development as a first-line maintenance therapy and as a third-line treatment. The companion diagnostic uses Treos’ proprietary PASCal computational tool to identify Personal EPItopes (PEPIs) that are likely to induce antigen-specific T Cell responses in a patient.

About Treos Bio Limited

Treos Bio uses computational data science and proprietary biomarkers to develop precision off-the-shelf and personalized peptide-based cancer immunotherapies. The Company has developed a unique ability to match the antigens expressed by a specific cancer to the individual patient’s target recognition mechanism (HLA). This technology aims to address the challenge of the variability of an individual patient’s clinical responses to cancer immunotherapies. Treos’ lead candidate is PolyPEPI-1018, an off-the-shelf immunotherapy for the treatment of metastatic colorectal cancer, co-developed with a candidate companion diagnostic. Treos is also developing “off-the-shelf” personalized immunotherapies (PEPI Panel) for several types of solid tumors and has completed preclinical development of PolyPEPI immunotherapies in ovarian, breast, bladder, gastric and lung cancers and melanoma. The Company is also developing an investigational COVID-19 peptide vaccine, PolyPEPI-SCoV-2. Treos launched in February 2017 and has raised $28 million Series A funding led by shareholders of BXR Group and recently closed a $14 million investment round led by Outsized Ventures (formerly known as Luminous Ventures).