Achilles Therapeutics plc is a United Kingdom-based clinical-stage immuno-oncology biopharmaceutical company. The Company is engaged in developing precision T cell therapies to treat multiple types of solid tumors. Its lead product is a precision tumor-derived T cell therapy targeting clonal cancer neoantigens. Its pipeline includes Chiron: Advanced Non-Small Cell Lung Cancer, Thetis: Melanoma (Monotherapy), Thetis: Melanoma (PD-1 Combination), and other indications. It is focused on advancing cancer therapies through its work in the field of tumor evolution. Its platform enables to identify mutations formed early in the development of a cancer that give rise to antigens that are expressed by all of a patient's cancer cells but are absent from healthy tissue. It refers to this class of solid tumor targets as clonal neoantigens. To identify clonal neoantigens in a patient, it has developed a bioinformatic platform called PELEUS.