Exhibit 99.1 Xilio Therapeutics Announces Pipeline and Business Updates and First Quarter 2024 Financial Results WALTHAM, Mass., May 14, 2024 -- Xilio Therapeutics, Inc. (Nasdaq: XLO), a clinical- stage biotechnology company discovering and developing tumor-activated immuno-oncology therapies for people living with cancer, today announced pipeline progress and business updates and reported financial results for the first quarter ended March 31, 2024. Plan to report clinical data for XTX101 and XTX301, a tum ...