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Exhibit 99.1 MARKER Therapeutics Marker Therapeutics Reports First Quarter 2021 Operating and Financial Results Marker continues to advance Phase 2 AML trial , recently dosing first patient Company closed financing extending cash runway into Q1 2023 Company to host conference call and webcast today at 5:00 p.m. ET Houston , TX — May 12 , 2021 — Marker Therapeutics , Inc. ( Nasdaq : MRKR ) , a clinical - stage immuno - oncology company specializing in the development of next - generation T cell - based immunotherapies for the treatment of hematological malignancies and solid tumor indications , today provided a corporate update and reported financial results for the first quarter ended March 31 , 2021 . " We had a productive first quarter supported by our recently completed financing , strengthening our overall cash position and enabling continued growth and expansion of our Multi - TAA pipeline , ” Peter L. Hoang , President & CEO of Marker Therapeutics . “ In addition , we continue to make strong progress on both the clinical and manufacturing fronts . In March , we dosed the first patient in the safety lead - in portion of our Phase 2 trial in post - transplant acute myeloid leukemia , or AML , and continue to activate clinical sites . In parallel , we continue to optimize the MT - 401 cell therapy manufacturing process , which we believe could result in an increase in the number of T cells available for patient administration — among other benefits — as we prepare to operationalize our new in - house cGMP facility in the first half of the year . " PROGRAM UPDATES In March 2021 , Marker dosed the first patient in the safety lead - in portion of its Phase 2 trial in AML , which is expected to enroll a total of six patients : three of which will be treated with MT - 401 manufactured with a legacy reagent , and the remaining three to be treated with study drug manufactured with a new reagent from an alternate supplier . The clinical operations team has made considerable progress in opening sites to enroll patients for the safety lead - in portion of the AML trial . The Company has also received commitments from additional clinical sites to participate in the Phase 2 AML trial following the safety lead - in phase and anticipates activating a total of approximately 20 sites . Marker continues to streamline and simplify the MT - 401 manufacturing process , which could potentially result in a product with a superior T cell phenotype and improved antigen specificity as compared to the original process . The new process improvements have been updated in the CMC section of the IND and will be used for all patients in the Marker AML Phase 2 clinical trial .