ADP-600

The Phase I/II clinical trial will investigate the T cell therapy in patients with haematological malignancies. Credit: Yomal2233 via Shutterstock. Genome writing company Replay Bio has had its investigational new drug (IND) application cleared by the US Food and Drug Administration (FDA) to initiate a clinical trial of its T cell therapy for haematological malignancies. PRAME TCR/IL-15 NK (SY-307) is an engineered T cell receptor natural killer (TCR-NK) cell therapy, targeting preferentially expressed antigens in melanoma (PRAME). The candidate is being developed by Syena, a company launched by Replay and MD Anderson. Syena is working alongside the University of Texas MD Anderson Cancer Center to fund the Phase I/II clinical trial in patients with relapsed/refractory acute myeloid leukaemia (AML) and myelodysplastic syndromes (MDS). In the study, 44 patients will be administered the TCR therapy following lymphodepletion. This is a process that uses chemotherapy to reduce or deplete lymphocytes. Standard doses of fludarabine/cyclophosphamide (Flu/Cy) and decitabine chemotherapies will be used for lymphodepletion in this trial, which is anticipated to begin in Q3 2024. The PRAME-directed cell therapy is Syena’s second programme to enter the clinic following NY-ESO-1 TCR/IL-15 NK, a first-in-class cell therapy for relapsed or refractory multiple myeloma. The candidate is currently being investigated in a Phase I/II study (NCT06066359), which started in November. An additional study in patients with synovial sarcoma and myxoid/round cell liposarcoma that tests the same therapy is expected to begin, following IND clearance from the FDA in June 2023. See Also: Xyphos and Poseida to develop allogeneic cell therapies for cancer Pfizer and Genmab’s Tivdak wins full FDA approval for cervical cancer Since then, Syena has also entered a research collaboration with JURA Bio for the development of TCR-based therapies. PRAME is a highly immunogenic antigen that is expressed on lots of different cancer cell types, making it an attractive target for cell therapy-mediated cancer immunotherapy. In February 2024, Immunocore and BMS teamed up to investigate the PRAME-targeting candidate IMC-F106C as a first-line treatment for melanoma. At the same time, other projects involving PRAME-directed therapies have been in development for a while. After a nine-year cell therapy-related collaboration between GSK and Adaptimmune , GSK returned the rights to its preclinical PRAME-targeted programme to Adaptimmune last year, which received £30m ($37.5m) in the process. Despite this, Adaptimmune announced plans to advance the therapy, ADP-600, into clinic this year following positive preclinical safety and potency data. Replay launched into the cell therapy scene with $55m in seed financing in July 2022, backed by global investment company KKR and fund OMX Ventures. Artis Ventures, Lansdowne Partners, SALT, DeciBio Ventures, and Axial also participated in that round. In the announcement accompanying the IND clearance, professor of stem cell transplantation and cellular therapy at MD Anderson Katy Rezvani said: “This is an exciting milestone in the development of ‘off-the-shelf’ engineered TCR-NK cell therapies to address significant unmet medical needs. “Our hope is the PRAME studies, initially in haematological malignancies and then in solid tumours, will further advance our understanding of the potential for engineered TCR-modified NK cells to benefit patients with relapsed/refractory myeloid malignancies.”