mRNA-Based Anti-TCR CDR3 Tumour Vaccine for T-Cell Lymphoma

Efficient vaccination can be achieved by injections of in vitro transcribed mRNA (ivt mRNA) coding for antigens. This vaccine format is particularly versatile and allows the production of individualised vaccines conferring, T-cell immunity against specific cancer mutations. The CDR3 hypervariable regions of immune receptors (T-cell receptor, TCR or B-cell receptor, BCR) in the context of T- or B-cell leukaemia or lymphoma are targetable and specific sequences, similar to cancer mutations. We evaluated the functionality of an mRNA-based vaccine designed to trigger immunity against TCR CDR3 regions in an EL4 T-lymphoma cell line-derived murine in vivo model. Vaccination against the hypervariable TCR regions proved to be a feasible approach and allowed for protection against T-lymphoma, even though immune escape in terms of TCR downregulation paralleled the therapeutic effect. However, analysis of human cutaneous T-cell lymphoma samples indicated that, as is the case in B-lymphomas, the clonotypic receptor may be a driver mutation and is not downregulated upon treatment. Thus, vaccination against TCR CDR3 regions using customised ivt mRNA is a promising immunotherapy method to be explored for the treatment of patients with T-cell lymphomas

Radiotherapy as a Treatment Option for Local Disease Control in Primary Cutaneous Diffuse Large B-Cell Lymphoma, Leg Type

BACKGROUND Primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL, LT) is an aggressive lymphoma variant. Anthracycline-based chemotherapy with rituximab is recommended as first-line treatment. Radiotherapy (RT) has been considered as a therapeutic option for local disease control in patients with solitary or localized lesions. METHODS We report the results of a retrospective analysis of PCDLBC, LT patients treated either with RT alone or with physician's decision as first-line treatment, aiming to assess disease progression and/or first recurrence in these treatment groups. RESULTS We retrospectively analyzed 20 patients treated either with RT alone (n = 8) or with investigator's choice treatment (n = 12), which included chemotherapy alone or combined with local therapy (RT and wide local excision). Complete response (CR) was achieved in 8 patients from the first group and 9 patients from the second group, with 1 treatment failure. Six patients treated with RT alone progressed with a median time to progression (TTP) of 12.5 months. In the second group, 5 patients progressed with a median TTP of 5.2 months. RT showed good local disease control in both groups without any skin relapses during the follow-up period. CONCLUSION RT as first-line monotherapy followed by watchful waiting did not significantly improve the overall risk of disease progression but resulted in good local disease control. After progression, RT could still easily be combined with systemic treatment. The strength of this analysis needs to be evaluated in a larger patient cohort