Immunotherapy and Carbon Ion Radiotherapy In Solid Cancers With Stable Disease

Immunotherapy has become the standard of care in different advanced malignancies. Its effectiveness in the palliative setting was demonstrated by several phase III trials. However, the response rate varies according to the cancer under study and to the line of treatment. A potential way to improve the activity of single agent immune checkpoint inhibitors (ICIs) is to enhance the clinical response through further antitumor agents, including radiotherapy. Studies showed that carbon ions may lead to a broader immunogenic response; for their dosimetric characteristics it is possible to reduce integral dose sparing immune cells to direct and sustain a tumor specific immune response. Considering the available preclinical and clinical evidence together, the goal of this study is to explore the feasibility and the clinical activity of adding carbon ion radiotherapy (CIRT), employed with a fractionation strategy comparable to stereotactic body radiation, to ICIs in advanced malignancies where immunotherapy is currently the standard of care.

This is a multicenter, open label, non-randomized phase II clinical trial aiming to assess the feasibility and the clinical activity of adding CIRT to ICIs in cancer patients that have obtained a disease stability (SD) with pembrolizumab administered as per standard of care. At study entry, hypofractionated CIRT will be delivered to one measurable lesion previously untreated with local approaches.CIRT will be performed at Fondazione CNAO, Pavia