Pirtobrutinib and Mosunetuzumab for the Treatment of Relapsed/Refractory Grades 1-3A Follicular Lymphoma, PROMOTE-FL Trial

This phase II trial tests how well pirtobrutinib and mosunetuzumab work in treating patients with grade 1-3a follicular lymphoma (FL) that has come back after a period of improvement (relapsed) or that has not responded to previous treatment (refractory). Pirtobrutinib, a type of tyrosine kinase inhibitor, works by blocking the action of the Bruton tyrosine kinase (BTK) protein. The BTK protein signals cancer cells to multiply, and blocking it may help keep cancer cells from growing. It could also improve T cell fitness and decrease inflammation, therefore, may improve the efficacy and safety of T cell-based therapies, such as mosunetuzumab. Mosunetuzumab is a bispecific antibody that binds both T cells and the lymphoma cancer cells and harnesses T cells to interfere with the ability of cancer cells to grow and spread. Giving pirtobrutinib and mosunetuzumab together may kill more tumor cells in patients with relapsed or refractory grade 1-3a FL and potentially decreases some side effects of mosunetuzumab which are related to T cells being activated (e.g., cytokine release syndrome).