Sequential intranodal immunotherapy induces antitumor immunity and correlated regression of disseminated follicular lymphoma

Advanced stage follicular lymphoma (FL) is incurable by conventional therapies. In the present pilot clinical trial, we explored the efficacy and immunogenicity of a novel in situ immunotherapeutic strategy. Fourteen patients with untreated or relapsed stage III/IV FL were included and received local radiotherapy to solitary lymphoma nodes and intranodal injections of low-dose rituximab (5 mg), immature autologous dendritic cells, and granulocyte-macrophage colony-stimulating factor at the same site. The treatment was repeated 3 times targeting different lymphoma nodes. Primary end points were clinical responses and induction of systemic immunity. Five out of 14 patients (36%) displayed objective clinical responses, including 1 patient with cutaneous FL who showed regression of skin lesions. Two of the patients had durable complete remissions. Notably, the magnitude of vaccination-induced systemic CD8 T-cell-mediated responses correlated closely with reduction in total tumor area (r = 0.71, P = .006), and immune responders showed prolonged time to next treatment. Clinical responders did not have a lower tumor burden than nonresponders pretreatment, suggesting that the T cells could eliminate large tumor masses once immune responses were induced. In conclusion, the combined use of 3 treatment modalities, and in situ administration in single lymphoma nodes, mediated systemic T-cell immunity accompanied by regression of disseminated FL.