Early Stage Follicular LymphOma and RadioTherapy PLUS Anti-CD20 Antibody

The MIR study proved the effect of Rituximab in combination with a localized irradiation given in a standard dose. Together with the TROG 99.03 trial, this led to the recommendation of using this combined approach in early stage nodal follicular lymphoma. The GAZAI study is currently looking for the effect of a low dose radiotherapy of 2x2 Gy in combination with Obinutuzumab. The combination seems to show a high CR rate based on the 50% of the patients. This is in contrast to the FORT trial, which showed an inferiority of the 4 Gy dose compared to the standard dose (24 Gy) in terms of response and progression free survival. The goal of the FORTplus trial is to prove (1) the non-inferiority of LDRT (4Gy) in a combined approach with an anti-CD20-antibody. In case of non-inferiority, a possible (2) superiority of the Obinutuzumab + LDRT should be tested against Rituximab + standard dose using the same test set. The radiation dose can significantly be reduced to 16% of the standard dose if (1) is confirmed. Knowing the data of the FORT trial, this would have a significant influence on the treatment of the disease worldwide even if the difference in the CR rate at week 18 is not as high as currently in the historical comparison expected.