“Boom-Boom” radioimmunotherapy of lymphomas: are two magic bullets better than one?

Since its first human use, dated back to 1987, radioimmunotherapy (RIT) of non-Hodgkin (NHL) lymphomas has undergone many vicissitudes, and we might be not too far from the truth by affirming that this is not the best time for it. As a matter of fact, the worldwide enthusiasm following the approval, at the beginning of this century, of the first two RIT compounds, ⁹⁰Y-ibritumomabtiuxetan (Zevalin^®) and ¹³¹I-tositumomab (Bexxar^®) for relapsed/refractory indolent NHL, was tempered by the success of new chemotherapy agents and of the rituximab maintenance strategies. Moreover, in case of relapse after optimized rituximab-including treatments, RIT showed a reduced efficacy both in aggressive and indolent NHLs. In addition, the absence of randomized phase III studies comparing RIT head-to-head with other agents and the physicians’ natural reluctance to refer patients to radionuclide treatments, have played in synergy against its use. At present, RIT is underused and, in February 2014, this has led to the withdrawal of Bexxar^® from the US market.