The role of biotherapies (interleukins, interferons and erythropoietin) in multiple myeloma.

During the last decade, the availability of large numbers of cytokines and growth factors has greatly favoured the use of biotherapies in several haematological disease. For MM, the majority of clinical studies have dealt with the use of IFN-alpha. From these studies it appears that IFN-alpha has a definite role in the treatment of MM especially in the setting of minimal residual disease, as maintenance therapy after response to conventional therapies or HDC followed by BMT procedures or PBSCI. Data on the use of EPO have consistently demonstrated the role of this growth factor in ameliorating the grade of anaemia as well as the quality of life of those MM patients whose disease is complicated by the presence of a severe or moderate anemia. Despite the large amount of experimental data indicating a role for IL-2 and IL-6 in controlling tumour growth, there are only a few clinical studies dealing with their use in MM. From these, it appears that IL-2 and anti-IL-6 antibodies should be further investigated as therapeutic tools useful in maintaining responses, because results show that they arrest tumour progression rather than aid, tumour regression. Finally, in the next years, there will be a wider diffusion of biotherapies in MM that should take into account the roles that IL-1 beta and TNF alpha play in myeloma cell proliferation and bone destruction and the finding that retinoic acid is capable of inhibiting the growth of human myeloma cells in vitro through modulation of IL-6 and its receptor.