Most Hodgkin Lymphoma (HL) patients can be cured with chemotherapy, radiotherapy or combined modality treatment. However, current treatment is associated with toxicities, such as infertility, cardiovascular damage and secondary malignancies (Fuchs et al, 2006). Moreover, about 10% of all HL patients have refractory disease despite high dose chemotherapy and autologous or allogeneic stem cell transplantation (Cashen & Bartlett, 2008; Laport, 2008; Sureda et al, 2008).

Lenalidomide (Revlimid), a thalidomide-derivate, belongs to a novel class of immunomodulatory drugs (IMIDs) approved for the treatment of Multiple Myeloma and Myelodysplastic Syndrome with deletion (-q5)(Chanan-Khan & Cheson, 2008). Lenalidomide has multiple modes of action, including direct induction of apoptosis in tumour cells, antiangiogenic effects and the activation of immune cells, such as Natural Killer cells and T-cells (Marriott et al, 2001; Bartlett et al, 2004). Apoptosis resistance, increased neoangiogenesis and impaired immunity critically contribute to HL (Re et al, 2005; Enblad et al, 2007). We therefore hypothesized that single agent lenalidomide might be active in HL patients who have failed conventional chemotherapy.