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The search for new therapeutic approaches to haematological malignant disease involves exploitation of the antitumour potential of adaptive immunity—the most specific killing system against cancer currently known. Here, we summarise immunological strategies behind active specific immunotherapy, and describe the clinical and immunological results from trials published to date. Available data in humans support the hypothesis that various vaccination regimens can polarise adaptive immunity towards effective control of cancer-cell growth. However, the exploratory nature of clinical studies done thus far does not allow any cancer vaccine to be used as standard treatment for haematological malignant disorders. Because the cause of disease recurrence is the presence of minimal residual disease after conventional treatments, the adjuvant setting might be the most appropriate therapeutic strategy for active specific immunotherapy, when the immunosuppressive effects of bulky disease are virtually absent and when the effector-target ratio is favourable. In the near future, completion of randomised phase III trials as well as clinical implementation of the most recent insights into tumour immunology that aim to overcome immune tolerance towards malignant cells should allow investigators to define the actual role of vaccines in the management of haematological tumours. [Copyright &y& Elsevier]

The synthesis of a Zn(ii)-phthalocyanine derivative bearing four 10B-enriched o-carboranyl units (10B-ZnB4Pc) and its natural isotopic abundance analogue (ZnB4Pc) in the peripheral positions of the tetraazaisoindole macrocycle is presented. The photophysical properties of ZnB4Pc, as tested against model biological systems, were found to be similar with those typical of other photodynamically active porphyrin-type photosensitisers, including a singlet oxygen quantum yield of 0.67. The carboranyl-carrying phthalocyanine was efficiently accumulated by B16F1 melanotic melanoma cells in vitro, appeared to be partitioned in at least some subcellular organelles and, upon red light irradiation, induced extensive cell mortality. Moreover, ZnB4Pc, once i.v.-injected to C57BL/6 mice bearing a subcutaneously transplanted pigmented melanoma, photosensitised an important tumour response, provided that the irradiation at 600-700 nm was performed 3 h after the phthalocyanine administration, when appreciable concentrations of ZnB4Pc were still present in the serum. Analogously, irradiation of the 10B-ZnB4Pc-loaded pigmented melanoma with thermal neutrons 24 h after injection led to a 4 day delay in tumour growth as compared with control untreated mice. These results open the possibility to use one chemical compound as both a photosensitising and a radiosensitising agent for the treatment of tumours by the combined application of photodynamic therapy and boron neutron capture therapy.