Coulter's Anti-CD20 Therapy Shows Promise

Coulter Corp, which has recently made a foray into therapeutics after many years as a leading diagnostics and instruments company, has published encouraging Phase II results with 131I-B1, an antibody-based therapy for B cell lymphomas.

The new study, published in The Lancet (August 5), involved 25 patients with relapsed B cell lymphomas. The patients were treated with the 131I-labelled anti-CD20 antibody, and 21 of them achieved distributions of the antibody which were higher in the tumor sites than other organs, and therefore received therapeutic doses of the antibody. 18 of these 21 patients had objective responses, including 16 complete remissions, noted the authors.

This trial of a radiotherapeutic antibody approach to a hematological malignancy is interesting because unlike many other studies of this type the treatment was given at myeloablative doses, in conjunction with autologous stem cell rescue. Analysing the data from this trial and from an earlier Phase I study, the authors note that 131I-B1 treatment seems to confer a progression-free survival of 62% and an overall survival of 93% over a median follow-up of two years. In addition, the toxicities of the therapy are modest, compared with total bone marrow irradiation and BM transplant approaches.