A phase-I study of an anti-CD25 ricin A-chain immunotoxin (RFT5-SMPT-dgA) in patients with refractory Hodgkin's lymphoma.

The anti-CD25 immunotoxin (IT), RFT5-SMPT-dgA, was used in a phase I dose escalation trial in patients with refractory Hodgkin's lymphoma. The IT was constructed by linking the monoclonal antibody RFT5 via a sterically hindered disulfide linker to deglycosylated ricin-A. All patients in this trial were heavily pretreated with a mean of 5 (range, 2 to 8) different prior therapies, including autologous bone marrow transplantation in 8 of 15.