Background:
- CD4+ cells are white blood cells that regulate the immune system by controlling the
strength and quality of the immune response.
- CD25+ cells are a subset of CD4+ cells that suppress or prevent immune responses.
- RFT-5-dgA is an immunotoxin (substance that kills specific cells in the immune system)
that kills CD25+ cells.
- In mouse studies, RFT-5-dgA showed anti-tumor activity in animals studies.
Objective: To determine whether the immune system of patients with metastatic melanoma
(melanoma that has spread beyond the original site) can cause tumors to shrink if the
patients are given RFT-5-dgA to remove their CD25+ cells.
Eligibility: Patients 18 years of age and older with metastatic melanoma whose disease has
progressed after receiving standard treatment.
Design:
- Patients receive RFT-5-dgA through a vein every other day for a total of 3 doses (one
treatment course). Patients have routine blood tests during the week of treatment.
- Four to 5 weeks after the last dose, patients are evaluated with a physical examination,
blood tests and scans and x-rays to evaluate their tumor.
- Patients whose tumor has shrunk or remained stable may be offered additional treatment
with RFT-5-dgA up to a total of four courses.
- Patients undergo leukapheresis or have several tubes of blood drawn from a vein to
determine the effects of RFT-5-dgA on the immune system. This is done before the first
dose of RFT-5-dgA, after the first three doses, and possibly during subsequent treatment
courses in those patients who receive additional treatment. For leukapheresis, blood is
collected through a needle in an arm vein and flows through a catheter into a machine
that separates it into its components by spinning. The white cells are extracted and the
rest of the blood is returned through another needle in the other arm.