SS1P + cyclophosphamide + pentostatin

SS1P + cyclophosphamide + pentostatin is a combination therapy used in the treatment of advanced refractory malignant mesothelioma. SS1P is a recombinant immunotoxin composed of an anti-mesothelin dsFv (SS1 Fv) fused to a 38 kDa Pseudomonas exotoxin-A fragment (PE38). This combination therapy uses cyclophosphamide and pentostatin as T- and B-lymphocyte-depleting immunosuppressive treatments administered before and concurrent with SS1P. This approach has been shown to markedly delay the development of neutralizing antibodies against SS1P, which is a common limitation in SS1P monotherapy where the majority of patients develop neutralizing antibodies after the first treatment cycle. The immunosuppression allows for more treatment cycles of SS1P to be administered.