Safety and Effectiveness of A-dmDT390-bisFv(UCHT1) Fusion Protein in Subjects With Mycosis Fungoides

Inclusion Criteria: * Subjects must have signed the current IRB approved informed consent prior to registration (see Informed Consent). * Mycosis fungoides, confirmed by biopsy or flow cytometry, without large cell transformation. * Relapse or progression after 2 or more systemic therapies. Note: Total electron beam therapy can be counted as a systemic therapy. * Disease stage as follows: * Stage IB with no lymph node involvement including lymphadenopathy with mSWAT \<50; * Stage IIB with no lymph node involvement including lymphadenopathy with mSWAT \<50. * Age 18 years. * Subjects must have a performance status of \< 2 on Eastern Cooperative Oncology Group scale (see Appendix A). * Subjects must have normal lung function evaluated by pulse oximetry with O2 saturation values between 95-100%. * Subjects must have fully recovered from toxicity of prior chemotherapy or radiation therapy. * Subjects must have: * bilirubin \< 1.5 mg/dL, * transaminases \< 2.5 X ULN, * albumin \> 3 gm/dL, * creatinine \< 2.0 mg/dL. * Subjects who have had albumin \< 3 gm/dL boosted by an albumin infusion must be observed to maintain albumin at \> 3gm dL for 14 days without an additional infusion. * Subjects must have a normal echocardiogram (EF \> 50% normal) without any evidence of cardiac chamber hypertrophy, dilatation or hypokinesis. * Females and males must be willing to use an approved form of birth control while on this study and for 2 weeks after completion. * Subjects must have a pretreatment anti-DT titer of 20 μg/ml or less. Subjects with titers between 21 and 35 μg/ml will have an additional anti-DT neutralization test using subject's serum and A-dmDT390-bisFv(UCHT1). If neutralization is not found these titers will be considered acceptable. Exclusion Criteria: * Failure to meet any of the criteria. * Inability to give informed consent because of psychiatric problems, or complicated medical problems. * Allergic to diphtheria toxin a component of the study drug A-dmDT390-bisFv(UCHT1). * Serious concurrent medical problems, uncontrolled infections, or disseminated intravascular coagulopathy (DIC), hepatic cirrhosis, or chronic kidney disease. * CNS leukemia. * Preexisting cardiovascular disease. The only exception being well controlled essential hypertension with a sitting blood pressure (B.P.) of \<160 systolic and \<90 diastolic without any evidence of structural heart disease or one episode of myocardial infarction \> 8 months ago. Subjects receiving a beta-blocker for hypertension should be converted to another antihypertensive drug class 2-3 weeks before receiving the study drug to prevent a drug-drug interaction reactive tachycardia. Angiotensin inhibitors, angiotensin receptor blockers and calcium channel blockers are all acceptable. A past history of any of the following conditions is considered as exclusions to study participation: * Congestive heart failure, * Atrial fibrillation, * Pulmonary hypertension, * Anticoagulant drug therapy, * Thromboembolic events, * Cardiomyopathy or a myocardial infarction within the past 8 months. The PI and the Clinical Coordinator will be asked to verify that their referred subjects do not have these exclusionary histories listed in 3.2 and a copy of this verification must be sent to the Sponsor before the Sponsor will approve of enrollment. Referring physicians will not need to sign. * Pregnant or nursing women will be excluded from study. * History of cirrhosis of the liver based on the Child-Pugh score of Class B or C are not eligible to participate. * Prior treatment with alemtuzumab (Campath) or similar agents or procedures that depress blood T cell counts to below 50% of the lower limit of normal. * Prior history of bone marrow transplant or HSCT is an exclusion. * Prior treatment with vorinostat (Prior treatment with vorinostat for lead-in dosing arm is acceptable).