Therapy Targeting the Interleukin-3 Receptor (IL3R) for Patients with Relapsed or Refractory and Elderly Blastic Plasmacytoid Dendritic Cell Neoplasm (BPDCN) with DT388IL3 (SL-401) (IND# 11314): a Phase IB Clinical Trial


This is a phase iB study designed to determine the safe dose of DT388iL3/SL-401 (as defined in Schema iV) for the treatment of patients with Blastic Plasmacytoid Dendritic Cell neoplasm (BPDCn). From this point on assuming no dose limiting toxicity (DLT) occurs, the dose will be administered to five patients. if two patients enrolled at the 12.5[MiCRo-SYMBoL]g/kg dose level experience DLT, the MTD has been exceeded and additional patients will be treated at the next lower dose level 10 same[MiCRo-SYMBoL]g/kg. if two patients experience DLT, the MTD has been exceeded, and the study will be halted.

Patients will be treated with a maximum of five doses of approximately 15min iV infusions of DT388iL3/SL-401 over a ten day period at a maximum of once daily.

Response to Treatment will be evaluated as follows:
1. Complete response (CR): patient has a normal whole blood count; platelets with absent blasts in peripheral blood or marrow; no evidence of nodal involvement or liver/spleen involvement; no skin lesion involvement.

2. Partial Response (PR); patient experiences a decrease of 50% or more in marrow blasts and skin lesions there is a decrease in the size of the nodes/liver/spleen.

3. Stable Disease (SD); failure to achieve at least PR, and there is no evidence of progression for 2 months.

4. Failure: death during treatment or disease progression characterized by an increase in the percentage bone marrow blast or an increase in skin or node/liver or spleen size.

Participant Eligibility

1. All patients must be informed about the study and signed informed consent.

2. All patients must have blastic plasmacytoid dendritic neoplasm (BPDCN) diagnosed by morphologic, histochemical and cell surface marker criteria.

3. All patients must have failed or be intolerant of chemotherapy and allogeneic stem cell transplantation.

4. Patients must have a performance status of <= 2 on the ECOG scale

5. Patients must have bilirubin <=1.5 mg/dl, transaminases <2.5x upper limit of normal, albumin >=3gm/dl, creatinine <=1.5mg/dl, and adequate cardiac reserve (EF>=50%).

6. Must give written informed consent.

7. Must be willing to be treated at the University of Texas Southwestern Hospital and clinics.

8. Females and males must be willing to use an approved form of birth control while on this study and for 2 weeks after completion.

9. Age >= 18 years.