Moxetumomab Pasudotox-tdfk (Lumoxiti(TM)) and Either Rituximab (Rituxan(R)) or Ruxience for Relapsed Hairy Cell Leukemia

Description

Background:

* Hairy cell leukemia (HCL) is an indolent cluster of differentiation-22 (CD22+) B-cell leukemia comprising 2% of all leukemias, or approximately 1200 of the 62,130 new cases of leukemia/year in the United States (US). HCL variant (HCLv), also CD22+, is 10-20% as common as HCL, but more common in the relapsed/refractory population due to its poor prognosis and response to standard purine analog chemotherapy. hairy cell leukemia variant (HCL-V) cells are cluster of Differentiation 25 (CD25)-negative and wild type for BRAF, so HCLv patients are not candidates for BRAF inhibitors. CD25+ classic-appearing HCL-cells that express unmutated IGHV4-34 (Immunoglobulin Heavy Variable 4-34) are wild-type for BRAF, remain brightly CD22 positive, and confer a poor prognosis when treated with chemotherapy.
* Moxetumomab pasudotox-tdfk is a recombinant immunotoxin containing a variable domain (Fv) fragment of an anti-CD22 monoclonal antibody and truncated Pseudomonas exotoxin, which kills CD22+ cells by binding to CD22 via the (Fv) fragment, and induction of apoptotic cell death catalytic inhibition of protein synthesis in the cytosol.
* Moxetumomab pasudotox-tdfk in phase 1 testing demonstrated a high complete response (CR) rate in patients with chemoresistant HCL, without dose-limiting toxicity (DLT), but with reversible grade 2 hemolytic uremic syndrome (HUS) not requiring plasmapheresis.
* Moxetumomab pasudotox-tdfk completed multicenter phase 3 testing in 80 patients, meeting its complete response (CR) endpoint, with 8.8% incidence each of capillary leak syndrome (CLS, grade 3-4 2.5%), and HUS (grade 3-4 6.3%), both reversible.
* Moxetumomab pasudotox-tdfk is the only known non-chemotherapy-containing regimen for HCL which can consistently eradicate minimal residual disease (MRD), and this is associated with prolonged CR durations. Recently, US Food and Drug Administration (FDA) has accepted the Biologics License Application (BLA) for moxetumomab pasudotox-tdfk as the treatment of adult patients with HCL.
* Patients who did not achieve CR, or CR with MRD, often made neutralizing antibodies to the bacterial-based toxin, and/or had collections of HCL cells not completely eradicated by Moxetumomab pasudotox-tdfk. Both issues may be addressed by the addition of anti-cluster of differentiation 20 (CD20) monoclonal antibody (Mab) rituximab or Ruxience to Moxetumomab pasudotox-tdfk.

Objective:

-To determine the safety and toxicity of Moxetumomab pasudotox-tdfk and rituximab/Ruxience used at the planned dose level, in patients with HCL and HCLv.

Eligibility:

* HCL or HCLv with at least 1 prior purine analog, and, for HCL patients with >=2-years 1 month response, at least 1 other therapy.
* Need for treatment, either 1) absolute neutrophil count (ANC) <1/nL, 2) hemoglobin (Hgb) <10g/dL, 3) platelet (Plt) 2cm in short axis
* Serum creatinine 3 hours without drinking from days 1 to 8 and to keep a hydration diary to record daily fluid consumption.
* To prevent rituximab/Ruxience toxicity, patients will receive prophylactic dexamethasone orally 0.5- 2 hours before the 1st dose of rituximab, and before subsequent doses until rituximab/Ruxience infusion reactions are not seen. Patients will also receive diphenhydramine, famotidine, and acetaminophen.
* Dexamethasone 4 mg orally (maximum 2 doses/day) will be given as needed to treat nausea or fever associated with Moxetumomab pasudotox-tdfk, which might prevent adequate water intake
* Statistical design:

* Up to 26 patients are intended to be treated in the trial. While a total of 26 evaluable patients will be enrolled, the accrual ceiling will be set at 30 to include screen failures and inevaluable patients.