FDA Approves Moxetumomab Pasudotox-tdfk for Hairy Cell Leukaemia

Approval is based on results from the Study 1053

On 13 September 2018, the U.S. Food and Drug Administration (FDA) approved moxetumomab pasudotox-tdfk (LUMOXITI, AstraZeneca Pharmaceuticals LP), a CD22-directed cytotoxin indicated for adult patients with relapsed or refractory hairy cell leukaemia (HCL) who received at least two prior systemic therapies, including treatment with a purine nucleoside analogue (PNA). 

Approval was based on Study 1053 (NCT01829711) in patients with histologically confirmed HCL or HCL variant requiring treatment based on presence of cytopenias or splenomegaly and who had received prior treatment with at least two systemic therapies, including one PNA. Eligible patients had serum creatinine ≤ 1.5 mg/dL or creatinine clearance ≥ 60 mL/min as estimated by the Cockcroft Gault equation. A total of 80 patients were enrolled; 77 with classic HCL and 3 with HCL variant. Patients received moxetumomab pasudotox-tdfk, 0.04 mg/kg as an intravenous infusion, over 30 minutes on days 1, 3, and 5 of each 28-day cycle for a maximum of 6 cycles or until documentation of complete response (CR), disease progression, or unacceptable toxicity. 

Efficacy in HCL was evaluated by the blinded independent review committee (IRC)-assessed rate of durable CR confirmed by maintenance of haematologic remission (haemoglobin ≥ 11 g/dL, neutrophils ≥ 1500/mm3, and platelets ≥ 100,000/mm3 without transfusions or growth factor for at least 4 weeks) more than 180 days after IRC-assessed CR. The IRC-assessed durable CR rate was 30% (24/80 patients; 95% CI: 20, 41). The IRC-assessed CR rate was 41% (33/80 patients; 95% CI 30,53). 

The most common non-laboratory adverse reactions (≥20%) of any grade were infusion related reactions, oedema, nausea, fatigue, headache, pyrexia, constipation, anaemia, and diarrhoea. The most common grade 3 or 4 adverse reactions (reported in at least ≥ 5% of patients) were hypertension, febrile neutropenia, and haemolytic uremic syndrome (HUS). Adverse reactions resulting in permanent discontinuation of moxetumomab pasudotox-tdfk occurred in 15% (12/80) of patients. The most common adverse reaction leading to discontinuation was HUS (5%). The most common adverse reactions resulting in dose delays, omissions, or interruptions was pyrexia (3.8%). 

The recommended dose of moxetumomab pasudotox-tdfk is 0.04 mg/kg administered as a 30-minute intravenous infusion on days 1, 3, and 5 of each 28-day cycle for a maximum of 6 cycles or until occurrence of disease progression or unacceptable toxicity.

Full prescribing information for LUMOXITI is available here. 

FDA granted this application fast track and priority review designation. Moxetumomab pasudotox-tdfk has also been granted Orphan Drug Designation for the treatment of HCL.

Healthcare professionals should report all serious adverse events suspected to be associated with the use of any medicine and device to FDA’s MedWatch Reporting System.