The Food and Drug Administration (FDA) has approved moxetumomab pasudotox-tdfk (Lumoxiti), a CD22-directed cytotoxin, to treat hairy cell leukemia (HCL).
Moxetumomab pasudotox is approved to treat adults with relapsed or refractory HCL who have received at least two prior systemic therapies, including treatment with a purine nucleoside analog.
The prescribing information for moxetumomab pasudotox includes a boxed warning noting that the drug poses risks of capillary leak syndrome and hemolytic uremic syndrome. Other serious warnings include the risk of decreased renal function, infusion-related reactions, and electrolyte abnormalities.
The FDA granted the application for moxetumomab pasudotox fast track, priority review, and an orphan drug designation.
The agency approved AstraZeneca’s moxetumomab pasudotox based on results from a phase 3 trial (NCT01829711). Data from this study were presented at the 2018 annual meeting of the American Society of Clinical Oncology (abstract 7004).
The trial included 80 patients with relapsed or refractory HCL who had received at least two prior lines of therapy.
At a median of 16.7 months of follow-up, the objective response rate was 75%, the complete response (CR) rate was 41%, and the durable CR rate was 30%. Durable CR was defined as CR with hematologic remission for more than 180 days.
Most patients with a CR achieved minimal residual disease negativity (82%; 27/33).
The median duration of response was not reached, nor was the median progression-free survival.
The most common treatment-related adverse events (AEs) were nausea, peripheral edema, headache, and pyrexia. Other treatment-related AEs included infections and neutropenia.
Treatment-related AEs that led to discontinuation included capillary leak syndrome, hemolytic uremic syndrome, and increased blood creatinine.
There were three deaths in this trial, but none of them were considered treatment related.