Phase III 1053 trial of CAT 8015 meets primary endpoint of complete response in hairy cell leukaemia.- AstraZeneca + MedImmune.

AstraZeneca and MedImmune presented results from the Phase III 1053 clinical trial that evaluated CAT 8015 (moxetumomab pasudotox) in 80 patients with relapsed or refractory hairy cell leukaemia (HCL) who had received at least two prior lines of therapy. Moxetumomab pasudotox, an investigational anti-CD22 recombinant immunotoxin, showed a 75% objective response (OR) rate, a 41% complete response (CR) rate, and a 30% durable CR rate (primary endpoint). The majority of patients with a complete response had a durable response (73%; 24/33) and achieved a negative minimal residual disease (MRD) status (82%; 27/33).

The most frequent treatment-related adverse events (AEs) were nausea (28%), peripheral oedema (26%), headache (21%), and pyrexia (20%); 8% had infections and 3% had neutropaenia deemed treatment-related. Three patient deaths occurred, none of which were determined to be treatment-related. Treatment-related AEs leading to discontinuation were haemolytic uraemic syndrome (HUS; 4 [5%]), capillary leak syndrome (CLS; 2 [3%]), and increased blood creatinine (2 [3%]). Seven patients (9%) had CLS and seven (9%) had HUS; this includes four (5%) patients who had both CLS and HUS. CLS and HUS were manageable and reversible. Findings were presented at the 2018 American Society of Clinical Oncology (ASCO) Annual Meeting.

Comment: In April 2018, AstraZeneca announced that the FDA accepted the Biologics License Application (BLA) for moxetumomab pasudotox for the treatment of adult patients with HCL who have received at least two prior lines of therapy. The BLA is based on results from the Phase III �1053� clinical trial. The FDA has granted Priority Review status with a Prescription Drug User Fee Act action date set for the third quarter of 2018.