Successful Outpatient Administration of Blinatumomab Infusion in Pediatric Patients with Acute Lymphoblastic Leukemia

Introduction:

Acute lymphoblastic leukemia (ALL) is the most common type of pediatric cancer. Unfortunately, approximately 15% of children with high-risk B-cell ALL (B-ALL) relapse after frontline chemotherapy. Treatment of relapsed/refractory B-ALL is still challenging, and more effective novel therapies are urgently warranted. Blinatumomab, a first in class bispecific antibody therapeutic, has demonstrated superiority compared to standard chemotherapy in patients with B-ALL and has a manageable toxicity profile. Blinatumomab functions by binding to CD19 expressed on B-cells and CD3 expressed on T-cells, resulting in T-cell-mediated killing of CD19-positive cells common in B-cell malignancies.

Despite remarkable efficacy and a manageable toxicity profile compared to standard-of-care chemotherapy, blinatumomab poses unique healthcare system challenges related to preparation, administration, toxicity monitoring, and medication error prevention. The drug's success in helping patients achieve complete remission relies on its continuous and uninterrupted administration. In order to ensure that it is delivered in the safest and most effective manner, education on its unique logistical and administration challenges is imperative.

Objectives:

The primary objective of this study is to describe and share the 6 years of institutional experience on the outpatient delivery of blinatumomab for the management of pediatric patients with B-ALL as per Children's Oncology Group protocols, as well as to retrospectively analyze the safety of this novel 28-day home-based therapy.

Methods:

A multidisciplinary team composed of physicians, nurses, and pharmacists was created to address administration challenges associated with blinatumomab infusions. Although blinatumomab requires a 28-day continuous infusion, it is not necessary for patients to remain hospitalized for the entire cycle. To ensure tolerability prior to discharge, patients are monitored closely during the first 3 days of Cycle 1 and 2 days of Cycle 2 for signs of cytokine release syndrome and neurological toxicities. Once discharged, they are seen every 96/72 hours for bag changes in either an outpatient hematology/oncology unit or by home health for those off study.

Results:

A total of 16 patients were treated with blinatumomab between May 2015 and June 2021; 10 were newly diagnosed and 6 were in first relapse. Of the 26 total infusions, 24 were successfully completed without significant adverse reactions. Two patients treated for relapsed disease had to discontinue therapy; one experienced neurotoxicity within 72 hours of blinatumomab infusion initiation and the other developed refractory disease and was switched to another protocol. No adverse events were observed in the home setting.

Discussion:

The team was successfully able to transform the original inpatient-only blinatumomab protocol to the outpatient setting. Retrospective analysis over 6 years demonstrates a clinically significant reduced rate of complications of blinatumomab administration in comparison to previous reports (Amicucci et al. 2021), which can be attributed to careful multidisciplinary team planning and delivery. This study confirms the feasibility of a home-based continuous blinatumomab infusion without adverse effects on safety. Additionally, this outpatient protocol leads to cost savings associated with reduced length of stay and an overall improved quality of life for pediatric patients able to receive therapy at home with their caregivers.