Prophylactic Dexamethasone and Remote Monitoring for Patients with Relapsed Refractory Multiple Myeloma (RRMM) Receiving Bispecific Antibodies (BsAb): Experience at a Single Institution

Background: A challenge in administering BsAb is the step-up dosing (SUD) and careful monitoring required for signs and symptoms of cytokine release syndrome (CRS). Levine Cancer Institute has launched a care quality improvement initiative to explore the feasibility of giving BsAb SUD in an outpatient setting with support from our Hospital at Home (HaH) program. Herein, we describe our experience using this remote monitoring program as well as strategic prophylactic dexamethasone to mitigate the incidence and severity of CRS. Methods: HaH is an established program equipped with a home monitoring kit that includes a blood pressure cuff, pulse oximeter and thermometer. Patients recorded vital signs every 4 hours while awake or when feeling unwell and inputted them into an electronic tablet for the HaH team to review. Patients had in-person visits from a paramedic on the days between infusions in conjunction with a video visit with a HaH internist. The paramedics conducted the Immune Effector Cell Encephalopathy Score and provided oxygen, medications and/or intravenous fluids if necessary. A nurse was available 24/7 via electronic tablet to provide guidance to the patient. Patients took prophylactic dexamethasone 8mg on the day after each SUD to mitigate high-grade CRS. Patients could take acetaminophen or additional doses of Dex for breakthrough fever at the discretion of HaH or the primary oncologist. To be eligible, patients had to have a 24h caregiver, needed to reside within 1 hour from the hospital, could not have rapidly progressive disease or significant tumor burden, an eGFR <40 mL/min/1.73m2 or an absolute neutrophil count <1000. Demographic and clinical characteristics of all patients were reported via descriptive statistics. Continuous variables were reported as medians and ranges, while categorical variables were reported as frequencies and percentages. Results: Eighteen patients were included in this analysis of whom 10 received Teclistamab and 8 received Talquetamab. Seventy-two percent were male, and 22.2% were African American. The median age was 72.5 (range 56-83). Of the evaluable patients, 43.75% had ISS stage III disease and 58.8% harbored high-risk cytogenetics. The median number of prior lines of therapy was 5 (range 4-9). Eleven patients developed CRS, 7 of which were grade 1 and were managed entirely as an outpatient. Four patients developed grade 2 CRS requiring admission, of which 3 were administered a single dose of Tocilizumab. All 4 patients completed subsequent SUDs as an outpatient. The incidence of CRS was highest following earlier SUDs; only 1 patient developed CRS after SUD #3 and SUD#4 for Teclistamab and Talquetamab, respectively. Of the 11 patients who developed CRS, 89% had a single event. There were no ICANS or high-grade CRS. The median duration of CRS was 1 day (range 1-3). Four patients had dose delays due to ongoing CRS. During the follow up period, 2 patients visited the emergency room for concerns unrelated to CRS and 8 patients required admission: 4 for CRS management, 2 for CRS observation, and 2 for unrelated symptoms. The median number of days in the hospital across all admissions was 3 (range 1-6). Additional dex did lead to expected toxicities: hyperglycemia in 4 patients, hypertension in 3 patients and insomnia in 1 patient, all managed by the HaH program. Conclusions: If traditional SUD observation strategies had been used in this cohort, a total of 116 days in the hospital would have been recorded rather than the 19 days under the HaH program. A remote monitoring program can be safely implemented in a selected population of RRMM patients with few admissions for CRS. Prophylactic dexamethasone may mitigate the risk of high-grade CRS though precautions may need to be taken in patients with certain comorbidities.