Identifying Causes of Unscheduled Healthcare Interactions and Changes to Patient Disposition in Individuals Receiving Outpatient Commercial Bispecific Antibody Therapy in Relapsed/Refractory Multiple Myeloma (RRMM)

Introduction: Teclistamab is a BCMA targeting bispecific antibody that was FDA approved for treating relapsed/refractory multiple myeloma (RRMM) based off the results of the MajesTEC-1 trial (Usmani S, et al. Lancet 2021, Moreau P, et al. N Engl J Med 2022), and is the first bispecific antibody approved for myeloma treatment. While patients included in the MajesTEC-1 study were monitored closely per trial protocols, little is known about what patient-reported care concerns and education gaps may exist outside of a trial setting with standard of care teclistamab and whether these gaps lead to a high number of unscheduled healthcare interactions.

Methods: We retrospectively analyzed patient reported symptom concerns for commercial teclistamab patients at Memorial Sloan Kettering Cancer Center (MSKCC) via review of the electronic health record for a 4-month observation period following treatment initiation. Patients were included in the study if they had a response to teclistamab (per IMWG criteria), remained on treatment for at least 4 months as of our data cut-off (07/20/2023), and did not have evidence of disease progression during the observation period. Collected data included all unscheduled healthcare visits, including urgent care visits, emergency room visits, and hospital admissions. We also evaluated all outpatient communications, including telephone calls to physicians' offices and messages sent to physicians' offices through MSKCC's online patient portal. The total observation period included the first 4 months of therapy, during which patients were scheduled to receive treatment weekly and be seen by their physicians at regular 4-week intervals.

Results: We identified 52 patients treated with teclistamab at our center as of the data cut-off, 19 of which met our inclusion criteria. Of note, this population had poorer performance status (89% vs 67% ECOG ≥1) and had more heavily pretreated disease (6 vs 5 median prior lines of therapy) when compared to the MajesTEC-1 population, with the majority not being eligible for MajesTEC-1 per its criteria. Within this population, 79% of patients communicated with their physicians' offices outside of their scheduled monthly appointments, with an average of 2.3 (0-8) communications sent per patient during the 4-month observation period. The most common reason for communication was upper respiratory tract infection (URI) symptoms, accounting for 24% of all communications. Other notable reasons included gastrointestinal (GI) symptoms (20%), disease related pain (13%), injection site reactions (9%) and symptoms of volume overload (9%). Unscheduled visits included 8 urgent care (UC) visits, and 20 emergency department (ED) visits involving 11/19 patients. The 20 ED visits led to 16 inpatient admissions, not including planned admissions for step-up dosing (data summarized in Figure 1), with a median length of stay of 4 days (2-24 days). URI symptoms triggered 50% of UC visits and 40% of the ED visits not leading to inpatient admission, but only accounted for 6% of hospital admissions. The most common cause of hospital admission was a non-URI acute infection (29%).

Conclusions: Our data suggest that RRMM patients being treated with outpatient teclistamab have frequent unscheduled healthcare interactions. The high prevalence of URIs in our population indicates that infection rates in this frequently hypogammaglobulinemic patient population may be underreported. However, these do not frequently lead to inpatient admissions or to significant morbidity/mortality. Overall, teclistamab patients would likely benefit from improved patient education with regards to expected side effects of therapy, with pre-existing management plans in place for URIs, GI symptoms, and injection site reactions. Applying these principles may limit excessive healthcare visits for patients, particularly in those with heavily relapsed/refractory myeloma with poor disease prognosis. Data from additional patients, including patients receiving step-up dosing as outpatients as part of a pilot study, will be presented at the meeting.