Real-World Treatment Outcomes of Teclistamab Under an Outpatient Model for Step-up Dosing Administration
Authors: Sandahl Tyler B. , Soefje Scott A. , Calay Ediz S. , Lin Yi , Fonseca Rafael , Ailawadhi Sikander , Parrondo Ricardo , Lin Dee , Wu Bingcao , Silvert Eli , Kim Nina , Carpenter Corinne , Wagner Tyler E. , Fowler Jessica , Hester Laura , Marshall Alexander , Stoy Patrick , Gifkins Dina , Kumar Shaji Kunnathu 
Published: December 2023

Background
Teclistamab, the first-in-class B-cell maturation antigen (BCMA) x CD3 bispecific therapy was recently approved by the FDA for the treatment of triple-class exposed relapsed or refractory multiple myeloma (MM) after ≥ 4 prior lines of therapy. Because of the risk of cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS), the step-up dosing (SUD) of teclistamab is commonly administered in an inpatient setting among early users. Mayo Clinic has a well-established hospital-based outpatient program for novel immunotherapies. Since the FDA approval, teclistamab SUD has been administered as part of this program. Each dose of the SUD is administered in an outpatient setting, and the patient is given a remote monitoring kit to regularly measure vital signs and stay connected with the command center for signs and symptoms of CRS and ICANS throughout the entire SUD period. This study aimed to evaluate early safety outcomes and healthcare resource utilization during SUD in real-world (RW) patients who initiated teclistamab under the outpatient administration model across 3 Mayo Clinic locations (Rochester, MN, Phoenix/Scottsdale, AZ, Jacksonville, FL).
Methods
This was a retrospective study using Mayo Clinic's electronic medical records from October 26, 2022 to June 12, 2023. Eligible patients were adults diagnosed with MM who had initiated commercial teclistamab at any of the 3 Mayo Clinic locations. Patient characteristics, rates and severity of CRS and ICANS, as well as healthcare resource utilization during SUD were described. Time between teclistamab administration and patient check-out was reported for SUD and treatment doses, respectively.
Results
At the time of data cutoff, 39 patients received at least 1 teclistamab dose across the 3 locations (median age 67.2 years; male: 74%; White: 87%; non-Hispanic: 92%), including 36 patients who initiated teclistamab SUD directly in an outpatient setting. A total of 8 (21%) patients had MM with high-risk cytogenetics and 14 (36%) had prior exposure to other BCMA-targeted therapies. Prevalent comorbidities prior to receiving teclistamab included anemia (77%), hypertension (56%), lytic bone lesions (51%), neutropenia (49%), and hypogammaglobulinemia (41%). Renal impairment or failure was observed in 31% of the patients (Table 1).
Almost all patients received acetaminophen (95%), diphenhydramine (95%), and dexamethasone (92%) as pre-medications on the same day as teclistamab administrations during SUD. Of the teclistamab doses with clinic time data, the majority (62%) of doses during SUD required 30 minutes to 1 hour of clinic time for monitoring between administration and check-out. After SUD, the clinic time for weekly treatment doses decreased to less than 30 minutes for most (79%) doses (Figure 1). In patients who completed SUD by data cutoff (n = 37), most patients (70%) received the SUD on a 3-day dose interval (i.e., day 1, 4, 7). The mean time between the first and third doses was 6.3 days.
Among the 37 patients with complete SUD, 12 (32%) developed CRS. The highest CRS grade was grade 1 for 10 patients; 1 patient had a grade 2 CRS, and 1 patient had a grade 4 CRS. The patient with grade 4 CRS concurrently decompensated during a dialysis session and all symptoms were considered for CRS grading. A total of 6 patients had recurrent CRS, including 1 patient with 3 events during SUD. All patients who developed CRS during SUD (n=12) were admitted to the hospital for treatment, with a total of 19 admissions across all patients and a median length of stay of 1.7 days per admission. Among patients who were admitted for CRS (n=12), the majority were treated with acetaminophen (92%), diphenhydramine (83%) and dexamethasone (83%); tocilizumab was given to the 2 patients with CRS grade 2 or higher. Only 1 ICANS event (grade 2) was observed in 1 patient during SUD, after dose 3, and the patient was admitted to the hospital for treatment.
Conclusion
This study evaluated early RW safety outcomes of teclistamab under an outpatient administration model and found the CRS rate and severity to be comparable with other RW evidence generated from various data sources. Outcomes related to teclistamab SUD from Mayo Clinic supported the safety and feasibility of outpatient administration model as a potential option to reduce healthcare resource utilization and improve treatment experiences.