Sandahl, Tyler B.

PURPOSE Daratumumab is an anti-CD38 monoclonal antibody used to treat multiple myeloma and light chain amyloidosis. Because daratumumab may cause reactions after intravenous or subcutaneous (SC) administration, the manufacturer labeling recommends administration of premedications before every dose. Given incidence of infusion reactions appears to be rare after cycle 1, in April 2022, the Mayo Clinic implemented a practice change in which premedications were omitted from all daratumumab order sets after completion of cycle 1. This study investigated the safety of this practice. METHODS A retrospective chart review at the Mayo Clinic reviewed eligible patients with multiple myeloma or amyloid light-chain (AL) amyloidosis who received their first dose of daratumumab within the 4 months preceding the date of implementation (preimplementation group) or no more than 4 months after (postimplementation group) the date of implementation on April 13, 2022. Data were collected only from the first eight once per week doses of daratumumab. The primary outcome was the incidence of infusion-related reactions. Data analyzed used descriptive statistics. RESULTS Nearly all patients (95.9%) received daratumumab by SC route of administration. Of the 97 patients in the preimplementation group, >90% received premedications throughout cycles 1 and 2, and five patients (5.2%) experienced infusion reactions. Of 72 patients in the postimplementation group, <20% received premedications during cycle 2 and three patients (4.2%) experienced infusion reactions. All infusion reactions occurred within the first daratumumab cycle, indicating elimination of cycle 2 premedications did not cause any infusion reactions. No patient experienced more than one infusion reaction. CONCLUSION Omission of premedications after cycle 1 of daratumumab did not increase the incidence of infusion. Premedications may safely be omitted after cycle 1 of daratumumab when administered by the SC route.

Background: Skeletal related events (SREs) including pathologic fractures, surgery or radiation to bone, and spinal cord compression contribute to diminished quality of life in patients with multiple myeloma. Bone modifying agents (BMA) such as denosumab or the bisphosphonates zoledronic acid and pamidronate, are used to inhibit osteoclast activity to prevent SREs. The Bone Working Group of the International Myeloma Working Group suggests monthly administration of zoledronic acid for 12 months in newly diagnosed myeloma patients. This is followed by an option to discontinue or decrease administration frequency to every 3, 6, or 12 months if a very good partial response or better is achieved. The ideal start time of BMA from diagnosis and the duration of administration has not been adequately established to optimize reduction of SREs. Methods: This was a retrospective, single-center study that included newly diagnosed myeloma patients treated at the Mayo Clinic between 9/1/2018 and 9/1/2020 who had received at least one dose of a BMA. The primary objective was to evaluate the impact of BMA dosing frequency and duration on SREs. Secondary objectives included time to BMA initiation, time to relapse or progressions following BMA start, and safety. Data was summarized using frequencies and percentages for categorical data, and medians and interquartile ranges (IQR) for continuous data. A spline plot and cut-point analysis were used to assess the association of time from multiple myeloma diagnosis to BMA initiation with skeletal related outcomes. Rates of SREs were estimated using the Aalen-Johansen method, where death was treated as a competing risk. Associations of factors with SREs were assessed using Cox proportional hazards regressions, and these associations were summarized using hazard ratios (HR) and corresponding 95% confidence intervals (CI). Variables that could change throughout follow-up including BMA frequency, cumulative BMA dose, and duration of BMA were treated as time-dependent covariates in the Cox proportional hazards models, where the information for these variables was updated each time an additional dose of BMA was given. All analyses were performed using SAS version 9.4 software (SAS Institute, Inc.; Cary, NC) and R version 4.2.2 (R Core Team, R Foundation for Statistical Computing, Vienna, Austria). Results: Sixty-seven patients were included with a median age of 65 years old. The most frequently used BMA was zoledronic acid (88.1%), followed by pamidronate (7.5%), and denosumab (4.5%). Fifty-five patients (82.1%) had bone disease at baseline. Within 2 years of starting BMA, SREs occurred in 42.2% of patients with baseline bone disease and 8.3% of patients without (p=0.054). Median time to BMA initiation after diagnosis was 45 days (IQR 14-105) in patients with baseline bone disease and 87 (IQR 32-496) in patients without. Among the 26 patients with a SRE, median time from start of BMA to SRE was 170 days (IQR 32-496). No significant association was found between time to initiation and development of a SRE (Figure 1). BMA dosing frequencies of every 3 months and 6 months had a HR for SREs of 1.67 and 0.47, respectively compared to every 1 month, (P-values &gt;0.25). After excluding patients without baseline bone disease, compared to every 1 month dosing, dosing every 3 months and every 6 months increased the risk of SRE, although the differences were not statistically significant (3 months: HR=1.92, 95% CI 0.76-4.88, p=0.17; and 6 months: HR=1.26, 95% CI 0.14-10.94, p=0.84). Patients without bone disease at baseline remained on BMAs for a median of 1.8 years while patients with bone disease received BMAs for a median of 2 years. There was no statistically significant difference found with varying duration or cumulative dose and SRE development (Table 1). Relapse or progression occurred in 32.1% of patients within 2 years of starting BMA, while death occurred in 7.5% of patients. Osteonecrosis of the jaw occurred in 1 patient with bone disease at baseline who received zoledronic acid every 3 months for a duration of 596 days. Conclusions: No significant association between time of BMA initiation, dosing frequency, or duration on development of SREs were observed. This suggests delaying the start time of BMAs to allow for dental clearance and initial treatment would not increase risk of SREs. Prospective trials are needed to confirm these findings.

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.