Subcutaneous Administration of Daratumumab Reduces Time in Clinic Vs Intravenous Treatment

Patients with multiple myeloma who received subcutaneous daratumumab (Darzalex) experienced reduced clinic times compared with those who received the agent intravenously, potentially freeing up clinic resources, according to findings from a retrospective study published in in JCO Oncology Practice.¹

Results from the study showed that patients who were treated with intravenous daratumumab (n = 587) experienced a median total clinic time of 4.8 hours. Comparatively, patients who received subcutaneous daratumumab (Darzalex Faspro; n = 215) experienced a shorter median total clinic time with a 2.9-hour reduction. Shortened median clinic times were also observed among patients who initially received the agent intravenously before switching to subcutaneous administration (n = 80), with a reduction in median clinic time of 3.0 hours.

To conduct their study, investigators extracted data from the electronic health record database of the Mayo Clinic. Patients were identified from 13 Mayo Clinic sites for inclusion in their analysis. The date range examined spanned from April 5, 2017, to October 14, 2021.

Total clinic time was defined as the difference between the time at patient check-in and check-out. Total chair time was calculated from infusion room entry to infusion room exit or check-out, whichever occurred earlier, and accounted for order review, pharmacy preparation, and postadministration observation. The time from the end of daratumumab administration to infusion room exit or patient check-out represented postadministration observation time.

Using software from the biotechnology company nference, the database was curated to analyze aspects of clinical practice related to the subcutaneous and intravenous administration of daratumumab. Patients were included in the study if they were aged at least 18 years when they received their first daratumumab treatment outside of an interventional clinical trial, had an International Classification of Diseases (ICD) ninth or tenth revision code of MM, and had record availability of medications administered. Investigators also noted prescription orders, appointment times, and total daratumumab administration time. Additionally, administration-related reaction (ARR) events were identified.

A 4-hour observation period designed to monitor for ARRs was incorporated into the Mayo Clinic treatment plan following the first subcutaneous administration of daratumumab and for 1 hour after additional doses. The treatment plan for subcutaneous daratumumab was modified to shorten the mandated postadministration observation time from 4 to 2 hours for dose 1 and from 1 hour to 30 minutes for doses 2 and 3, on May 3, 2021. If an ARR was reported, the observation time of the following dose was 4 hours.

Findings related to 3 categories of ARR-related events occurring withing 72-hours following daratumumab treatment were captured:administration of known medications for ARR management after initiation of a daratumumab subcutaneous administration, entry of ICD codes associated with ARR-related symptoms not reported before daratumumab therapy began, and admission to an emergency department or hospitalization within the Mayo Clinic system. Additionally, investigators recorded preadministration medications spanning the date of the visit until the start time of daratumumab treatment. Postadministration medications were also accounted for from the start of daratumumab treatment until 72-hours following administration.

In light of the May 3, 2021, modification, data pertaining to the subgroups of patients treated under the initial Mayo Clinic treatment plan for subcutaneous daratumumab (n = 144) and those treated after the treatment plan amendment with shortened observation times (n = 71) were also tracked.

Baseline patient demographics were generally well balanced between the intravenous, subcutaneous, intravenous to subcutaneous, initial subcutaneous plan, and shortened subcutaneous plan groups. The median age was 70.0 years (IQR, 62.5-76.0), 70.0 years (IQR, 62.5-76.0), 67.5 years (IQR, 59.8-74.0), 70.0 years (IQR, 62.8-76.0), and 70.0 years (IQR, 62.5-76.5), respectively. Most patients in each group were men (61.8% vs 63.3% vs 72.5% vs 63.9% 62.0%) and White (90.1% vs 91.6% vs 82.5% vs 89.6% vs 95.8%).

Additional findings from the study showed that patients in the subcutaneous initial plan and subcutaneous shortened plan also experienced shortened median clinic times compared with those who received daratumumab intravenously, with respective decreases of 2.9 hours and 2.7 hours, respectively. The median total chair time for patients who received intravenous daratumumab was 4.0 hours. Patients in the subcutaneous, intravenous to subcutaneous, initial subcutaneous plan, and shortened subcutaneous plan groups all experienced reductions in median chair time compared with the intravenous group, with respective median times of 1.3 hours, 1.2 hours, 1.3 hours, and 1.3 hours.

In terms of preadministration medication, use was mostly higher than that of postadministration medication across subgroups and doses. Overall, fewer patients in the subcutaneous cohorts were treated with postadministration medications compared with patients who received intravenous daratumumab.

Regarding ARR events, patients treated at dose 1 experienced an event at a rate of 8.8% and 5.0% in the subcutaneous and intravenous to subcutaneous groups, respectively. In the subcutaneous group, ARR-related events occurring at dose 1 consisted of medications (8.4%), ICD codes (0.5%), and emergency department admission/hospitalization (0.9%). In the intravenous to subcutaneous subgroup, these rates were 5.0%, 1.3%, and 0%, respectively.

References

Soefje SA, Carpenter C, Carlson K, et al. Clinical administration characteristics of subcutaneous and intravenous administration of daratumumab in patients with multiple myeloma at Mayo Clinic infusion centers. JCO Oncology Practice. Published online February 9, 2023. doi:10.1200/OP.22.00421