Daratumumab Split First Versus Single Dosing Schedule Among Patients With Multiple Myeloma Treated in a US Community Oncology Setting: A Retrospective Observational Study

Successful use of split-dose intravenous daratumumab in a multiple myeloma patient after a first-dose life-threatening infusion-related reaction

INTRODUCTION

Daratumumab is a humanized IgG1 kappa monoclonal antibody directed against CD38 used to treat myeloma. The recommended dose of daratumumab is 16 mg/kg, with no lower or upper threshold. Here, we present the first split-dose daratumumab infusion experience in a myeloma patient with morbid obesity in whom daratumumab was interrupted because of grade 3 infusion-related reaction.

CASE REPORT

A female myeloma patient with morbid obesity received a combination of chemotherapy with daratumumab because of disease relapse. The calculated dose for the first intravenous daratumumab infusion was 1840 mg/day based on the weight of the patient, which was measured as 115 kilograms. Daratumumab infusion was initiated as appropriate but needed to be stopped because of a severe sudden presentation of shortness of breath and hypoxemia.

MANAGEMENT AND OUTCOME

After daratumumab was stopped, premedication was repeated, and oxygen, intravenous and inhaler steroids, inhaler β2 agonists and intravenous diphenhydramine were given in repeated doses. She was monitored and followed up in the emergency critical care unit. Daratumumab treatment with a split-dose schedule was planned after she fully recovered from all signs and symptoms. The total dose was divided into two doses and was given without any complications on two consecutive days. After that, she was also able to tolerate once a week 1840 mg of daratumumab in a single day.

DISCUSSION

There is a paucity of data regarding the best practice for instituting intravenous daratumumab in patients with morbid obesity regarding the infusion rate and duration, optimal dosing, and ideal way to cope with infusion-related reactions. Our case suggests a potential role for a split-dose schedule for patients with obesity and potential dose reductions and infusion-related reactions.

Substituting a randomised placebo control group with a historical placebo control in an endometriosis pain trial: a case study re-evaluating trial data using historical control data from another trial

OBJECTIVE

The substitution of an in-study control population with a historical control (HC) population is considered a viable option for reducing the necessary recruitment of control patients. However, it is necessary to evaluate whether this method is applicable to studies on indications targeting endometriosis-associated pelvic pain (EAPP). This study aims to evaluate the potential bias in the results of an EAPP study with an HC arm.

METHODS

For this case study, we re-evaluated data from a randomised, placebo-controlled trial using dienogest daily to treat EAPP with an HC arm based on data from a second randomised, placebo-controlled trial in the same indication. Propensity Score (PS) matching was used to match between the treatment and HC arm on all baseline variables. To evaluate the effect of matching on the introduced bias, we evaluated efficacy parameters with the full treatment and control group, as well as the matched group.

RESULTS

The difference between means (placebo minus treatment) in change in pain, as measured on the Visual Analogue Scale from baseline to end of treatment, deviates in the comparison treatment/pool of HC (7.15 (0.22 to 14.08)) from the overall in-study group (reference: 11.89 (6.06 to 17.73)). After PS matching on the baseline variables, the difference between means (11.79 (4.09 to 19.5)) is close to the reference.

CONCLUSIONS

Using HC with PS matching has proven to be useful in the setting of treating EAPP, while emphasis must be given to the selection mechanism and the underlying assumptions. This case study has shown that even for studies which are very similar in design, heterogeneity and between-study variations are present. With the use of an HC arm, it was possible to reproduce similar results than in the original study, while the PS matching improved the comparability considerably. For the main endpoint, PS matching could reproduce the original study results.

TRIAL REGISTRATION NUMBER

NCT00225199, NCT00185341.

Clinical Pharmacokinetics and Pharmacodynamics of Daratumumab

Daratumumab is a fully human, monoclonal immunoglobulin G1 and a first-in-class CD38-targeting drug approved by the US Food and Drug Administration for the treatment of patients with relapsed/refractory and newly diagnosed multiple myeloma or newly diagnosed light-chain amyloidosis. CD38 is heavily expressed on malignant myeloma cells, and daratumumab exerts anti-myeloma activity via immune-mediated mechanisms, direct induction of apoptosis, and immunomodulation. Daratumumab is used as monotherapy or in combination with standard-of-care myeloma therapies, including proteasome inhibitors, immunomodulatory agents, DNA-alkylating agents, and corticosteroids. Following an intravenous infusion, daratumumab exhibits nonlinear pharmacokinetics (PK), as clearance decreases with higher doses and over time because of target-mediated effects. Dosing schedules vary depending on indications and co-administered drugs, but generally daratumumab is administered weekly for 6-9 weeks followed by a less frequent dosing regimen, once every 2-4 weeks. Daratumumab exposure is strongly correlated with efficacy, and the exposure-efficacy relationship follows a maximal effect model, whereas exposure is not correlated with safety endpoints. The approved dose of 16 mg/kg of daratumumab results in the saturation of 99% of the target at the end of weekly dosing in most patients, and high target saturation is maintained over time during the less frequent dosing schedule. Infusion-related reactions are frequently observed in patients given daratumumab, particularly with the first infusion, thus prompting long durations of infusion (~ 7 h) and splitting of the first dose across 2 days. This led to the development of a subcutaneous delivery formulation for daratumumab (Dara-SC). Dara-SC provides a similar efficacy and safety profile to intravenous daratumumab (Dara-IV) but has a much lower rate of infusion-related reactions and a shorter infusion time. Exposure-response relationships for efficacy and safety endpoints were similar between Dara-SC and Dara-IV, and co-administered drugs with either Dara-IV or Dara-SC do not significantly affect daratumumab PK. Except for baseline myeloma type and albumin level, none of the other investigated disease and patient characteristics (renal/hepatic function, age, sex, race, weight, Eastern Cooperative Oncology Group performance status) was identified to have clinically relevant effects on exposure to daratumumab monotherapy or combination therapy regimens. Dara-IV exposure was significantly lower in patients with immunoglobulin G myeloma compared with patients with non-immunoglobulin G myeloma (p < 0.0001) and in patients with a lower albumin level, whereas the overall response rate was similar regardless of the myeloma type and albumin level. Daratumumab dose adjustment is not currently recommended based on disease and patient characteristics.

Clinical Administration Characteristics of Subcutaneous and Intravenous Administration of Daratumumab in Patients With Multiple Myeloma at Mayo Clinic Infusion Centers

PURPOSE

Median duration of daratumumab (DARA) administration for treatment of multiple myeloma is 3-7 hours for the intravenous formulation (DARA IV) and 3-5 minutes for the subcutaneous formulation (DARA SC). Here, we describe clinical administration characteristics of DARA using a novel method for data extraction from electronic health records.

METHODS

Time-based measurements were extracted using a scheduling/pharmacy software program that tracked patient movement through appointments for patients initiating DARA in Mayo Clinic infusion centers from April 5, 2017, to October 14, 2021. Cohorts included patients who received DARA IV or DARA SC, or converted from DARA IV to DARA SC. The DARA SC cohort was further analyzed before (DARA SC initial) and after (DARA SC shortened) a reduction in the postadministration observation time mandated by the treatment plan. Events associated with administration-related reactions (ARRs) were also identified.

RESULTS

Median total clinic times were 2.7-3.0 hours shorter for DARA SC versus DARA IV. Median clinic times were highest at dose 1 and decreased with subsequent doses. Median total chair times were 2.7-2.8 hours shorter for DARA SC versus DARA IV. Incidences of ARR-related events with DARA SC were low across doses.

CONCLUSION

Reduced clinic times were observed with DARA SC, indicating that use of DARA SC as a treatment option results in time savings that may free clinic resources. Furthermore, novel methods of electronic health record data extraction can provide insights that may help inform clinic resource optimization.

Daratumumab utilization and cost analysis among patients with multiple myeloma in a US community oncology setting

Background: The introduction of daratumumab into the treatment of multiple myeloma has improved outcomes in patients; however, community oncologists often dose more frequently than the US FDA-approved label. Materials and methods: Integra analyzed its database to elucidate daratumumab treatment patterns and the impact of increased utilization on the cost of care for multiple myeloma. Results: Following week 24, 671 (65%) of 1037 patients remained on daratumumab-containing regimens, with 330 patients continuing more frequent treatments than the expected once-every-4-weeks dosing described in the standard dosing schedule. Patients received an average of 14% more daratumumab doses than the FDA-approved label indicates, increasing the 1-year daratumumab costs by an estimated US$31,353. Conclusion: Daratumumab is utilized more frequently than the FDA-recommended dosing, leading to higher multiple myeloma treatment costs.

Impact of Split Dosing the First Rituximab Infusion in Patients with High Lymphocyte Count

The most common adverse reactions to rituximab are infusion-related reactions (IRR). We evaluated the efficacy of split dosing the first rituximab infusion over two days to reduce IRR incidence in patients with hematological cancer and a high lymphocyte count. This is a retrospective observational study conducted in two healthcare centers in Quebec, Canada. The study enrolled patients with white blood cell counts ≥25.0 × 10⁹/L who received their first rituximab dose for hematological cancer between December 2007 and May 2020. One healthcare center used asymmetrical split dosing, while the other used symmetrical split dosing. A total of 183 treatment episodes were collected from 143 patients. Among patients who received a fractionated dosing schedule, 42% developed an IRR from the first rituximab infusion compared with 50% for the standard protocol (adjusted relative risk, 0.89; p = 0.540). No significant difference was observed in IRR severity between either groups. However, 24% of patients who received the asymmetrical protocol developed an IRR compared to 68% for the symmetrical protocol (adjusted relative risk, 0.32; p = 0.003). These results suggest that an asymmetrical split dosing could be effective in reducing the incidence of IRR and is preferable to a symmetrical one.

Monoclonal antibodies in relapsed/refractory myeloma: updated evidence from clinical trials, real-life studies, and meta-analyses

Introduction: In the last few years, monoclonal antibodies have rapidly modified the therapeutic strategies for treating patients with multiple myeloma.Areas covered: In this review, the most recent literature data regarding indications for which monoclonal antibodies are currently or will be shortly approved as salvage therapies in relapsed/refractory myeloma are discussed. In particular, updated results until March 22, 2020 of antibodies directed against CD38 (daratumumab and isatuximab), SLAMF7 (elotuzumab), BCMA (GSK2857916/belantamab mafodotin), and PD-1/PD-1 L axis (nivolumab and pembrolizumab) will be analyzed in detail.Expert opinion: Monoclonal antibodies represent a new, very effective approach that will open novel and dynamic treatment scenarios for myeloma patients in the coming years. Optimal positioning and selection of different antibodies that are or will be soon available, appropriate combinations and careful evaluation of possible new toxicities should be considered in the future management of these patients.

Split First Dose Administration of Intravenous Daratumumab for the Treatment of Multiple Myeloma (MM): Clinical and Population Pharmacokinetic Analyses

Introduction

Daratumumab, a human immunoglobulin Gκ monoclonal antibody targeting CD38, is approved as monotherapy and in combination with standard-of-care regimens for multiple myeloma. In clinical studies, the median durations of the first, second, and subsequent intravenous infusions of daratumumab were 7.0, 4.3, and 3.4 h, respectively. Splitting the first intravenous infusion of daratumumab over 2 days is an approved alternative dosing regimen to reduce the duration of the first infusion and provide flexibility for patients and healthcare providers.

Methods

The feasibility of splitting the first 16-mg/kg infusion into two separate infusions of 8 mg/kg on Days 1 and 2 of the first treatment cycle was investigated in two cohorts [daratumumab, carfilzomib, and dexamethasone (D-Kd) and daratumumab, carfilzomib, lenalidomide, and dexamethasone (D-KRd)] of the phase 1b MMY1001 study. Additionally, a population pharmacokinetic (PK) analysis and simulations were used to compare the PK profiles of the split first dose regimen with the recommended single first dose regimens of daratumumab in previously approved indications.

Results

In MMY1001, following administration of the second half of a split first dose on Cycle 1 Day 2, postinfusion median (range) daratumumab concentrations were similar between split first dose [D-Kd, 254.9 (125.8–435.5) µg/ml; D-KRd, 277.2 (164.0–341.8) µg/ml; combined, 256.8 (125.8–435.5) µg/ml] and single first dose [D-Kd, 319.2 (237.5–394.7) µg/ml]. At the end of weekly dosing, median (range) Cycle 3 Day 1 preinfusion daratumumab concentrations were similar between split first dose [D-Kd, 663.9 (57.7–1110.7) µg/ml; D-KRd, 575.1 (237.9–825.5) µg/ml; combined, 639.2 (57.7–1110.7) µg/ml] and single first dose [D-Kd, 463.2 (355.9–792.9) µg/ml]. The population PK simulations demonstrated virtually identical PK profiles after the first day of treatment for all approved indications and recommended dosing schedules of daratumumab.

Conclusion

These data support the use of an alternative split first dose regimen of intravenous daratumumab for the treatment of MM.

Trial Registration

ClinicalTrials.gov number, NCT01998971.

Electronic Supplementary Material

The online version of this article (10.1007/s12325-020-01247-8) contains supplementary material, which is available to authorized users.