This retrospective study was conducted at the University of Kansas Medical Center (Westwood, KS, USA) in collaboration with the United States Myeloma Innovations Research Collaborative (USMIRC). The study covered the period between January 2015 and June 2022 and received approval from the University of Kansas Institutional Review Board and conducted in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments. Subjects with a diagnosis of RRMM who received DPd in the second or subsequent lines of therapy were included. We reviewed electronic health records to extract relevant patient data including age, gender, race, MM type and stage, cytogenetics, and treatment lines including auto-HSCT. In addition, we obtained the hematological laboratory parameters of patients over the course of their DPd treatments, as well as any treatment-related adverse events described in their medical records.
The standard-of-care DPd regimen specified daratumumab administered weekly 16 mg/kg intravenously or 1,800 mg subcutaneously with hyaluronidase for the first 8 weeks, every 2 weeks from weeks 9 to 24, and then monthly until discontinuation of treatment due to disease progression or unacceptable toxicity. Pomalidomide dosage was 4 mg orally every day for 21 days as part of a 28-day cycle. Dexamethasone dosage was 20 mg weekly for patients aged 75 and older and 40 mg weekly for patients younger than 75. Antithrombotic and antiviral prophylaxis was carried out as recommended in clinical trials and practice guidelines. Patients were premedicated with glucocorticoids, acetaminophen, and diphenhydramine to prevent infusion reactions and, if required, with albuterol and montelukast in cases of underlying lung disease. Renal, hepatic, and hematological parameters were monitored during DPd therapy. Pomalidomide dosage was adjusted in line with the package insert if cytopenia occurred. Dose reduction was from 4 mg to 3 mg, then to 2 mg, and then to 1 mg; if the patient could not tolerate the lowest dose, pomalidomide was permanently discontinued. For daratumumab, there is no dose reduction, but delay in treatment until resolution of cytopenia and or infection.
Response to therapy was assessed using the International Myeloma Working Group (IMWG) criteria [12 (link)]. Grading of hematological and non-hematological adverse events was determined following the Common Terminology Criteria for Adverse Events (CTCAE) v5.0 [13 ]. Survival outcomes such as PFS and overall survival (OS) were estimated by means of Kaplan-Meier curves using log-rank testing.
The standard-of-care DPd regimen specified daratumumab administered weekly 16 mg/kg intravenously or 1,800 mg subcutaneously with hyaluronidase for the first 8 weeks, every 2 weeks from weeks 9 to 24, and then monthly until discontinuation of treatment due to disease progression or unacceptable toxicity. Pomalidomide dosage was 4 mg orally every day for 21 days as part of a 28-day cycle. Dexamethasone dosage was 20 mg weekly for patients aged 75 and older and 40 mg weekly for patients younger than 75. Antithrombotic and antiviral prophylaxis was carried out as recommended in clinical trials and practice guidelines. Patients were premedicated with glucocorticoids, acetaminophen, and diphenhydramine to prevent infusion reactions and, if required, with albuterol and montelukast in cases of underlying lung disease. Renal, hepatic, and hematological parameters were monitored during DPd therapy. Pomalidomide dosage was adjusted in line with the package insert if cytopenia occurred. Dose reduction was from 4 mg to 3 mg, then to 2 mg, and then to 1 mg; if the patient could not tolerate the lowest dose, pomalidomide was permanently discontinued. For daratumumab, there is no dose reduction, but delay in treatment until resolution of cytopenia and or infection.
Response to therapy was assessed using the International Myeloma Working Group (IMWG) criteria [12 (link)]. Grading of hematological and non-hematological adverse events was determined following the Common Terminology Criteria for Adverse Events (CTCAE) v5.0 [13 ]. Survival outcomes such as PFS and overall survival (OS) were estimated by means of Kaplan-Meier curves using log-rank testing.
