CHICAGO – Subcutaneous (SC) daratumumab is noninferior to intravenous (IV) daratumumab for patients with relapsed or refractory multiple myeloma (MM), according findings from a phase 3 trial.
In the COLUMBA trial, SC daratumumab proved noninferior to IV daratumumab with regard to overall response rate and maximum trough concentration (Ctrough).
The safety profiles of the two formulations were similar, although patients who received SC daratumumab had a lower rate of infusion-related reactions. SC daratumumab also had a lower treatment burden.
“The COLUMBA study shows that [SC daratumumab] can be used in every myeloma patient [as a] single agent or, maybe in the future, in combination with the different backbones,” said Maria-Victoria Mateos, MD, PhD, of University Hospital of Salamanca (Spain).
Dr. Mateos presented results from theat the annual meeting of the American Society of Clinical Oncology.
Dr. Mateos cited a previous phase 1b study that had suggested that SC daratumumab might produce similar results as IV daratumumab () while providing a more convenient delivery method. She pointed out that infusions of IV daratumumab can last hours, while the SC formulation can be delivered in minutes.
The aim of the phase 3 COLUMBA study was to compare the IV and SC formulations head-to-head. The trial enrolled 522 patients with relapsed/refractory multiple myeloma. They were randomized to receive daratumumab SC (n = 263) or IV (n = 259).
The median patient age was 68 years (range, 33-92 years) in the IV arm and 65 years (range, 42-84 years) in the SC arm. Patients had received a median of four prior lines of therapy (range, 1-15 in the IV arm and 2-12 in the SC arm). Most patients were refractory to their last line of therapy – 85% in the IV arm and 80% in the SC arm – and most patients had standard-risk cytogenetics – 83% and 74%, respectively.
Patients received SC daratumumab at 1,800 mg and IV daratumumab at 16 mg/kg. Both were given weekly for cycles 1-2, every 2 weeks for cycles 3-6, and every 4 weeks thereafter until disease progression.
The median duration of the first infusion was 421 minutes in the IV arm and 5 minutes in the SC arm. The median duration of the second infusion was 255 minutes and 5 minutes, respectively, and the median duration of subsequent infusions was 205 minutes and 5 minutes, respectively.
At a median follow-up of 7.46 months, 57% of patients in each arm had discontinued the study treatment. The most common reasons for discontinuation were progression – 44% of the IV arm and 43% of the SC arm – and adverse events (AEs) – 8% and 7%, respectively.
Dr. Mateos said the safety profiles of IV and SC daratumumab were comparable. However, infusion-related reactions were significantly less likely in the SC arm, occurring in 12.7% of those patients and 34.5% of patients in the IV arm (P less than .0001).
Grade 3 or higher treatment-emergent AEs occurred in 49% of patients in the IV arm and 46% of those in the SC arm. Rates of grade 5 AEs were 7% and 5%, respectively. The most common grade 3/4 AEs (in the IV and SC arms, respectively) were anemia (14% and 13%), thrombocytopenia (14% for both), neutropenia (8% and 13%), lymphopenia (6% and 5%), and hypertension (6% and 3%).