Improved outcomes for relapsed/refractory multiple myeloma patients treated with daratumumab.

This study evaluated the effect of daratumumab (Darzalex)-based treatments on sustained minimal residual disease (MRD) negativity and outcomes in patients with relapsed/refractory (RR) multiple myeloma (MM).

The data showed that treatments including daratumumab led to sustained MRD negativity and improved outcomes in these patients.

MM is associated with abnormal plasma cells. These abnormal plasma cells assemble in the bone marrow and affect the function of other cells. Standard treatments for MM have prolonged patient survival but relapses often occur. Patients with RR disease experience disease progression or a lack of response to initial treatments.

After the patient receives treatment, a few abnormal residual cells can remain in the body. These are called MRD. If these cells are undetectable by tests, then a negative status for MRD is given. A negative MRD status is associated with improved patient outcomes like progression-free survival.

Daratumumab is an immunotherapy that kills MM cells or allows the immune system to kill them. Previous studies have shown that daratumumab-based therapies improve the survival of patients with RRMM. However, if it is also associated with sustained MRD-negative status is still under investigation.

The study analyzed the results of two trials evaluating daratumumab-based therapies in patients with RRMM. Patients were treated with either Rd (lenalidomide and dexamethasone) compared to D (daratumumab)-Rd or Vd (bortezomib and dexamethasone) compared to D-Vd. MDR negativity status and patient outcomes were evaluated. Patients were followed up for an average of 50.2 to 54.8 months.

The MRD-negativity rate was significantly higher in patients that received daratumumab. D-Rd was associated with a 32.5% MRD-negativity rate compared to 6.7% for Rd. Similarly, D-Vd had a 15.1% MRD-negativity rate compared to 1.6% for Vd.

More patients treated with daratumumab achieved MRD-negativity that lasted for 6 months or more in both studies. 20.3% of patients treated with D-Rd had MRD-negativity status for 6 months or more compared to 2.1% in the Rd group. 10.4% of those treated with D-Vd had sustained MRD-negative status for 6 months or more compared to 1.2% in the Vd group. 

16.1% of patients treated with D-Rd had MRD-negativity sustained at 12 months or more compared to 1.4% in the Rd group. 6.4% in the D-Vd group and 0% in the Vd group had MRD-negativity sustained at 12 months or more.

This study showed that daratumumab-based treatments were associated with sustained MRD-negativity in patients with RRMM.