Assessing Measurable Residual Disease Tied to Better Outcome in Multiple Myeloma

By Megan Brooks

December 22, 2020

NEW YORK (Reuters Health) - Clinical decision-making based on assessment of measurable residual disease (MRD) is associated with better outcome in patients with multiple myeloma (MM), a real-world study indicates.

Patients who were MRD negative, as assessed by the U.S. Food and Drug Administration (FDA)-approved clonoSEQ assay from Adaptive Biotechnologies, had a longer progression-free survival (PFS).

"These results support the integration of MRD assessment" in the management of these patients, Dr. Joaquin Martinez-Lopez of the Complutense University of Madrid said during a presentation of the results at the American Society of Hematology (ASH) virtual annual meeting.

MRD refers to the small number of cancer cells that can remain after treatment and may eventually cause recurrence of the disease. Given a sufficient sample, the clonoSEQ assay for MRD can identify the presence of a single cancer cell in a sample of 1 million healthy cells, according to the manufacturer.

MRD in MM is increasingly being used in clinical trial to assess disease response to treatment and help predict duration of response, Dr. Martinez-Lopez explained. Yet there is only limited evidence to date for the use of MRD to guide clinical decisions.

To investigate, Dr. Martinez-Lopez and colleagues in Madrid and at the University of California, San Francisco (UCSF), did a retrospective review of 373 MM patients who had at least one MRD assessment using the clonoSEQ assay. They reviewed all available data on clinical and biological parameters and induction treatment and response were also reviewed.

Clinical decisions to change therapy based on MRD findings were made in three directions: 1) stop or reduce treatment after negative results; 2) increase intensity of treatment after positive results; 3) start a new treatment line after positive results.

A decision to change treatment was made in 58 patients (16%) based on their MRD status. Most of these decisions were made during the maintenance phase of treatment, although three patients avoided autologous stem cell transplant based on MRD testing.

Of the 58 patients with MRD-based therapy change, treatment was reduced or stopped in 24 patients, intensity of treatment was increased in 20 patients and a new treatment started in 13 patients.

The 58 patients in whom a clinical decision to change therapy was based on MRD status had a significantly improved PFS relative to patients who did not change treatment (median 97 vs. 75 months, P=0.006).

The study also confirmed that patients who achieve MRD negativity have a prolonged PFS relative to those who do not show negativity (median 97 vs. 57 months; P=0.0001).

"We are encouraged by this real-world data and the impact MRD testing can have on patients living with multiple myeloma, which is also evident in the patient care I provide," study investigator Dr. Jeffrey Wolf, director of the myeloma program at UCSF Helen Diller Family Comprehensive Cancer Center, said in a news release.

"These results support the integration of MRD assessment as a standard of care in the management of multiple myeloma patients. MRD assessment allows physicians and patients alike to have more confidence in their treatment decisions," Dr. Wolf added.

"The ability to accurately monitor disease burden in multiple myeloma is critical when making decisions that impact each patient's care. We are encouraged by the data emerging in MRD assessment, which we will believe will help myeloma patients and their doctors better manage their disease," Dr. Daniel Auclair, chief scientific officer of the Multiple Myeloma Research Foundation, said in the release.

The study had no commercial funding. Dr. Wolf has a financial relationship with the Adaptive Biotechnologies.

SOURCE: American Society of Hematology (ASH) Annual Meeting, presented December 6, 2020.