Dr Mouhieddine on a Study of Correlates of Response to Bispecific Antibodies in Myeloma

“We looked at different measures from regular blood tests that are a part of the SOC, and we found 2 promising and predictive markers: ferritin and ALC.”

Tarek Mouhieddine, MD, a medical oncologist at Dana-Farber Cancer Institute and an instructor in medicine at Harvard Medical School, discussed the background of a retrospective study of baseline and longitudinal immune and inflammatory correlates of response to bispecific antibodies for the treatment of patients with relapsed/refractory multiple myeloma.

Although bispecific antibodies are steadily making their way into the multiple myeloma treatment paradigm, prognostic and predictive biomarkers of response to these agents that are clinically available, feasible, and cost-effective have yet to be developed, Mouhieddine began. In response to this unmet need, Mouhieddine and coauthors conducted a retrospective study, findings from which were presented during the 22nd Annual International Myeloma Society Meeting and Exposition. The study included 325 patients with relapsed/refractory multiple myeloma who received bispecific antibody therapy at The Mount Sinai Hospital, including in standard-of-care (SOC) practice or as part of a clinical trial, he explained. The study authors assessed patients’ responses to treatment and compared them with various measures from SOC blood testing, he continued.

The study authors identified the inflammatory marker ferritin and absolute lymphocyte count (ALC) as 2 potential markers of response to bispecific antibody treatment, Mouhieddine concluded. High levels of ferritin have previously been linked to worse outcomes in patients with multiple myeloma, including in those treated with CAR T-cell therapy. Low effector T-cell counts, which can be reflected in ALC figures, have been shown to potentially impair bispecific antibody–mediated cytotoxicity.

Patients included in the study received BCMA- (49%), GPRC5D- (44%), or FcRH5- (7%) targeted agents. Most patients (76%) were treated at the recommended phase 2 doses of these agents, and 11% of patients received combination therapy. The median age was 68 years (interquartile range, 60-75), and 46% of patients had high-risk cytogenetics.