Researchers have created a comprehensive single-cell map of the tumor immune microenvironment in multiple myeloma and its precursor conditions. The newly published findings provide insights that may explain why patients with similar diagnoses often have differences in disease progression, treatment response, and outcomes.
The study, published in Blood, was co-led by Robert Orlowski, MD, PhD, Professor of Lymphoma/Myeloma and Experimental Therapeutics at The University of Texas MD Anderson Cancer Center; and Linghua Wang, MD, PhD, Professor of Genomic Medicine, Executive Director and Head of the Center for Cellular Language Intelligence, Associate Member of the James P. Allison Institute, and focus area co-lead with the Institute for Data Science in Oncology at MD Anderson.
“Our delineation of five distinct tumor microenvironment ecotypes in the bone marrows of patients with plasma cell disorders provides a new framework to understand the critical role of the host immune system in the biology of these diseases,” Dr. Orlowski said. “Importantly, this information may provide added prognostic value beyond our current models, which predominantly focus solely on tumor cells. We are hopeful this may help guide treatment selection and provide new avenues to improve host immune system health as part of our strategy to ultimately cure myeloma.”
Study Methodology and Findings
The researchers used advanced single-cell sequencing technologies to analyze bone marrow samples from 235 patients with diagnoses spanning precursor conditions, newly diagnosed disease, and relapsed myeloma. The resulting atlas mapped immune cell populations and interactions across the disease spectrum, revealing five distinct subtypes, known as “ecotypes,” that have specific features.
The researchers discovered that the five ecotypes capture meaningful insights into distinct signaling pathways and genetic programs that were not fully explained by disease stage alone. One was marked by limited immune infiltration, while others showed features of immune surveillance, cytotoxic T-cell activity, inflammation, or immune cell stress.
These patterns may help explain why some tumors appear more visible to the immune system, while others grow in immune-suppressive environments that are less responsive to immune-based therapies. For example, some ecotypes were linked to tumor burden, survival and response to immunotherapies such as chimeric antigen receptor T-cell therapy and T-cell engagers.
Notably, certain ecotypes that were enriched in advanced disease could already be detected in precursor conditions—meaning there might be a way to stratify patients at risk for future disease progression.
These findings demonstrate that multiple myeloma is shaped not only by cancer cells, but also by the immune cells surrounding them. Factoring in these differences may help researchers better stratify patients and design treatment strategies. The study also points to immune pathways involving inflammation, metabolic stress, and immune suppression that could be studied as targets for future combination therapies.
Future studies will validate these ecotypes in larger patient populations to determine if they can be easily measured using available clinical tools. Additional work also is needed to examine whether specific ecotypes could help guide patient selection or treatment strategies.
“This work provides a comprehensive cellular roadmap of the immune landscape across multiple myeloma progression,” Dr. Wang said. “We hope this atlas will serve as a valuable resource for uncovering new mechanisms and therapeutic vulnerabilities in myeloma.”
DISCLOSURE: This study was funded in part by the Riney Family Multiple Myeloma Research Fund from the Paula and Rodger Riney Foundation, the Dr. Miriam and Sheldon G. Adelson Medical Research Foundation, the Myeloma Solutions Fund, the Multiple Myeloma Research Foundation, the National Cancer Institute, the Cancer Prevention and Research Institute of Texas, Break Through Cancer, the Leukemia & Lymphoma Society, the Brock Family Myeloma Research Fund, the Yates Ortiz Multiple Myeloma Fund, the Diane & John Grace Family Multiple Myeloma Research Fund, the Jake and Nina Kamin Endowment for Multiple Myeloma Research in Memory of Linda Chapman Golden, the Raymond Alexanian, M.D., Endowed Fellowship, the James B. & Marie R. and David & SaraAnne Baker Hopkins Research Endowment, and institutional funding. For full disclosures of the study authors, visit ashpublications.org/blood.
