{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,13]],"date-time":"2026-10-13T07:35:17Z","timestamp":1791876917221,"version":"4.3.4"},"reference-count":43,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2025,6,6]],"date-time":"2025-06-06T00:00:00Z","timestamp":1749168000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Immunol."],"abstract":"<jats:p>Chimeric antigen receptor (CAR) -T cell therapy targeting B-cell maturation antigen (BCMA) has demonstrated significant efficacy and is considered an ideal target for the treatment of relapsed or refractory multiple myeloma (R\/R MM). However, due to the unstable or negative expression of BCMA, single-target BCMA CAR-T cell therapy still faces challenges, whereas targeting G protein-coupled receptor C5 family member D (GPRC5D) provides a new therapeutic direction. Clinical studies have shown that CAR-T cell therapy targeting GPRC5D has promising therapeutic potential for R\/R MM. Here, this study is a case report on a 61-year-old male R\/R MM patient with extramedullary disease (EMD) who participated in a clinical trial of anti-BCMA\/GPRC5D bispecific CAR-T cell therapy. Three months after infusion, the patient achieved a very good partial response (VGPR). Although the patient experienced four episodes of CAR-T cell expansion and developed grade 3 cytokine release syndrome (CRS), the symptoms were well controlled, and the treatment demonstrated generally safe. Our report analyzes the reasons for the four CAR-T cell expansions, highlighting the need for close monitoring and laboratory testing during anti-BCMA\/GPRC5D bispecific CAR-T cell therapy. Clinical trial registration: This study was registered on ClinicalTrials.gov, number NCT06068400.<\/jats:p>","DOI":"10.3389\/fimmu.2025.1607778","type":"journal-article","created":{"date-parts":[[2025,6,6]],"date-time":"2025-06-06T05:22:56Z","timestamp":1749187376000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":5,"title":["Case Report: Summary of multiple CAR-T expansions in anti-BCMA\/GPRC5D bispecific CAR-T cell therapy for multiple myeloma"],"prefix":"10.3389","volume":"16","author":[{"given":"Liya","family":"Wei","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xingxian","family":"Xiao","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xin","family":"Jing","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yuwei","family":"Zheng","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xiaoyan","family":"Sun","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wei","family":"Bai","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Manjun","family":"Li","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Min","family":"Luo","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yang","family":"Xiao","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2025,6,6]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"206","DOI":"10.1038\/s41408-024-01191-8","article-title":"CAR-T 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