{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,24]],"date-time":"2026-10-24T01:20:17Z","timestamp":1792804817870,"version":"4.5.0"},"reference-count":37,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2025,5,28]],"date-time":"2025-05-28T00:00:00Z","timestamp":1748390400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Oncopeptides AB"},{"name":"KTH-Royal Institute of Technology","id":[{"id":"https:\/\/ror.org\/026vcq606","id-type":"ROR","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>B Cell Maturation Antigen (BCMA) has gained considerable attention as a target in directed therapies for multiple myeloma (MM) treatment, via immunoglobulin-based bispecific T cell engagers or CAR T cell strategies. We describe the development of alternative, non-immunoglobulin BCMA-recognising affinity proteins, based on the small (58 aa) three-helix bundle affibody scaffold. A first selection campaign using a na\u00efve affibody phage library resulted in the isolation of several BCMA-binding clones with different kinetic profiles. One clone showing the slowest dissociation kinetics was chosen as the template for the construction of two second-generation libraries. Characterization of output clones from selections using these libraries led to the identification of clone 1-E6, which demonstrated low nM affinity to BCMA and high thermal stability. Biosensor experiments showed that 1-E6 interfered with the binding of BCMA to both its natural ligand APRIL and to the clinically evaluated anti-BCMA monoclonal antibody belantamab, suggesting overlapping epitopes. A fluorescently labelled head-to-tail homodimer construct of 1-E6 showed specific binding to the BCMA+ MM.1s cell line in both flow cytometry and fluorescence microscopy. Taken together, the results suggest that the small anti-BCMA affibody 1-E6 could be an interesting alternative to antibody-based affinity units in the development of BCMA-targeted therapies and diagnostics.<\/jats:p>","DOI":"10.3390\/ijms26115186","type":"journal-article","created":{"date-parts":[[2025,5,28]],"date-time":"2025-05-28T08:12:47Z","timestamp":1748419967000},"page":"5186","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["An Anti-BCMA Affibody Affinity Protein for Therapeutic and Diagnostic Use in Multiple Myeloma"],"prefix":"10.3390","volume":"26","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7097-9408","authenticated-orcid":false,"given":"Kim Anh","family":"Giang","sequence":"first","affiliation":[{"name":"Department of Protein Science, KTH-Royal Institute of Technology, SE-114 28 Stockholm, Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Johan","family":"Nilvebrant","sequence":"additional","affiliation":[{"name":"Department of Protein Science, KTH-Royal Institute of Technology, SE-114 28 Stockholm, Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hao","family":"Liu","sequence":"additional","affiliation":[{"name":"Department of Protein Science, KTH-Royal Institute of Technology, SE-114 28 Stockholm, Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Harpa","family":"K\u00e1rad\u00f3ttir","sequence":"additional","affiliation":[{"name":"Oncopeptides AB, SE-171 48 Solna, Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yumei","family":"Diao","sequence":"additional","affiliation":[{"name":"Oncopeptides AB, SE-171 48 Solna, Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1777-2755","authenticated-orcid":false,"given":"Stefan","family":"Svensson Gelius","sequence":"additional","affiliation":[{"name":"Oncopeptides AB, SE-171 48 Solna, Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4214-6991","authenticated-orcid":false,"given":"Per-\u00c5ke","family":"Nygren","sequence":"additional","affiliation":[{"name":"Department of Protein Science, KTH-Royal Institute of Technology, SE-114 28 Stockholm, Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,5,28]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"309","DOI":"10.1016\/j.annonc.2020.11.014","article-title":"Multiple myeloma: EHA-ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up","volume":"32","author":"Dimopoulos","year":"2021","journal-title":"Ann. 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