van der Schans Jort J, Wang Ziyu, van Arkel Jennemiek, van Schaik Thijs, Katsarou Afroditi, Ruiter Ruud, Baardemans Thomas, Yuan Huipin, de Bruijn Joost, Zweegman Sonja, van de Donk Niels W C J, Groen Richard W J, Themeli Maria, Mutis Tuna
Department of Hematology, Amsterdam UMC, Location VU University Medical Center, Cancer Center Amsterdam, Amsterdam, the Netherlands.
Kuros Biosciences BV, Bilthoven, the Netherlands.
Clin Cancer Res. 2023 Oct 13;29(20):4219-4229. doi: 10.1158/1078-0432.CCR-23-0132.
The success of B-cell maturation antigen (BCMA)-specific chimeric antigen receptor (CAR) T cells illustrates the potential of this novel therapy for multiple myeloma. Nonetheless, broadening CAR T-cell therapy beyond BCMA requires inventive strategies as there are only a few multiple myeloma- or plasma cell-specific target antigens. We investigated the feasibility of achieving multiple myeloma specificity by dual-split CD38/CD138 CAR targeting, whereby the stimulatory and costimulatory signals for T-cell activation are split into two separate stimulatory (sCAR) and costimulatory CARs (cCAR).
Using various combinations of CD38 and CD138 sCARs and cCARs with different affinities, we generated several dual-split CAR T cells and analyzed them for multiple myeloma-specific effector functions in vitro. The best-functioning CAR T cells were tested in vivo in a murine xenograft model.
We found optimal designs of both CD38sCAR/CD138cCAR and CD138sCAR/CD38cCAR combinations, that effectively lysed multiple myeloma cells but spared single CD38- or CD138-positive healthy hematopoietic cells. While the CD38sCAR/CD138cCAR T cells achieved multiple myeloma-specific activity solely due to the low affinity of the CD38sCARs, the multiple myeloma-specific cytotoxicity, cytokine release, and proliferation of CD138sCAR/CD38cCAR T cells were established through a true combinatorial stimulatory and costimulatory effect. The most optimal combination comprised a low-affinity CD138sCAR combined with a high-affinity CD38cCAR. These CD138sCAR/CD38cCAR T cells also showed dual-antigen specific anti-multiple myeloma effects in vivo. Importantly, they were also effective against multiple myeloma cells from daratumumab pretreated patients with decreased CD38 expression levels.
We demonstrate the possibility to specifically target multiple myeloma cells, even after CD38 targeted therapy, with carefully-designed dual-split CARs directed against CD38 and CD138.
B细胞成熟抗原（BCMA）特异性嵌合抗原受体（CAR）T细胞的成功证明了这种新型疗法对多发性骨髓瘤的潜力。尽管如此，将CAR T细胞疗法扩展到BCMA之外需要创新策略，因为多发性骨髓瘤或浆细胞特异性靶抗原很少。我们研究了通过双分裂CD38/CD138 CAR靶向实现多发性骨髓瘤特异性的可行性，即T细胞激活的刺激信号和共刺激信号被分为两个单独的刺激型CAR（sCAR）和共刺激型CAR（cCAR）。
使用具有不同亲和力的CD38和CD138 sCAR和cCAR的各种组合，我们生成了几种双分裂CAR T细胞，并在体外分析它们的多发性骨髓瘤特异性效应功能。在小鼠异种移植模型中对功能最佳的CAR T细胞进行体内测试。
我们发现了CD38sCAR/CD138cCAR和CD138sCAR/CD38cCAR组合的最佳设计，它们能有效裂解多发性骨髓瘤细胞，但不损伤单个CD38或CD138阳性的健康造血细胞。虽然CD38sCAR/CD138cCAR T细胞仅由于CD38sCAR的低亲和力而具有多发性骨髓瘤特异性活性，但CD138sCAR/CD38cCAR T细胞的多发性骨髓瘤特异性细胞毒性作用、细胞因子释放和增殖是通过真正的组合刺激和共刺激作用建立的。最优化的组合包括低亲和力的CD138sCAR与高亲和力的CD38cCAR。这些CD138sCAR/CD38cCAR T细胞在体内也显示出双抗原特异性抗多发性骨髓瘤作用。重要的是，它们对来自经达雷妥尤单抗预处理且CD38表达水平降低的患者的多发性骨髓瘤细胞也有效。
我们证明了通过精心设计的针对CD38和CD138的双分裂CAR，即使在CD38靶向治疗后，也有可能特异性靶向多发性骨髓瘤细胞。
