Patient and disease characteristics
| Total cohort n=129 | German cohort n=63 | US cohort n=66 | P | |
| Age, years | ||||
| Median (range) | 64 (34–83) | 60 (34–77) | 66 (35–83) | 0.007 |
| ≥70, No. (%) | 36 (28) | 14 (22) | 22 (33) | 0.17 |
| Sex, No. (%) | ||||
| Male | 87 (67) | 45 (71) | 42 (64) | 0.36 |
| Female | 42 (33) | 18 (29) | 24 (36) | |
| ECOG*, No. (%) | ||||
| 0–1 | 111 (96) | 63 (100) | 48 (91) | 0.02 |
| 2–3 | 5 (4) | 0 (0) | 5 (9) | |
| Unknown | 13 | 0 | 13 | |
| ISS stage*, No. (%) | ||||
| I | 63 (58) | 37 (71) | 26 (46) | 0.03 |
| II | 35 (32) | 11 (21) | 24 (43) | |
| III | 10 (9) | 4 (8) | 6 (11) | |
| Unknown | 21 | 11 | 10 | |
| R-ISS stage*, No. (%) | ||||
| I | 24 (23) | 18 (35) | 6 (11) | 0.009 |
| II | 75 (71) | 31 (61) | 44 (81) | |
| III | 6 (6) | 2 (4) | 47 | |
| Unknown | 24 | 12 | 12 | |
| Extramedullary disease*, No. (%) | ||||
| Yes | 48 (38) | 30 (50) | 18 (27) | 0.01 |
| Bone-associated | 16 (13) | 13 (22) | 3 (5) | |
| Extraosseous | 32 (25) | 17 (28) | 15 (23) | |
| No | 78 (62) | 30 (50) | 48 (73) | |
| Unknown | 3 | 3 | 0 | |
| Cytogenetics, No. (%) | ||||
| Standard risk | 74 (60) | 27 (45) | 47 (75) | 0.0009 |
| High risk | 49 (40) | 33 (55) | 16 (25) | |
| del(17p) | 30 (24) | 20 (33) | 10 (16) | |
| t(4;14) | 19 (15) | 12 (20) | 7 (11) | |
| t(14;16) | 5 (4) | 3 (5) | 2 (3) | |
| High risk with 1q | 74 (60) | 44 (73) | 30 (48) | 0.006 |
| 1q+ | 54 (44) | 30 (50) | 24 (38) | |
| Unknown | 6 | 3 | 3 | |
| Bone marrow burden†, No. (%) | ||||
| <50% | 57 (80) | 20 (80) | 37 (80) | >0.99 |
| ≥50% | 14 (20) | 5 (20) | 9 (20) | |
| Unknown | 58 | 38 | 20 | |
| Prior lines of therapy, median (95% CI) | 5 (5-6) | 5 (5-6) | 6 (5-6) | 0.67 |
| Prior therapies, No. (%) | ||||
| Double-class refractory‡ | 114 (88) | 48 (76) | 66 (100) | <0.0001 |
| Triple-class refractory§ | 107 (83) | 42 (67) | 65 (98) | <0.0001 |
| Penta-drug exposed¶ | 100 (78) | 50 (79) | 50 (76) | 0.68 |
| Penta-drug refractory¶ | 41 (32) | 11 (17) | 30 (45) | 0.0007 |
| Autologous SCT | 116 (90) | 61 (97) | 55 (83) | 0.02 |
| Allogeneic SCT | 12 (9) | 12 (19) | 0 (0) | 0.0001 |
| BCMA-targeted therapy | 22 (17) | 4 (6) | 18 (27) | 0.002 |
| Belantamab mafodotin | 21 (16) | 3 (5) | 18 (27) | 0.0006 |
| Bispecific antibody | 4 (3) | 3 (5) | 1 (2) | 0.36 |
| Teclistamab | 2 (2) | 1 (2) | 1 (2) | >0.99 |
| Talquetamab | 2 (2) | 2 (3) | 0 (0) | 0.24 |
| Systemic bridging therapy**, No. (%) | ||||
| Yes | 111 (86) | 59 (94) | 52 (79) | 0.02 |
| Immunomodulatory agent | 50 (39) | 36 (57) | 14 (21) | <0.0001 |
| Proteasome inhibitor | 71 (55) | 40 (63) | 31 (47) | 0.08 |
| Anti-CD38 antibody | 36 (28) | 25 (40) | 11 (17) | 0.006 |
| Classical cytotoxic agent | 61 (47) | 39 (62) | 22 (33) | 0.002 |
| No | 18 (14) | 4 (6) | 14 (21) | |
| Radiotherapy | 2 (2) | 0 (0) | 2 (3) | 0.50 |
| Watch-and-wait | 16 (12) | 4 (6) | 12 (18) | 0.06 |
| Lymphodepletion, No. (%) | ||||
| Fludarabine/cyclophosphamide | 125 (97) | 63 (100) | 62 (94) | 0.12 |
| Bendamustine | 4 (3) | 0 (0) | 4 (6) | |
| Vein-to-vein time, days, median (range) | 49 (35–138) | 56 (42–138) | 45 (35–113) | <0.0001 |
| Time from initial diagnosis to CAR T-cell therapy, years, median (range) | 6.2 (0.6–17.6) | 6.4 (1.4–17.6) | 5.5 (0.6–14.4) | 0.19 |
*Determined prior to lymphodepletion (baseline).
†Last bone marrow status determined within 90 days prior to CAR T-cell therapy.
‡Refractory to an immunomodulatory agent and a proteasome inhibitor.
§Refractory to an immunomodulatory agent, a proteasome inhibitor and an anti-CD38 monoclonal antibody.
¶ Exposed/refractory to lenalidomide, pomalidomide, bortezomib, carfilzomib and daratumumab.
**Systemic treatment administered between leukapheresis and lymphodepletion (at least one drug).
BCMA, B-cell maturation antigen; CAR, chimeric antigen receptor; ECOG, Eastern Cooperative Oncology Group performance status; ISS, International Staging System; R-ISS, Revised International Staging System; SCT, stem cell transplant.