Lau, Chris

Introduction: Teclistamab (Tec) is the first approved BCMA x CD3 bispecific antibody for the treatment of triple-class-exposed patients with relapsed/refractory multiple myeloma (RRMM) based on the pivotal MajesTEC-1 study. Tec was associated with high overall response rate (ORR) of 63% in heavily pretreated patients. After a longer follow-up of 30.4 months, CR rate was 46.1%, median duration of response (DOR) was 24 months (95% CI, 17.0 - not estimable), and median progression-free survival (PFS) was 11.4 months (95% CI, 8.8 - 16.4). Herein, we present updated analysis of real-world outcomes and safety with tec in RRMM with extended follow-up of more than 12 months. Methods: This is an international multicenter retrospective study of patients with RRMM treated with tec on-label at 9 academic centers from 5 countries (United States, United Kingdom, Greece, Spain, and Canada) through the International Myeloma Working Group (IMWG) Immunotherapy Committee. Patients with RRMM treated with commercial tec at the respective institutions between May 24, 2022 to January 4, 2024 were included. Median follow-up was 14 months with data collected until July 15, 2024. High-risk cytogenetic abnormalities (HRCA) was defined as 1q+, t(4;14), t(14;16), t(14;20), and/or del(17p). Response was assessed using the IMWG consensus criteria. Patient characteristics were summarized by frequency (percentage) or median (interquartile range [IQR] or range). PFS, overall survival (OS), DOR were evaluated using the Kaplan-Meier method. Results: There were 223 patients included in this analysis with the following characteristics: median age of 67 (range 33-91) with 24% ≥75 years; 45% female; 74% White, 10% Black, 9% Asian, and 7% other/unknown; 86 of 176 (49%) with high risk cytogenetics, including del(17p), t(4;14), t(14;16), t(14;20), and gain/amp 1q; 29.4% (37/126) with known extramedullary disease; 14% with creatinine clearance ≤30 ml/min. Patients received a median of 6 (IQR, 4-8) prior lines of therapy with 52% (107/206) being penta-drug refractory. Among 212 patients with available data, 161 (75.9%) patients would have been ineligible for MajesTEC-1. There were 94 (42%) patients who received prior BCMA-directed therapy (29.8% antibody-drug conjugate [ADC] alone; 45.7% CART alone; 6.3% bispecific antibody alone; 17.0% ADC and CART). Median time from diagnosis to tec initiation was 6.1 (range 0.6-29.2) years. For the 206 response-evaluable patients, ORR was 66%, including 25.2% ≥CR, 33.5% VGPR, and 7.3% PR. ORR for the 90 response-evaluable patients with prior BCMA-directed therapy was 54.5% (21.1% ≥CR, 26.7% VGPR, 6.7% PR). After a median follow-up of 14 (95%CI, 13-14) months, median PFS and OS were 8.8 (95% CI, 5.5-14) and 20 (95% CI, 18-not reached [NR]) months, respectively. 12-month PFS estimate was 46% (95% CI, 40%-54%), and 12-month OS rate was 65% (95% CI, 59%-72%). Median DOR was 17 (95% CI, 17-NR) months with 12-month estimate of 68% (95% CI, 60%-77%). Tec step-up dosing occurred in the outpatient setting for 57 (25.6%) patients. CRS occurred in 119 out of 222 (53.6%) patients with almost all being grade 1-2, except for 1 grade 4 event. ICANS occurred in 18 out of 216 (8.3%) patients (grade 1-2: 5.1%; grade 3-4: 2.8%). Any grade infection occurred in 130 (58.3%) patients; 25.1% of patients had grade ≥3 infection, including 10 patients with grade 5 infection. While receiving teclistamab, 79 (35.4%) patients had ≥2 infections. IVIG was given in 114 out of 164 (69.5%) patients. Conclusion: In this multicenter international real-world analysis of outcomes and safety associated with tec, ORR was high at 66% with 25.2% of patients achieving ≥CR. CR rates may be underestimated due to infrequent bone marrow confirmation in the real-world datasets. Encouragingly, ORR was 54.5% in BCMA exposed RRMM patients, including 21.1% with ≥CR. After a median follow-up of 14 months, heavily pretreated patients including patients with prior BCMA therapy had durable responses with median PFS of 8.8 months and median DOR of 17 months. There were no new safety signals noted in this real-world study. This is the largest real-world study to date of teclistamab with long-term follow-up of more than 12 months. Additional data including more patients, longer follow-up and results from difficult to treat subgroups will be presented at the meeting.

Introduction: Talquetamab (Talq) is a GPRC5D targeting bispecific antibody recently approved for the treatment of relapsed refractory multiple myeloma (MM) based on the MonumenTAL-1 study. Real World Evidence (RWE) is needed to understand the safety and efficacy of Talq in patients treated outside of a clinical trial as they may have different outcomes and toxicities. Here we report outcomes of 118 patients treated with Talq. Methods: Patients treated with standard-of-care Talq were included. Data was collected through a retrospective chart review from 01/2023 until 7/2024 from 7 International Myeloma Foundation (IMF) associated MM academic centers. Results: 118 patients were included in the analysis. The median age was 64, 37% had HR disease, 22% had EMD at presentation. The median LOT was 6, median number of immunotherapies before TAL was 2 (range 1,4) and 71% received prior BCMA therapy. 72% were triple refractory and 44% were penta refractory. 25% (n=60) would not have been eligible for TAL clinical trial due to exclusion criteria and15% had an ECOG of 2 or greater. 18% (n=97) received TAL as an outpatient and the median number of hospital days was 9 (0,37) for inpatients. CRS during Step up Dose (SUD) 1 was present in 30% Gr 1 (57%), Gr2 (11%), Gr 3 (6%), CRS during SUD 2 was present in 31%, Gr 1 (65%), Gr 2 (11%), CRS during SUD 3 when administered was present in 14% , Gr 1 (82%), Gr 2 (6%) and with first full dose was 12% , Gr 1 (71%), unknown (29%). ICANS occurred in 6% (7/97), Gr 1 (14%), Gr 2 (29%), Gr 3 (14%) and unknown in 43% there was no evidence of HLH. Skin toxicity was present in 62% of patients (n=105/118) with 4% needing dose interruptions and presented as rash (20%), dryness (42%) and itching (20%). Nail toxicity was present in 20% (n=65/118), with 9% needing dose interruptions. Dysgeusia was present in 51% (n=97/118), with 10% needing dose interruptions. Oral toxicity manifest as stomatitis (10%), glossitis (1%), ulcerations (2%), dry mouth (27%), was present in 34% (n=61/118), with 12.5% needing dose interruptions. Infections were present in 34% (n=82/118) and CMV reactivation in 23% while only 1 patient needed treatment for CMV. The Overall Response Rate (ORR) was 64.9% with a VGPR rate or higher of 43.3% in this population. Updated efficacy data including PFS will be reported at the time of presentation Conclusions: This is the first largest RWE of the safety and efficacy of Talq in a heavily pretreated population with a high prior BCMA exposure. The ORR is consistent with a prior study by Jakubowiak et al which showed an ORR OF 65.7% after prior T cell engagers. The safety profile - CRS, ICANS, skin and oral toxicities was similar to the MonumenTAL study, CMV reactivation was higher and this may be related to treatment with prior immunotherapies and should be monitored in the future. This report shows that Talq has a similar safety and efficacy profile in the real world when sequenced after prior BCMA therapies.