Real-world patient characteristics, treatment patterns, and outcomes among relapsed/refractory multiple myeloma patients receiving talquetamab-tgvs

Abstract Introduction Multiple myeloma (MM), the second most common hematologic cancer, is estimated to have 36,110 new United States (US) cases in 2025; patients (pts) with relapse/refractory MM (RRMM) face poor outcomes despite treatment advances. On 09 August 2023, the Food and Drug Administration gave accelerated approval to talquetamab-tgvs (TAL) for adults with RRMM after ≥4 prior lines of therapies (LOT), including a proteasome inhibitor, an immunomodulatory agent, and an anti-CD38 monoclonal antibody (i.e., triple class exposed TCE). TAL uses two or three step-up doses prior to full treatment doses (mg/kg: 0.4 weekly QW or 0.8 biweekly Q2W) to mitigate cytokine release syndrome. The MonumenTAL-1 trial showed overall response rate (ORR) of ~73% for both doses, median duration of response (DOR): 9.5 months (0.4 mg/kg); 16.9 months (0.8 mg/kg) and 85% maintained response ≥9 months. This study examines real-world treatment patterns and outcomes in RRMM pts managed in community settings, in which evidence is limited. Methods This retrospective, observational, multi-site medical chart review study used data from the Cardinal Health Oncology Provider Extended Network (OPEN). Data of adults ≥18 years with confirmed RRMM who initiated TAL on or after 09 August 2023, outside of a clinical trial and at least one month before data collection, were abstracted by participating physicians. Descriptive statistics summarize demographics and treatment patterns; and Kaplan-Meier method for real-world DOR (rwDOR), progression-free survival (PFS) and overall survival (OS). Results were reported for the overall cohort and for pts who initiated TAL pursuant to US Prescribing Information (USPI) – TCE, initiated TAL as monotherapy after at least four prior LOTs, non-bridging. Results A total of 176 pts were abstracted by 25 physicians, the majority of whom (72.0%) practiced in community settings; 60.8% (n=107) of pts met the USPI cohort criteria. Overall, pts had median age of 66.3 years (interquartile range: 61.0-70.7) at initial RRMM diagnosis with 60.2% ≥65 years, 59.7% male, and 70.5% White. Median follow-up was 3.9 months (IQR: 2.3-8.1). At TAL initiation median BMI was 25.6, 26.7% had an ECOG score ≥2, 51.2% (86/168) of pts with available cytogenetics were high-risk, 64.2% had lytic bone lesions, 46.5% (74/159) of pts with available International Staging System (ISS) or Revised ISS diagnosis were grade 3, and 5.1% had extramedullary disease. In the LOT prior to TAL initiation, 31.3% received CART, 17.0% bispecific antibodies, and 0.0% BCMA-targeted antibody drug conjugates. Most pts received three (36.9%) or four (44.3%) LOTs prior to TAL initiation. A total of 170 pts (96.6%) received the full treatment dose, with 50.6% and 49.4% on the 0.4 mg/kg QW and 0.8 mg/kg Q2W initial dosing schedule, respectively. Overall, the rwORR was 81.0% among 119 response-evaluable pts and median rwDOR was 10.8 months; 38.8% of pts had very good partial response or better. At 6 months, the overall survival rate was 85.9%, and 82.5% of patients were progression-free. In the USPI cohort, rwORR was 85.3% among 81 response-evaluable pts and median rwDOR was 10.8 months. Cytokine release syndrome (CRS) was reported in 61 (34.7%) pts, all of which were grade ≤2; most (88.5%) were grade 1. Data on other G-protein coupled receptor 5D (GPRC5D)-related AEs will be included in future updates. Among patients who completed SUD and received the full treatment dose, 29.1% initiated TAL in the community setting. Forty-four (25.0%) pts discontinued TAL. Among all pts, discontinuation rates due to AE/toxicity and patient choice were both 4.0%. Five (2.8%) pts initiated a LOT after TAL discontinuation. Conclusion This real-world study of pts initiating TAL primarily in community settings demonstrated a strong treatment response consistent with pivotal trial findings. Most CRS events were mild and approximately one third of the patients were able to initiate TAL in the community setting. While cautious interpretability is applicable given short follow up period and high censoring, overall, these results support TAL as an effective treatment for pts with RRMM in community settings.