Talquetamab Versus Real-World Physician's Choice Treatment: Comparative Effectiveness in Patients With Triple-Class Exposed Relapsed/Refractory Multiple Myeloma.

Background: Talquetamab is approved for treatment of triple-class exposed (TCE) patients with relapsed/refractory multiple myeloma (RRMM). We evaluated the comparative effectiveness of talquetamab in the MonumenTAL-1 study versus real-world physician's choice (RW) treatment.

Methods: An external control arm for MonumenTAL-1 was created from patients in the Flatiron Health database who satisfied MonumenTAL-1 eligibility criteria (n = 629 with 1169 eligible lines of therapy). Patient-level data from MonumenTAL-1 were included for patients who received subcutaneous talquetamab 0.4 mg/kg QW (n = 143) and 0.8 mg/kg Q2W (n = 145). After adjusting for baseline covariate imbalances, comparative effectiveness was assessed for progression-free survival (PFS), time to next treatment (TTNT), and overall survival (OS).

Results: Baseline covariates were comparable across cohorts after adjustment. Talquetamab 0.4 mg/kg QW and 0.8 mg/kg Q2W cohorts, respectively, showed significant improvement in PFS (HR, 0.55 [95% CI, 0.44-0.69; P < .0001; median, 7.5 vs. 4.0 months] and 0.40 [95% CI, 0.31-0.53; P < .0001; median, 14.2 vs. 4.0 months]), TTNT (HR, 0.59 [95% CI, 0.47-0.74; P < .0001; median, 9.1 vs. 5.1 months] and 0.45 [95% CI, 0.35-0.59; P < .0001; median, 13.3 vs. 5.1 months]), and OS (HR, 0.56 [95% CI, 0.40-0.78; P = .0007; median, NR vs. 16.5 months] and 0.48 [95% CI, 0.33-0.70; P = 0.0002; median NR vs. 15.9 months]) versus RW treatment.

Conclusions: Both talquetamab schedules demonstrated superior effectiveness over RW treatment for all outcomes assessed. These data suggest talquetamab as an effective immunotherapy option in patients with TCE RRMM.