Evaluation of Drug–Drug Interaction Potential of Talquetamab, a T-Cell-Redirecting GPRC5D × CD3 Bispecific Antibody, as a Result of Cytokine Release Syndrome in Patients with Relapsed/Refractory Multiple Myeloma in MonumenTAL-1, Using a Physiological

These modeling results suggest that IL-6 release due to talquetamab-induced cytokine release syndrome has limited impact on potential drug-drug interactions, with the highest likelihood of impact occurring from initiation of talquetamab step-up dosing up to 7 (QW) or 9 (Q2W) days after first treatment dose in cycle 1 and during and after cytokine release syndrome. Multiple myeloma can be treated with immunotherapies such as the bispecific antibody, talquetamab, which binds the novel antigen G protein-coupled receptor family C group 5 member D on multiple myeloma cells and CD3 on T cells and induces T-cell-mediated lysis of multiple myeloma cells. Following talquetamab treatment, many patients experience cytokine release syndrome, an inflammatory immune response where levels of proinflammatory cytokines, including interleukin (IL)-6, are increased. Interleukin-6 can suppress the activity of important enzymes in the body (cytochrome [CYP] P450s) that are involved in drug clearance. This study used a physiologically based pharmacokinetic computer model to investigate the potential impact of increased IL-6 levels on CYP450 enzymes to determine subsequent impact on drugs that are metabolized by CYP450 enzymes. The results showed no predicted interaction between median levels of IL-6 observed in patients and CYP substrates (such as caffeine and omeprazole) with talquetamab. In a simulation that assessed higher (maximum) IL-6 levels observed in patients, the predicted impact of IL-6 was minimal to weak for most of the CYP substrates assessed. The effect on CYP450 enzymatic activity was highest from initiation of talquetamab step-up dosing up to 7-9 days after the first treatment dose of talquetamab. These results suggest that, in this treatment time period, elevated IL-6 levels due to talquetamab-induced cytokine release syndrome have limited impact on drugs that are CYP substrates that may be used in conjunction with talquetamab, but that the concentration and toxicity of these drugs should be monitored and the dose of CYP substrate adjusted as required.