Current and potential roles of immuno-PET/-SPECT in CAR T-cell therapy

Chimeric antigen receptor (CAR) T-cell therapies have evolved as breakthrough treatment options for the management of hematological malignancies and are also being developed as therapeutics for solid tumors. However, despite the impressive patient responses from CD19-directed CAR T-cell therapies, ~ 40%−60% of these patients' cancers eventually relapse, with variable prognosis. Such relapses may occur due to a combination of molecular resistance mechanisms, including antigen loss or mutations, T-cell exhaustion, and progression of the immunosuppressive tumor microenvironment. This class of therapeutics is also associated with certain unique toxicities, such as cytokine release syndrome, immune effector cell-associated neurotoxicity syndrome, and other “on-target, off-tumor” toxicities, as well as anaphylactic effects. Furthermore, manufacturing limitations and challenges associated with solid tumor infiltration have delayed extensive applications. The molecular imaging modalities of immunological positron emission tomography and single-photon emission computed tomography (immuno-PET/-SPECT) offer a target-specific and highly sensitive, quantitative, non-invasive platform for longitudinal detection of dynamic variations in target antigen expression in the body. Leveraging these imaging strategies as guidance tools for use with CAR T-cell therapies may enable the timely identification of resistance mechanisms and/or toxic events when they occur, permitting effective therapeutic interventions. In addition, the utilization of these approaches in tracking the CAR T-cell pharmacokinetics during product development and optimization may help to assess their efficacy and accordingly to predict treatment outcomes. In this review, we focus on current challenges and potential opportunities in the application of immuno-PET/-SPECT imaging strategies to address the challenges encountered with CAR T-cell therapies

Impact of Detectable Monoclonal Protein at Diagnosis on Outcomes in Marginal Zone Lymphoma: A Multicenter Cohort Study

Given the paucity of data surrounding the prognostic relevance of monoclonal paraprotein (M-protein) in marginal zone lymphoma (MZL), we sought to evaluate the impact of detecting M-protein at diagnosis on outcomes in patients with MZL in a large retrospective cohort. The study included 547 patients receiving first-line therapy for MZL. M-protein was detectable at diagnosis in 173 (32%) patients. There was no significant difference in the time from diagnosis to initiation of any therapy (systemic and local) between the M-protein and no M-protein groups. Patients with M-protein at diagnosis had significantly inferior progression-free survival (PFS) compared with those without M-protein at diagnosis. After adjusting for factors associated with inferior PFS in univariate models, presence of M-protein remained significantly associated with inferior PFS (hazard ratio, 1.74; 95% confidence interval, 1.20-2.54; P = .004). We observed no significant difference in the PFS based on the type or quantity of M-protein at diagnosis. There were differential outcomes in PFS based on the first-line therapy in patients with M-protein at diagnosis, in that, those receiving immunochemotherapy had better outcomes compared with those receiving rituximab monotherapy. The cumulative incidence of relapse in stage 1 disease among the recipients of local therapy was higher in the presence of M-protein; however, this did not reach statistical significance. We found that M-protein at diagnosis was associated with a higher risk of histologic transformation. Because the PFS difference related to presence of M-protein was not observed in patients receiving bendamustine and rituximab, immunochemotherapy may be a preferred approach over rituximab monotherapy in this group and needs to be explored further

Impact of Early Relapse within 24 Months after First-Line Systemic Therapy (POD24) on Outcomes in Patients with Marginal Zone Lymphoma: A US Multisite Study

Progression of disease within 24 months (POD24) from diagnosis in marginal zone lymphoma (MZL) was shown to portend poor outcomes in prior studies. However, many patients with MZL do not require immediate therapy, and the time from diagnosis-to-treatment interval can be highly variable with no universal criteria to initiate systemic therapy. Hence, we sought to evaluate the prognostic relevance of early relapse or progression within 24 months from systemic therapy initiation in a large US cohort. The primary objective was to evaluate the overall survival (OS) in the two groups. The secondary objective included the evaluation of factors predictive of POD24 and the assessment of cumulative incidence of histologic transformation (HT) in POD24 versus non-POD24 groups. The study included 524 patients with 143 (27%) in POD24 and 381 (73%) in non-POD24 groups. Patients with POD24 had inferior OS compared to those without POD24, regardless of the type of systemic therapy received (rituximab monotherapy or immunochemotherapy) at diagnosis. After adjusting for factors associated with inferior OS in the univariate Cox model, POD24 remained associated with significantly inferior OS (HR = 2.50, 95% CI = 1.53-4.09, p = 0.0003) in multivariable analysis. The presence of monoclonal protein at diagnosis and those who received first-line rituximab monotherapy had higher odds of POD24 on logistic regression analysis. Patients with POD24 had a significantly higher risk for HT compared to those without POD24. POD24 in MZL might be associated with adverse biology and could be used as an additional information point in clinical trials and investigated as a marker for worse prognosis

Cost-Effectiveness Analysis of CAR T-Cell Therapies vs Antibody Drug Conjugates for Patients with Advanced Multiple Myeloma

Objectives Among advanced multiple myeloma (MM) patients, B-cell maturation antigen (BCMA) specific targets like Belantamab Mafodotin (belamaf) and CAR T-cell therapies have been shown to improve clinical outcomes, but at significant costs. To compare the expected costs per quality-adjusted life years (QALYs) gained among a hypothetical cohort of triple refractory MM patients treated with one of three BCMA-directed therapies: (1) idecabtagene vicleucel (ide-cel), (2) ciltacabtagene autoleucel (cilta-cel), and (3) belamaf for up to 20 months. Methods In this cost-effectiveness analysis, we built a Monte Carlo Markov Chain microsimulation model using estimates and parameters from the evidence on MM treatment for 10 000 hypothetical patients between the ages for 40 and 80. We assigned expected years of life remaining and made varying assumptions about survival beyond 5 years Results We predicted total cost of treatment for CAR-T therapy to be six times greater than for belamaf, but the QALYs gained from treatment are 6 to 8 times greater. Ide-cel was weakly dominated by cilta-cel and our base-case incremental cost effectiveness ratio (ICER) comparing cilta-cel with belamaf was $109,497 per QALY gained, averaging$123,618 in probabilistic sensitivity analyses. Conclusions These findings hinge on the assumption of longer-term survival but suggest that the use of CAR-T therapy is approaching standard ICER thresholds

Supplemental Material - Cost-Effectiveness Analysis of CAR T-Cell Therapies vs Antibody Drug Conjugates for Patients with Advanced Multiple Myeloma

Supplemental Material for Cost-Effectiveness Analysis of CAR T-Cell Therapies vs Antibody Drug Conjugates for Patients with Advanced Multiple Myeloma by Kandice A. Kapinos, Ellen Hu, Jigar Trivedi, Praveen Ramakrishnan Geethakumari, Ankit Kansagra in Cancer Control</p