RESUMEN
PURPOSE: Chimeric antigen receptor T-cell (CAR T) therapy is capable of eliciting durable responses in patients with relapsed/refractory (R/R) lymphomas. However, most treated patients relapse. Patterns of failure after CAR T have not been previously characterized, and may provide insights into the mechanisms of resistance guiding future treatment strategies. METHODS AND MATERIALS: This is a retrospective analysis of patients with R/R large B-cell lymphoma who were treated with anti-CD19 CAR T at a National Cancer Institute-designated Comprehensive Cancer Center between 2015 and 2019. Pre- and posttreatment positron emission/computed tomography scans were analyzed to assess the progression of existing (local failures) versus new, nonoverlapping lesions (de novo failures) and identify lesions at a high risk for progression. RESULTS: A total of 469 pretreatment lesions in 63 patients were identified. At a median follow-up of 12.6 months, 36 patients (57%) recurred. Most (n = 31; 86%) had a component of local failure, and 13 patients (36%) exhibited strictly local failures. Even when progressing, 84% of recurrent patients continued to have a subset of pretreatment lesions maintain positron emission/computed tomography resolution. Lesions at a high risk for local failure included those with a diameter ≥5 cm (odds ratio [OR], 2.34; 95% confidence interval [CI], 1.55-3.55; P < .001), maximum standardized uptake value ≥10 (OR, 2.08; 95% CI, 1.38-3.12; P < .001), or those that were extranodal (OR, 1.49; 95% CI, 1.10-2.04; P = .01). In the 69 patients eligible for survival analysis, those with any lesion ≥5 cm (n = 46; 67%) experienced inferior progression-free survival (hazard ratio, 2.41; 95% CI, 1.15-5.04; P = .02) and overall survival (hazard ratio, 3.36; 95% CI, 1.17-9.96; P = .02). CONCLUSIONS: Most patients who recur after CAR T experience a component of local progression. Furthermore, lesions with high-risk features, particularly large size, were associated with inferior treatment efficacy and patient survival. Taken together, these observations suggest that lesion-specific resistance may contribute to CAR T treatment failure. Locally directed therapies to high-risk lesions, such as radiation therapy, may be a viable strategy to prevent CAR T failures in select patients.
Asunto(s)
Linfoma de Células B Grandes Difuso , Tratamiento Basado en Trasplante de Células y Tejidos , Humanos , Inmunoterapia Adoptiva , Linfoma de Células B Grandes Difuso/diagnóstico por imagen , Linfoma de Células B Grandes Difuso/terapia , Recurrencia Local de Neoplasia/terapia , Receptores Quiméricos de Antígenos , Estudios RetrospectivosRESUMEN
PURPOSE: In this first-in-human, phase I, GVHD prevention trial (NCT02891603), we combine pacritinib (PAC), a JAK2 inhibitor, with sirolimus to concurrently reduce T-cell costimulation via mTOR and IL6 activity. We evaluate the safety of pacritinib when administered with sirolimus plus low-dose tacrolimus (PAC/SIR/TAC) after allogeneic hematopoietic cell transplantation. PATIENTS AND METHODS: The preclinical efficacy and immune modulation of PAC/SIR were investigated in xenogeneic GVHD. Our phase I trial followed a 3+3 dose-escalation design, including dose level 1 (pacritinib 100 mg daily), level 2 (pacritinib 100 mg twice daily), and level 3 (pacritinib 200 mg twice daily). The primary endpoint was to identify the lowest biologically active and safe dose of pacritinib with SIR/TAC (n = 12). Acute GVHD was scored through day +100. Allografts included 8/8 HLA-matched related or unrelated donor peripheral blood stem cells. RESULTS: In mice, we show that dual JAK2/mTOR inhibition significantly reduces xenogeneic GVHD and increases peripheral regulatory T cell (Treg) potency as well as Treg induction from conventional CD4+ T cells. Pacritinib 100 mg twice a day was identified as the minimum biologically active and safe dose for further study. JAK2/mTOR inhibition suppresses pathogenic Th1 and Th17 cells, spares Tregs and antileukemia effector cells, and exhibits preliminary activity in preventing GVHD. PAC/SIR/TAC preserves donor cytomegalovirus (CMV) immunity and permits timely engraftment without cytopenias. CONCLUSIONS: We demonstrate that PAC/SIR/TAC is safe and preliminarily limits acute GVHD, preserves donor CMV immunity, and permits timely engraftment. The efficacy of PAC/SIR/TAC will be tested in our ongoing phase II GVHD prevention trial.