PET2 response associated with survival in newly diagnosed diffuse large B-cell lymphoma: results of two independent prospective cohorts

Three-year follow-up analysis of first-line axicabtagene ciloleucel for high-risk large B-cell lymphoma: the ZUMA-12 study

ZUMA-12 is a multicenter phase 2 study evaluating axicabtagene ciloleucel (axi-cel) autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy as part of first-line treatment for high-risk large B-cell lymphoma (LBCL). In the primary efficacy analysis (n = 37; median follow-up, 15.9 months), axi-cel demonstrated a high rate of complete responses (CR; 78%) and a safety profile consistent with prior experience. Here, we assessed updated outcomes from ZUMA-12 in 40 treated patients after ≥3 years of follow-up. Eligible adults underwent leukapheresis, lymphodepleting chemotherapy, and  axi-cel infusion (2 × 106 CAR T cells/kg). Investigator-assessed CR, objective response, survival, safety, and CAR T-cell expansion were assessed. The CR rate among response-evaluable patients (n = 37) increased after the primary analysis to 86% (95% confidence interval [CI], 71%-95%), with a 92% objective response rate. After a median follow-up of 47.0 months (range, 37.1-57.8 months), 36-month estimates (95% CI) of duration of response and event-free, progression-free, and overall survival were 81.8% (63.9%-91.4%), 73.0% (55.6%-84.4%), 75.1% (57.5%-86.2%), and 81.1% (64.4%-90.5%), respectively. In total, 4 patients had new malignancies, 2 occurring after the data cutoff of the primary analysis; none were axi-cel-related. Eight patients died on study, 2 of whom died from nonrelapse mortality causes. After long-term follow-up, axi-cel demonstrated a high durable response rate, with no new safety signals after the primary analysis, suggestive of an effective first-line therapy with curative intent in high-risk LBCL. Further assessments are needed to determine its benefit vs standard of care. This trial was registered at clinicaltrials.gov, as NCT03761056.

Prognostic value of interim PET/CT in GCB and non-GCB DLBCL: comparison of the Deauville five-point scale and the ΔSUVmax method

BACKGROUND

This study aimed to identify the prognostic value of interim 18F-FDG PET/CT (I-PET) for germinal center B-cell-like (GCB) and non-GCB diffuse large B-cell lymphoma (DLBCL), respectively.

METHODS

Baseline 18F-FDG PET/CT (B-PET) and I-PET scans were performed in 112 patients with DLBCL. The prognostic value of I-PET using the Deauville five-point scale (D-5PS) criteria or percentage decrease in SUVmax (∆SUVmax) for GCB and non-GCB DLBCL were evaluated.

RESULTS

A significant difference in progression-free survival (PFS) was found between GCB and non-GCB DLBCL patients (P < 0.05). Based on D-5PS criteria, I-PET was divided into positive (score > 3) and negative (score ≤ 3) subgroups. Results indicated that I-PET using D-5PS criteria was an independent predictor for PFS of GCB DLBCL (P < 0.05), but not for overall survival (OS) (P > 0.05). For non-GCB DLBCL, PFS and OS were significantly higher in I-PET negative group than I-PET positive group (P < 0.05). Receiver operating characteristic (ROC) curve analysis proved that I-PET using ΔSUVmax can also effectively predict PFS and OS of non-GCB DLBCL (P < 0.05), but not for GCB DLBCL (P > 0.05). Based on the optimal threshold found by ROC curve analysis, patients were dichotomized into ∆SUVmax high and low groups. Log-rank test and Cox regression demonstrated that the layered ∆SUVmax was predictive of PFS and OS in non-GCB DLBCL (P < 0.05).

CONCLUSIONS

I-PET may have different prognostic values for GCB and non-GCB DLBCL. Thus, the pathology type of DLBCL may be considered while using I-PET as a prognostic tool in the future.

Interim FDG-PET/CT for Response Assessment of Lymphoma

The clinical use and prognostic value of interim FDG-PET/CT (iPET/CT), which is performed after treatment initiation but prior to its completion, varies by lymphoma subtype. Evidence supporting the prognostic value of iPET/CT is more robust for classical Hodgkin lymphoma (cHL), and in this lymphoma subtype, response-adapted treatment approaches guided by iPET/CT are a widely used standard of care for first-line therapy. The data supporting use of iPET/CT among patients with non-Hodgkin lymphoma (NHL) is less well-established, but failure to achieve complete metabolic response on iPET/CT is generally considered a poor prognostic factor with likely consequences for progression free survival. This review will present the available evidence supporting use of iPET/CT in lymphoma patients, particularly as it relates to prognostication and the ability to inform response-adapted treatment strategies. The latter will be addressed through a discussion on the major iPET-response adapted clinical trials with mention of ongoing trials. Special attention will be given to cHL and a few subtypes of NHL, including diffuse large B cell lymphoma (DLBCL), follicular lymphoma (FL), and peripheral T cell lymphoma (PTCL).