Follicular Lymphoma: Past, Present, and Future

Efficacy, safety, and cost-minimization analysis of axicabtagene ciloleucel and tisagenlecleucel CAR T-Cell therapies for treatment of relapsed or refractory follicular lymphoma

Axicabtagene ciloleucel (axi-cel) and tisagenlecleucel (tisa-cel) are chimeric antigen receptor (CAR) T-cell therapies used to treat adult patients with relapsed or refractory follicular lymphoma (rrFL) after two or more lines of systemic therapy. In the absence of head-to-head clinical trials, this study aimed to compare the efficacy, safety, and cost of axi-cel and tisa-cel in the treatment of rrFL after at least two lines of treatment. Overall response rate (ORR) and safety signals were compared using reporting odds ratios (RORs) with 95% confidence intervals (CIs) at p < 0.05. Progression-free survival (PFS), duration of response (DoR), and overall survival (OS) were compared using the Kaplan?Meier method with a log-rank test. Cost and cost-minimization analyses of drug acquisition, drug administration, serious adverse events (AEs), and relapsed management were calculated. Costs were extracted from the IBM-Micromedex Red Book, Centers for Medicare and Medicaid Services, and existing literature. Statistical analyses were conducted using Microsoft Excel and R version 4.0.5. No statistically significant differences were observed between axi-cel and tisa-cel in terms of ORR, DoR, and OS (p > 0.05). PFS was significantly better with tisa-cel (p < 0.05). Axi-cel was significantly associated with higher incidences of CRS, neurologic events, and grade 3-4 AEs than tisa-cel (ROR > 1, p < 0.05). Axi-cel and tisa-cel cost $512,021 and $450,885 per patient, respectively, resulting in savings of US$61,136 with tisa-cel over axi-cel. Tisa-cel appears to have a better safety profile, fewer serious AEs, lower mortality rate, and lower cost than axi-cel.

Machine learning models-based on integration of next-generation sequencing testing and tumor cell sizes improve subtype classification of mature B-cell neoplasms

Background

Next-generation sequencing (NGS) panels for mature B-cell neoplasms (MBNs) are widely applied clinically but have yet to be routinely used in a manner that is suitable for subtype differential diagnosis. This study retrospectively investigated newly diagnosed cases of MBNs from our laboratory to investigate mutation landscapes in Chinese patients with MBNs and to combine mutational information and machine learning (ML) into clinical applications for MBNs, especially for subtype classification.

Methods

Samples from the Catalogue Of Somatic Mutations In Cancer (COSMIC) database were collected for ML model construction and cases from our laboratory were used for ML model validation. Five repeats of 10-fold cross-validation Random Forest algorithm was used for ML model construction. Mutation detection was performed by NGS and tumor cell size was confirmed by cell morphology and/or flow cytometry in our laboratory.

Results

Totally 849 newly diagnosed MBN cases from our laboratory were retrospectively identified and included in mutational landscape analyses. Patterns of gene mutations in a variety of MBN subtypes were found, important to investigate tumorigenesis in MBNs. A long list of novel mutations was revealed, valuable to both functional studies and clinical applications. By combining gene mutation information revealed by NGS and ML, we established ML models that provide valuable information for MBN subtype classification. In total, 8895 cases of 8 subtypes of MBNs in the COSMIC database were collected and utilized for ML model construction, and the models were validated on the 849 MBN cases from our laboratory. A series of ML models was constructed in this study, and the most efficient model, with an accuracy of 0.87, was based on integration of NGS testing and tumor cell sizes.

Conclusions

The ML models were of great significance in the differential diagnosis of all cases and different MBN subtypes. Additionally, using NGS results to assist in subtype classification of MBNs by method of ML has positive clinical potential.

Biomarkers for Risk Stratification in Patients With Previously Untreated Follicular Lymphoma Receiving Anti-CD20-based Biological Therapy

Follicular lymphoma (FL) is an indolent B-cell neoplasm of germinal center origin. Standard treatment regimens consist of anti-CD20 therapy with or without chemotherapy. While high response rates to initial therapy are common, patients ultimately relapse or have progressive disease. Clinical risk factors such as the Follicular Lymphoma International Prognostic Index (FLIPI) have been identified, but there is a need for prognostic and predictive biomarkers. We studied markers of lymphoma cells and tumor microenvironment by immunohistochemistry in tissue samples from patients enrolled in 1 of 4 phase 2 trials of anti-CD20-based biological therapy for previously untreated grades 1 to 2 or 3A FL. Results were correlated with progression-free survival (PFS) and PFS status at 24 months. The 4 trials included 238 patients (51.1% male, median age: 55 y) with stage III, IV, or bulky stage II disease. By FLIPI, 24.6% had low-risk, 56.8% had intermediate-risk, and 18.6% had high-risk disease. The outcome differed significantly for patients treated with lenalidomide and rituximab (CALGB 50803) compared with the other 3 trials (median: PFS not reached vs. 3.0 y, hazard ratio=3.47, 95% confidence interval: 2.11-5.72); therefore, data were stratified by clinical trial (CALGB 50803 vs. all others) and adjusted for FLIPI risk group. Among 154 patients with available tissue, interfollicular BCL6 positivity, interfollicular CD10 positivity, and elevated Ki67 proliferation index ≥30% within neoplastic follicles were each associated with inferior PFS and a high risk of the early event by PFS status at 24 months. We identify promising biomarkers for FL risk stratification that warrant further validation in phase 3 trials.

The impact of prior malignancies on the development of second malignancies and survival in follicular lymphoma: A population-based study

We assessed the impact of a prior malignancy diagnosis (PMD) - as a potential proxy for genetic cancer susceptibility - on the development of a second primary malignancy (SPM) and mortality in follicular lymphoma (FL) patients. From the nationwide Netherlands Cancer Registry, we selected all adult FL patients diagnosed in 1994-2012 (n = 8028) and PMDs and SPMs relative to FL, with follow-up until 2017. We constructed two Fine and Gray models - with death as a competing risk - to assess the association between a PMD and SPM incidence. A PMD was associated with an increased incidence of SPMs (subdistribution hazard ratio [SHR], 1.30; 95% confidence interval [CI], 1.03-1.64) - especially carcinomas of the respiratory tract (SHR, 1.83; 95% CI, 1.10-3.05) and cutaneous squamous cell carcinomas (SHR, 1.58; 95% CI, 1.01-2.45) - and a higher risk of mortality in a multivariable model (HR, 1.43; 95% CI, 1.19-1.71). However, when additionally adjusted for the receipt of systemic therapy and/or radiotherapy before FL diagnosis, only patients who received such therapies had an increased incidence of SPMs (SHR, 1.40; 95% CI, 1.02-1.93). In conclusion, patients with a PMD had a higher rate of SPMs and mortality than those without a PMD, which might have resulted from therapy-related carcinogenesis.

Stage-specific trends in primary therapy and survival in follicular lymphoma: a nationwide population-based analysis in the Netherlands, 1989-2016

We assessed stage-specific trends in primary therapy and relative survival among adult follicular lymphoma (FL) patients diagnosed in the Netherlands between 1989-2016 (N = 12,372; median age, 62 years; and 21% stage I disease). Patients were stratified by disease stage and subsequently categorized into four calendar periods (1989-1995, 1996-2002, 2003-2008, and 2009-2016) and three age groups (18-60, 61-70, and >70 years). The use of radiotherapy in stage I FL remained relatively stable over time and across the three age groups (i.e., 66%, 54%, and 49% in 2009-2016, respectively). In stage II-IV FL, the start of chemotherapy within 12 months post-diagnosis decreased over time, indicating a broader application of a watch-and-wait approach. Relative survival improved considerably over time, especially since 2003 when rituximab was introduced in the Netherlands, and for stage III-IV FL patients and older age groups. Five-year relative survival for patients with stage I-II versus stage III-IV FL in the period 2009-2016 was 96% versus 90%, 93% versus 83%, and 92% versus 68% across the three age groups, respectively. Collectively, the improvement in survival since 2003 is accounted for by advances in FL management, particularly the implementation of rituximab. There remains, however, room for improvement among elderly stage III-IV FL patients.