Follicular lymphoma: 2015 update on diagnosis and management

Cost-Effectiveness of Axicabtagene Ciloleucel for Adult Patients With Relapsed or Refractory Follicular Lymphoma in the United States

OBJECTIVES

The results of a recent single-arm trial (ZUMA-5) of axicabtagene ciloleucel (axi-cel) for relapsed/refractory (r/r) follicular lymphoma (FL) demonstrated high rates of durable response and tolerable toxicity among treated patients. To quantify the value of axi-cel compared with standard of care (SOC) to manage r/r FL patients who have had at least 2 prior lines of systemic therapy (3L+), a cost-effectiveness model was developed from a US third-party payer perspective.

METHODS

A 3-state partitioned-survival cost-effectiveness model was developed with a lifetime horizon. Patient-level analyses of the 36-month ZUMA-5 (axi-cel) and SCHOLAR-5 (SOC) studies were used to extrapolate progression-free and overall survivals. After 5 years of survival, an estimated 40% of the modeled population was assumed to experience long-term remission based on literature. Results include the incremental cost-effectiveness ratio (ICER) measured as incremental cost per quality-adjusted life year (QALY) gained. One-way sensitivity analysis, probabilistic sensitivity analysis, and scenario analyses were performed. All outcomes were discounted 3% per year.

RESULTS

Axi-cel led to an increase of 4.28 life-years, 3.64 QALYs, and a total cost increase of $321 192 relative to SOC, resulting in an ICER of $88 300 per QALY. Across all parameters varied in the one-way sensitivity analysis, the ICER varied between $133 030 and $67 277. In the probabilistic sensitivity analysis, axi-cel had a 99% probability of being cost-effective across 5000 iterations using a $150 000 willingness-to-pay threshold.

CONCLUSIONS

Given the robustness of the model results and sensitivity analyses, axi-cel is expected to be a cost-effective treatment in 3L+ r/r FL.

Comparative effectiveness between mosunetuzumab monotherapy clinical trial and real-world data in relapsed/refractory follicular lymphoma in third or subsequent lines of systemic therapy

A comparison of clinical outcomes in the third or subsequent line (3 L+) of systemic therapy between a real-world data (RWD) external control cohort and a mosunetuzumab single-arm clinical trial cohort is presented. Data for 3 L + patients with relapsed/refractory follicular lymphoma (FL) were obtained from the mosunetuzumab single-arm trial (n = 90) and a US electronic health records database (n = 158), with patients meeting key eligibility criteria from the trial, balanced on pre-specified prognostic factors. Overall response and complete response rates were 80% and 60% in the mosunetuzumab cohort and 75% and 33% in the RWD cohort, odds ratios of 1.23 (95% CI, 0.52-2.93) and 3.18 (95% CI, 1.41-7.17), respectively. Hazard ratios for progression-free survival and overall survival were 0.82 (95% CI, 0.53-1.27) and 0.43 (95% CI, 0.19-0.94). These findings support a clinically meaningful benefit of mosunetuzumab monotherapy as a chemotherapy-free option for the 3 L + FL population.

Different patterns of mast cell distribution in B-cell non-Hodgkin lymphomas

Tumor growth, progression, and metastatic capability in non-Hodgkin lymphomas (NHLs) are influenced by different component of tumor microenvironment, including inflammatory cells. Among these latter, mast cells play a crucial role. The spatial distribution of mast cells inside the tumor stroma of different types of B-cell NHLs has not yet been investigated. The aim of this study is to analyze the pattern of distribution of mast cells in biopsy samples obtained from three different types of B-cell NHLs by utilizing an image analysis system and a mathematical model to allow a quantitative estimation to characterize their spatial distribution. As concerns the spatial distributions exhibited by mast cells in diffuse large B cell lymphoma (DLBCL), some clustering was detected in both activated B-like (ABC) and germinal center B-like (GBC) groups. In follicular lymphoma (FL), mast cell spatial distribution tends to uniformly fill the tissue space as far as the grade of the pathology increases. Finally, in marginal lymphoma tissue (MALT) lymphoma, mast cells maintain a significantly clustered spatial distribution, suggesting a lower tendency of the cells to fill the tissue space in this pathological condition. Overall, the data of this study confirm that the analysis of the spatial distribution of the tumor cells is of particular significance for the knowledge of the biological processes occurring in tumor stroma and for the development of parameters to characterize the morphologic organization of the cellular patterns in different types of tumors.

Long Axial Field-of-View PET for Ultra-Low-Dose Imaging of Non-Hodgkin Lymphoma during Pregnancy

Generally, positron emission tomography imaging is not often performed in the case of pregnant patients. The careful weighing of the risks of radiation exposure to the fetus and benefits for cancer staging and the swift onset of treatment for the mother complicates decision making in clinical practice. In oncology, the most commonly used PET radiotracer is 2-deoxy-2-[fluorine-18] fluoro-D-glucose (¹⁸F-FDG), a glucose analog which has established roles in the daily routines for, among other applications, initial diagnosis, staging, (radiation) therapy planning, and response monitoring. The introduction of long axial Field-of-View (LAFOV) PET systems allows for PET imaging with a reduced level of injected ¹⁸F-FDG activity while maintaining the image quality. Here, we discuss the first reported case of a pregnant patient diagnosed with follicular lymphoma using LAFOV PET imaging for the staging and therapy selection. The acquired PET images show diagnostic quality images with clearly distinguishable areas of lymphadenopathy, even with only 34 MBq of injected ¹⁸F-FDG activity, leading to a considerable decrease in the level of radiation exposure to the fetus.

Predicting time to treatment in follicular lymphoma on watchful waiting using baseline metabolic tumour burden

PURPOSE

Asymptomatic patients with follicular lymphoma (FL) and a low tumour burden can be followed without initial therapy, a strategy called watchful waiting (WW). Prediction of the time to treatment (TTT) is still a challenge. We investigated the prognostic value of baseline total metabolic tumour volume (TMTV) and whole-body total lesion glycolysis (WB-TLG) to predict TTT in patients with FL on WW.

METHODS

We conducted a retrospective study of 54 patients with FL (grade 1-3a) diagnosed between June 2013 and December 2019, staged with FDG PET/CT, and managed on WW. Median age was 62 years (range 34-85), stage was advanced (III-IV) in 57%, and FLIPI score was intermediate to high (≥ 2) in 52% of the patients.

RESULTS

The median TMTV and WB-TLG were 7.1 and 43.3, respectively. With a median follow-up of 59 months, 41% of patients started immuno-chemotherapy. The optimal cut-points to identify patients with TTT within 24 months were 14 for TMTV (AUC 0.70; 95% CI 51-88) and 64 for WB-TLG (AUC 0.71; 95% CI 52-89) (p < 0.005). The probability of not having started treatment within 24 months was 87% for TMTV < 14 and 53% for TMTV ≥ 14 (p < 0.005). TMTV was independent of the FLIPI score for TTT prediction. Patients with both FLIPI ≥ 2 and TMTV ≥ 14 had only an 18% probability of not having started treatment at 36 months, while this probability was 75% in patients with TMTV < 14.

CONCLUSION

Metabolic tumour volume parameters may add information to clinical scores to better predict TTT and better stratify patients for interventional studies.

Survival and prognostic analysis of T-cell lymphoblastic lymphoma patients treated with dose-adjusted BFM-90 regimen

We aimed to investigate the long-term prognosis and prognostic factors of T-cell lymphoblastic lymphoma (T-LBL) patients who received dose-adjusted Berlin–Frankfurt–Münster (BFM)-90 regimen as first-line therapy in our center. A total of 145 T-LBL patients who underwent first-line dose-adjusted BFM-90 was retrospectively reviewed. Conditional survival analysis was used to evaluate the long-term prognosis of patients. Receiver operating characteristic (ROC) curve was applied to determine the optimal cut-off value for neutrophil-to-lymphocyte ratio (NLR). Estimated 3-year overall survival (OS) and progression-free survival (PFS) rates for overall were 66.8% and 58.4%, respectively. Conditional survival analysis showed that for patients having survived 3 and 5 years or more after the completion of the treatment, the estimated subsequent 3-year OS thereafter increased to 85.7% and 94.3, respectively. Patients receiving consolidation APBSCT (Autologous peripheral blood stem cell transplantation) after BFM-90 regimen had superior 3-year OS than those with non-APBSCT (79.1% vs. 33.4%, p<0.001). We also discovered that baseline NLR ≥4.95 was negatively associated with OS (HR=2.75, 95% CI 1.55-4.89, p=0.015) and PFS (HR=2.07, 95% CI 1.25-4.96, p=0.021) via multivariable analysis. Conclusions: The survival probability of T-LBL patients treated with first-line dose-adjusted BFM-90 has improved significantly as patients have survived for every additional year. The addition of consolidation APBSCT following dose-adjusted BFM-90 therapy bring further survival benefits for those patients. Baseline NLR ≥4.95 was an independent risk factor for T-LBL patients in our study.

Tumor Microenvironment and Microvascular Density in Follicular Lymphoma

Follicular lymphoma (FL) is a slowly progressive disease and constitutes the second most common non-Hodgkin lymphoma. Biological factors, such as the tumor microenvironment and the host response, are determinants in the outcome of FL but the experimental data about microenvironment and tumor cells in FL are variable and contradictory. In this morphometric study, we analyzed by immunohistochemistry the cellular components of the tumor microenvironment and correlated these data with the microvascular vascular density in three different grades of FL lymph node biopsies, comparing the results to healthy lymph node controls. The results indicated a significant increase in the number of CD68⁺ and CD163⁺ macrophages in all three analyzed FL grades. Tryptase⁺ mast cells resulted in an increase only in grade 1. PDL-1⁺ cells, CD4- and CD8-lymphocytes number results were reduced in FL samples. The higher number of CD34⁺ microvessels in the FL grades 1 and 2 of samples positively correlated with CD68⁺ and CD163⁺ cells, underlining the important angiogenic potential of this subset of macrophages.

A rare face of follicular lymphoma: reverse variant of follicular lymphoma

Background

Reverse Variant of Follicular Lymphoma (RVFL) is one of the rare morphological variants of FL, characterized by dark staining small centrocytes in the center and pale staining large centroblasts at the periphery of the neoplastic follicles. Only rare cases of RVFL have been described to date. The histological appearance of this little known variant of FL may be misinterpreted if pathologists are unaware of its existence. The main purpose of this study is to draw pathologists’ attention to such an uncommon growth pattern of FL so that this variant can be correctly recognized and the clinical significance further studied in the future.

Methods

Four cases of FL with unusual morphologic features were evaluated for the expression pattern of CD20, CD10, BCL6, BCL2, CD21, CD23, CD3, CD5, Cyclin D1, IgD and Ki67 by immunohistochemistry. Fluorescence in situ hybridization (FISH) with break-apart probes was performed to detect BCL2 gene rearrangement.

Results

All four cases showed distinctive morphologic pattern of RVFL; in addition, each also exemplified unique morphological features. Immunohistochemical stains confirmed the cells in both the central areas and the peripheral cuffs had the same immunophenotypic profiles, contrasting to the FL with marginal zone differentiation in which only the center of the nodules showed expression of CD10. FISH demonstrated BCL2 gene rearrangement in all cases.

Conclusion

The growth pattern of this rare FL variant may mimic FL with marginal-zone differentiation and other entities including but not limited to marginal zone lymphoma (MZL), progressive transformation of germinal centers (PTGC) and nodular lymphocyte predominant Hodgkin lymphoma (NLPHL). Pathologists should be familiar with this unusual morphological variant to avoid diagnostic pitfalls.

Morphologic variant of follicular lymphoma reminiscent of hyaline-vascular Castleman disease

Follicular lymphoma (FL) with hyaline-vascular Castleman disease (FL-HVCD)-like features is a rare morphologic variant, with fewer than 20 cases in the literature. Herein, we report a case of FL-HVCD in a 37-year-old female who presented with isolated neck lymph node enlargement. The excised lymph node showed features reminiscent of HVCD, including regressed germinal centers (GCs) surrounded by onion skin-like mantle zones, lollipop lesions composed of hyalinized blood vessels penetrating into regressed GCs, and hyalinized interfollicular stroma. In addition, focal areas of abnormally conglomerated GCs composed of homogeneous, small centrocytes with strong BCL2, CD10, and BCL6 expression were observed, indicating partial involvement of the FL. Several other lymphoid follicles showed features of in situ follicular neoplasia. Based on the observations, a diagnosis of FL-HVCD was made. Although FLHVCD is very rare, the possibility of this variant should be considered in cases resembling CD. Identification of abnormal, neoplastic follicles and ancillary immunostaining are helpful for proper diagnosis.

Obinutuzumab in Combination with Chemotherapy for the First-Line Treatment of Patients with Advanced Follicular Lymphoma : An Evidence Review Group Evaluation of the NICE Single Technology Appraisal

The National Institute for Health and Care Excellence (NICE), as part of the institute's single technology appraisal (STA) process, invited the company that makes obinutuzumab (Roche Products Limited) to submit evidence of the clinical and cost effectiveness of the drug in combination with chemotherapy, with or without obinutuzumab as maintenance therapy for adult patients with untreated, advanced follicular lymphoma (FL) in the UK. Kleijnen Systematic Reviews Ltd (KSR), in collaboration with Erasmus University Rotterdam, was commissioned to act as the Evidence Review Group (ERG). This paper describes the company's submission, the ERG review, and NICE's subsequent decisions. The clinical evidence was derived from two phase III, company-sponsored, randomised, open-label studies. Most evidence on obinutuzumab was based on the GALLIUM trial that compared obinutuzumab in combination with chemotherapy as induction followed by obinutuzumab maintenance monotherapy with rituximab in combination with chemotherapy as induction followed by rituximab maintenance monotherapy in previously untreated patients with FL (grades 1-3a). Long-term clinical evidence was based on the PRIMA trial, studying the benefit of two years of rituximab maintenance after first-line treatment in patients with FL. The cost-effectiveness evidence submitted by the company relied on a partitioned survival cost-utility model, implemented in Microsoft® Excel. The base-case incremental cost-effectiveness ratio (ICER) presented in the company submission was <£20,000 per quality-adjusted life-year (QALY) gained. Although the ERG concluded that the economic model met the NICE reference case to a reasonable extent, some errors were identified and several assumptions made by the company were challenged. A new base-case scenario produced by the ERG suggested an ICER that was higher than the company base case, but still below £30,000 per QALY gained. However, some ERG scenario analyses were close to or even above the threshold. This was the case in particular for assuming a treatment effect that did not extend beyond trial follow-up. These results led to an initial negative recommendation by the appraisal committee. Subsequently, the company submitted a revised base case focusing on patients at intermediate or high risk of premature mortality. Simultaneously, a further price discount for obinutuzumab was granted. In addition to the company's revised base case, the ERG suggested a restriction of the treatment effect to 5 years and implemented biosimilar uptake and cheaper prices for rituximab. All of these adjustments did not exceed £30,000 per QALY gained and therefore the use of obinutuzumab for patients with advanced FL and a Follicular Lymphoma International Predictive Index (FLIPI) score of two or more could be recommended.

Additional therapy improves outcomes in completely resected, limited-stage follicular lymphoma

Patients with early-stage nodal follicular lymphoma (FL) may be rendered free of detectable disease by a diagnostic excisional biopsy. We reviewed the management and outcomes of 48 patients with FL, diagnosed from 2003-2013, treated at a single institution. The primary endpoints were local control (LC) and progression-free survival (PFS).Median age at diagnosis was 54.5 years (range 15-74 years). Forty-seven patients were stage I (97.9%); 15 patients (31.3%) had grade 3 disease. Initial management consisted of observation (12 patients; 25.0%), radiation therapy (RT) alone (12 patients; 25.0%), systemic therapy alone (9 cases; 18.8%), or both (15 patients; 31.3%). Median follow-up was 4.92 years (range 0.5-13.83 years). 4-year PFS and OS were 80.9% and 97.1%, respectively. Patients treated with additional therapy experienced significantly better 4-year LC (100% vs. 81.8%; p = .012) and 4-year PFS (86.7% vs. 63.6%; p = .006).Patients with completely resected limited-stage FL would benefit from therapy beyond excisional biopsy alone.

Treatment Patterns and Survival Outcomes in Patients With Follicular Lymphoma: A 2007 to 2015 Humedica Database Study

BACKGROUND

Few studies have evaluated real-world treatment patterns and survival in follicular lymphoma (FL). This study evaluated these outcomes among newly diagnosed patients with FL in routine clinical care.

PATIENTS AND METHODS

A retrospective study was conducted in newly diagnosed patients with FL from Humedica, a large United States electronic medical record database, from January 1, 2008 to July 31, 2015. Patients were followed from treatment initiation until death, loss to follow-up, or end of study (September 30, 2015). Treatment patterns were assessed in the follow-up period. Progression-free survival (PFS) and overall survival (OS) at 2 years were evaluated in the overall population using Kaplan-Meier analyses. OS was also compared between patients with and without evidence of disease progression within 2 years following first-line therapy (ie, early progressors vs. non-early progressors).

RESULTS

A total of 1346 patients were included in the study, with most patients receiving rituximab-based regimens. Fewer early progressors received rituximab-based regimens. Across all lines, combination therapies predominated, particularly bendamustine + rituximab. Following first-line therapy, OS was 86.9% at 2 years, and median OS was not reached. Two-year PFS after first-line therapy was 64.6%, and median PFS was 48.1 months (95% confidence interval, 39.4-58.4 months). OS at 2 years was 76.8% among early progressors versus 90.4% among non-early progressors (P < .001); the median OS was not reached in both groups.

CONCLUSION

In routine clinical practice, rituximab-based regimens predominated; however, utilization of these regimens differed among early and non-early progressors. The assessment of survival outcomes also highlights the negative impact of early progression on OS in the rituximab-era.

Tolerability of obinutuzumab therapy in patients with rituximab-relapsed/refractory B-cell malignancies - a retrospective single center cohort study

BACKGROUND & AIM

In randomised clinical trials, the type II anti-CD20 antibody obinutuzumab has been shown to be more effective than rituximab for therapy of chronic lymphocytic leukemia (CLL) and follicular lymphoma (FL). However, this enhanced efficacy was linked with elevated rates of high-grade adverse events. The aim of this study was to assess the tolerability and toxicity profile of obinutuzumab treatment in routine patients with CLL and FL, of whom the majority had experienced toxicity or resistance to rituximab.

METHODS

This retrospective cohort study investigated fifteen obinutuzumab-treated patients, eight with CLL and seven with FL. The course of the disease, comorbidities and treatment-related toxicities were recorded. All patients with CLL and all but three FL patients had any form of pre-treatment with rituximab.

RESULTS

Between October 2014 and August 2017, 15 patients were treated with obinutuzumab at the University Hospital Krems. In the CLL-cohort, 1 patient (12,5%) developed pneumonia, 2 (25%) febrile neutropenia, 6 (75%) anemia and 7 (87,5%) thrombocytopenia, respectively. One patient exhibited an infusion-related allergic reaction. In the FL-cohort, 6 patients (85,7%) presented with thrombocytopenia, 3 (42,9%) with anemia and one patient with neutropenia. No sepsis or consecutive solid tumors were seen in any of the patients.

CONCLUSION

Obinutuzumab was mostly well tolerated in mild to heavily pre-treated patients with CLL and therapy-naïve or pre-treated patients with FL. The frequency and profile of adverse events and toxicity was comparable to data from previous clinical studies and could be managed adequately in the setting of a University Clinic.

Efficacy of Idelalisib as Bridge to Allogeneic Stem Cell Transplant in Relapsed Follicular Lymphoma: A Case Report

Purpose

A large number of new therapeutic agents have been studied for patients with relapsed/refractory follicular lymphoma (FL). Among new therapies, idelalisib, a novel PI3K inhibitor, shows promising results in the management of this disease.

Case report

We describe the case of a 39-year-old patient with a diagnosis of grade 3a FL and a Follicular Lymphoma International Prognostic Index score of 2, who underwent several lines of therapy (including autologous stem cell transplant) with transient responses or no response at all. The patient was subsequently treated with 5 courses of idelalisib monotherapy, achieving a partial response. No relevant toxicities occurred. The patient underwent allogeneic stem cell transplant (allo-SCT) from an unrelated donor and obtained a complete response, which was confirmed after 3, 6, 9, and 12 months, and is still ongoing.

Conclusions

As previously reported, the achievement of a good response is predictive for a better outcome after allo-SCT: idelalisib represents an effective treatment option for patients with relapsed/refractory FL, which can also be adopted as a bridge to allo-SCT.

Economic burden of patients with diffuse large B-cell and follicular lymphoma treated in the USA

AIM

Evaluate healthcare costs and utilization of treated diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL) patients.

MATERIALS & METHODS

Adults with newly diagnosed DLBCL and FL between 1 January 2008 and 31 October 2015 were identified in the Optum™ claims database. Healthcare costs and utilization were assessed from diagnosis date until end of follow-up.

RESULTS

A total of 1267 DLBCL- and 1595 FL-treated patients were identified. Mean per-patient, per-month cost during follow-up was US$11,890 for DLBCL and US$10,460 for FL. Healthcare costs and utilization decreased from year 1 to 2 following diagnosis, due to a decrease in chemotherapy services, inpatient admissions and other outpatient services.

CONCLUSION

The economic burden of treated DLBCL and FL is considerable, especially in the first year following diagnosis.

Follicular lymphoma with hyaline-vascular Castleman-like features: analysis of 6 cases and review of the literature

Follicular lymphoma (FL) with features reminiscent of hyaline-vascular Castleman disease (CD) is an unusual morphologic variant that may create diagnostic difficulties. To our knowledge, only 5 cases of this variant have been reported. We describe the clinicopathologic features of 6 cases including 2 men and 4 women with a median age of 63 years (range, 41-77). Morphologically, all lymph node biopsy specimens showed at least a focal area of conventional FL; 4 cases showed neoplastic follicles with hyalinized blood vessels penetrating into germinal centers (lollipop-like lesions); 4 cases had interfollicular areas with increased vascular stroma; 2 cases showed small neoplastic follicles with prominent, onionskin-like mantle zones; and 1 case showed 2 or more germinal centers within follicles (twinning). The small neoplastic follicles were more cellular than lymphocyte-depleted follicles of true hyaline-vascular CD, and the interface between germinal centers and mantle zones was ill defined. No cases showed dysplastic follicular dendritic cells. Immunohistochemistry for BCL-2 was positive in all 6 cases. Flow cytometry immunophenotypic analysis showed a monotypic B-cell population in 2 of 3 cases assessed. Conventional cytogenetic or fluorescence in situ hybridization studies performed in 3 cases showed t(14;18)(q32;q21) or IGH-BCL2, supporting the diagnosis of FL. The cases presented here add clinicopathologic data to the few cases of FL with hyaline-vascular CD-like features reported previously in the literature. Distinguishing this variant of FL from hyaline-vascular CD is important given the differences in treatment and prognosis of patients with each disease.

Drug discovery and therapeutic delivery for the treatment of B and T cell tumors

Hematological malignancies manifest as lymphoma, leukemia, and myeloma, and remain a burden on society. From initial therapy to endless relapse-related treatment, societal burden is felt not only in the context of healthcare cost, but also in the compromised quality of life of patients. Long-term therapeutic strategies have become the standard in keeping hematological malignancies at bay as these cancers develop resistance to each round of therapy with time. As a result, there is a continual need for the development of new drugs to combat resistant disease in order to prolong patient life, if not to produce a cure. This review aims to summarize advances in targeting lymphoma, leukemia, and myeloma through both cutting-edge and well established platforms. Current standard of treatment will be reviewed for these malignancies and emphasis will be made on new therapy development in the areas of antibody engineering, epigenetic small molecule inhibiting drugs, vaccine development, and chimeric antigen receptor cell engineering. In addition, platforms for the delivery of these and other drugs will be reviewed including antibody-drug conjugates, micro- and nanoparticles, and multimodal hydrogels. Lastly, we propose that tissue engineered constructs for hematological malignancies are the missing link in targeted drug discovery alongside mouse and patient-derived xenograft models.

Follicular lymphoma of the caecum resected endoscopically

Colorectal follicular lymphomas, primary or secondary, are rare. Magnifying endoscopy with narrow-band imaging is useful in the diagnosis of colorectal follicular lymphoma. In addition, immunohistochemistry is essential in differentiating follicular lymphoma cells from lymphoid follicle hyperplasia based on the presence of Bcl-2 expression. We herein report a rare case of follicular lymphoma of the caecum, presenting as a small polyp that was resected endoscopically.

Double-hit follicular lymphoma with MYC and BCL2 translocations: a study of 7 cases with a review of literature

Follicular lymphoma with MYC and BCL2 translocations, so-called double-hit follicular lymphoma (DH-FL), is rare. Here, we report the clinicopathological features of 7 cases of DH-FL. All neoplasms had a follicular pattern (1 partially diffuse). Five cases were predominantly low grade, 4 of which had focal (≤20%) grade 3A areas, and 2 cases were of grade 3. All cases were positive for pan-B-cell antigens, CD10, and BCL6; 6 cases were positive for BCL2. Ki-67 was less than or equal to 50% in 6 cases and 90% in 1 grade 3 case. Three patients presented with stage IV disease and 3 had a Follicular Lymphoma International Prognostic Index score of greater than 2. Six patients received immunochemotherapy, and 1 is still under induction therapy with rituximab, ibrutinib, and lenalidomide. Four achieved complete remission and two had a partial response with persistent or refractory disease. The median follow-up time was 25 months (range, 8.5-53.7 months). Two patients treated with standard regimen for follicular lymphoma had relapsed or refractory disease, and 1 died from complications of allogeneic stem cell transplant administered for relapse. In contrast, all 4 patients treated with more intensive regimen for double-hit lymphoma achieved complete remission. In summary, despite predominantly low-grade histology, cases of DH-FL in this study were aggressive and responded better to more intensive than standard treatment regimens, suggesting DH-FL is part of the spectrum of double-hit high-grade lymphoma.

Anti-CD20 antibody treatment of non-Hodgkin lymphomas

The CD20 antigen characteristic for mature B-cell is also expressed on B-cell Non-Hodgkin lymphomas (NHL). It thus presents a possible target for immunotherapy. NHL respond readily to radio- and/or chemotherapy but this standard treatment bears a high risk of relapse. The specific monoclonal anti-CD20-antibody Rituximab, the first to be approved for clinical use, could be shown to improve response rates, response duration, and survival in NHL when combined with standard therapy. This review details the development, clinical application, and future perspectives of anti-CD20-antibody treatment of NHL, thereby proving the efficiency of immunotherapy via targeting of a tumor associated antigen.