Rituximab in newly diagnosed stage IA nodular lymphocyte-predominant Hodgkin lymphoma: long-term follow-up of a phase 2 study from the German Hodgkin Study Group

Nodular lymphocyte-predominant Hodgkin lymphoma revisited: current management strategies and future perspectives

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare lymphoma entity accounting for ≈5% of all Hodgkin lymphoma (HL) cases. As some characteristics of NLPHL resemble B-cell non-Hodgkin lymphoma (B-NHL), nodular lymphocyte-predominant B-cell lymphoma has been proposed as alternative name. Unlike classical HL (cHL), NLPHL is mostly diagnosed in early stages. The clinical course is usually indolent. Overall, NLPHL patients have an excellent prognosis and the majority experiences long-term survival. Except for stage IA disease which is sufficiently treated with radiotherapy alone, treatment of newly diagnosed NLPHL is often very similar to cHL. However, activity has also been demonstrated for rituximab-containing protocols applied in B-NHL. Second-line treatment is chosen individually and mostly less intensive than in cHL. Chimeric antigen receptor T-cell therapy and bispecific antibodies may be part of future treatment strategies for NLPHL. This review aims at summarizing recent data on treatment approaches and discussing future perspectives in NLPHL.

Nodular lymphocyte-predominant Hodgkin lymphoma: current management strategies and evolving approaches to individualize treatment

INTRODUCTION

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare lymphoma entity accounting for roughly 5% of all Hodgkin lymphoma (HL) cases. In contrast to classical HL, the malignant cells in NLPHL are positive for CD20 but lack CD30. The disease usually has an indolent clinical course resulting in high long-term survival rates.

AREAS COVERED

In this review, treatment options for NLPHL are summarized and factors that may help to individualize treatment are discussed.

EXPERT OPINION

Stage IA NLPHL without clinical risk factors should be treated with limited-field radiotherapy alone. In all other stages, NLPHL patients have excellent outcomes after standard HL approaches. The question of whether the addition of an anti-CD20 antibody to standard HL chemotherapy protocols or the use of approaches typically applied in B-cell non-Hodgkin lymphoma improve treatment results is unanswered until now. Different management strategies ranging from low-intensity treatment to high-dose chemotherapy and autologous stem cell transplantation have demonstrated activity in relapsed NLPHL. Second-line treatment is thus chosen individually. The major aim of NLPHL research is to spare toxicity and reduce the risk for treatment-related adverse events in low-risk patients while treating higher-risk patients with appropriate intensity. To this end, novel tools to guide treatment are required.

Treatment of Nodular Lymphocyte-Predominant Hodgkin Lymphoma: Where Do We Stand? Where Do We Go?

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare B cell-derived lymphoma entity accounting for ≈5% of all Hodgkin lymphoma (HL) cases. In recent decades, patients with newly diagnosed NLPHL have usually been treated very similarly to classical HL (cHL). The 10-year overall survival rates with HL-directed approaches are in excess of 90%. However, pathological and clinical characteristics of NLPHL resemble indolent B-cell non-Hodgkin lymphoma (B-NHL) in some aspects. Thus, nodular lymphocyte-predominant B-cell lymphoma has been proposed as an alternative name, and the use of B-NHL-directed treatment strategies has become more common in NLPHL despite limited data. Given the often indolent clinical course of NLPHL, even in the case of relapse, the majority of patients with disease recurrence do not require high-dose chemotherapy and autologous stem cell transplantation but are treated sufficiently with low-intensity approaches such as single-agent anti-CD20 antibody treatment. The establishment of novel prognostic scores for NLPHL patients may optimize risk group and treatment allocation in newly diagnosed and relapsed disease.

Individualized patient care in nodular lymphocyte-predominant Hodgkin lymphoma

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare lymphoma that has traditionally been considered a subgroup of Hodgkin lymphoma. However, morphology, surface marker expression, genetics, and clinical course are different from classic Hodgkin lymphoma. While most patients experience indolent disease with slow progression, some patients can also have more aggressive disease. Nevertheless, outcomes are excellent, and excess mortality due to NLPHL is at most very low. The treatment of newly diagnosed NLPHL has historically mirrored that of classic Hodgkin lymphoma. However, evidence for deviations from that approach has emerged over time and is discussed herein. Less evidence is available for the optimal management of relapsed patients. So-called variant histology has recently emerged as a biological risk factor, providing at least a partial explanation for the observed heterogeneity of NLPHL. Considering variant histology together with other risk factors and careful observation of the clinical course of the disease in each patient can help to assess individual disease aggressiveness. Also important in this mostly indolent disease are the preferences of the patient and host factors, such as individual susceptibility to specific treatment side effects. Considering all this together can guide individualized treatment recommendations, which are paramount in this rare disease.

Outcome of limited-stage nodular lymphocyte-predominant Hodgkin lymphoma and the impact of a PET-adapted approach

Radiotherapy (RT) is typically incorporated into the treatment of limited-stage nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL), although it remains unknown whether chemotherapy alone may be suitable in select patients. We evaluated outcomes of limited-stage NLPHL at BC Cancer on the basis of era-specific guidelines: routine RT era, 1995 to 2005 (n = 36), combined modality with 2 cycles of doxorubicin, bleomycin, vinblastine, dacarbazine (ABVD) chemotherapy followed by RT or RT alone; positron emission tomography (PET) era, after 2005 (n = 63), ABVD alone (4 cycles) if the PET scan after the second cycle of ABVD (PET2) is negative, or treatment is changed to RT if PET2 is positive. Median age of patients was 38 years (range, 16-82 years), 73% were male, and 43% had stage II. With a median follow-up of 10.5 years for all patients, 5-year progression-free survival (PFS) was 91% [corrected] and was 97% for overall survival (OS), with no difference by treatment era (PFS, P = .15; [corrected] OS, P = .35). For the 49 patients who had a PET2 scan, 86% were PET negative and 14% were PET positive by Deauville criteria with 5-year PFS rates of 92% and 80% (P = .87) [corrected], respectively. This is the largest study of a PET-adapted approach in NLPHL and supports that ABVD alone may be a viable option in select patients with a negative PET2 scan, with consideration of acute and long-term toxicities.

Current treatment options for nodular lymphocyte-predominant Hodgkin lymphoma

PURPOSE OF REVIEW

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare B cell-derived malignancy. This review aims at providing an overview of recent developments in the management of NLPHL.

RECENT FINDINGS

Patients with stage IA NLPHL without risk factors have excellent outcomes. The 8-year progression-free survival (PFS) is roughly 90% and the 8-year overall survival (OS) close to 100% after limited-field radiotherapy (RT) alone. Individuals presenting with early stages other than stage IA without risk factors and intermediate stages have 10-year PFS rates in excess of 70% and 10-year OS rates exceeding 90% when treated with 2 and 4 cycles of ABVD, respectively, followed by consolidation RT. In advanced NLPHL, different protocols such as BEACOPP, ABVD, and R-CHOP have been evaluated retrospectively. However, the optimal approach is undefined. Patients with relapsed NLPHL mostly receive single-agent anti-CD20 antibody treatment or conventional chemotherapy. High-dose chemotherapy and autologous stem cell transplantation are restricted to high-risk patients. NLPHL recurrence is salvaged successfully in the majority of cases.

SUMMARY

Patients with NLPHL have a very good prognosis. Treatment differs from classical Hodgkin lymphoma in some situations.

Outcome of relapsed and refractory nodular lymphocyte-predominant Hodgkin lymphoma: a North American analysis

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare entity, with limited data on the outcome in the relapsed/refractory setting. We evaluated the outcome of all patients diagnosed between 04/1979 and 01/2019 with relapsed or progressive NLPHL after initial active therapy at two institutions, refractory disease being defined as lack of response to treatment and/or relapse within three months of treatment. NLPHL patients with histological evidence of transformation at time of first relapse or progression were excluded. In total, 69 patients with recurrent NLPHL were included in the study. After a median follow-up after initial diagnosis of 14 years (range, 0·5-46 years), median progression-free survival after front-line treatment (PFS-1) was four years. Second-line therapy included chemotherapy in 28 (41%) patients, biological therapy (rituximab, lenalidomide or brentuximab vedotin) in 14 (20%), high-dose chemotherapy followed by autologous stem cell transplant in 14 (20%) and radiation therapy (RT) alone in 10 (15%). The five-year PFS after second-line therapy (PFS-2) was 68% [95% confidence interval (CI), 54-79%] but the five-year overall survival (OS) after second-line therapy (OS-2) remained excellent, at 94% (95% CI, 85-99%). Due to excellent outcome in case of recurrence, studies aimed at characterizing its biology to guide therapy de-escalation are needed.

Rituximab-Containing Risk-Adapted Treatment Strategy in Nodular Lymphocyte Predominant Hodgkin Lymphoma: 7-Years Follow-Up

BACKGROUND

Nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) is a rare variant of HL that accounts for 5% of all HL cases. The expression of CD20 on neoplastic lymphocytes provides a suitable target for novel treatments based on Rituximab. Due to its rarity, consolidated and widely accepted treatment guidelines are still lacking for this disease.

METHODS

Between 1 December 2007 and 28 February 2018, sixteen consecutive newly diagnosed adult patients with NLPHL received Rituximab (induction ± maintenance)-based therapy, according to the baseline risk of German Hodgkin Study Group prognostic score system. The treatment efficacy and safety of the Rituximab-group were compared to those of a historical cohort of 12 patients with NLPHL who received Doxorubicin, Bleomycin, Vinblastine, Dacarbazine (ABVD) chemotherapy followed by radiotherapy (RT), if needed, according to a similar baseline risk. The primary outcome was progression-free survival (PFS) and secondary outcomes were overall survival (OS) and side-effects (according to the Common Terminology Criteria for Adverse Events, v4.03).

RESULTS

After a 7-year follow-up (range, 1-11 years), PFS was 100% for patients treated with the Rituximab-containing regimen versus 66% for patients of the historical cohort (p = 0.036). Four patients in the latter group showed insufficient response to therapy. The PFS for early favorable and early unfavorable NLPHLs was similar between treatment groups, while a better PFS was recorded for advanced-stages treated with the Rituximab-containing regimen. The OS was similar for the two treatment groups. Short- and long-term side-effects were more frequently observed in the historical cohort. Grade ≥3 neutropenia was more frequent in the historical cohort compared with the Rituximab-group (58.3% vs. 18.7%, respectively; p = 0.03). Long-term non-hematological toxicities were observed more frequently in the historical cohort.

CONCLUSION

Our results confirm the value of Rituximab in NLPHL therapy and show that Rituximab (single-agent) induction and maintenance in a limited-stage, or Rituximab with ABVD only in the presence of risk factors, give excellent results while sparing cytotoxic agent- and/or RT-related damage. Furthermore, Rituximab inclusion in advanced-stage therapeutic strategy seems to improve PFS compared to conventional chemo-radiotherapy.

Stage I-II nodular lymphocyte-predominant Hodgkin lymphoma: a multi-institutional study of adult patients by ILROG

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is an uncommon histologic variant, and the optimal treatment of stage I-II NLPHL is undefined. We conducted a multicenter retrospective study including patients ≥16 years of age with stage I-II NLPHL diagnosed from 1995 through 2018 who underwent all forms of management, including radiotherapy (RT), combined modality therapy (CMT; RT+chemotherapy [CT]), CT, observation after excision, rituximab and RT, and single-agent rituximab. End points were progression-free survival (PFS), freedom from transformation, and overall survival (OS) without statistical comparison between management groups. We identified 559 patients with median age of 39 years: 72.3% were men, and 54.9% had stage I disease. Median follow-up was 5.5 years (interquartile range, 3.1-10.1). Five-year PFS and OS in the entire cohort were 87.1% and 98.3%, respectively. Primary management was RT alone (n = 257; 46.0%), CMT (n = 184; 32.9%), CT alone (n = 47; 8.4%), observation (n = 37; 6.6%), rituximab and RT (n = 19; 3.4%), and rituximab alone (n = 15; 2.7%). The 5-year PFS rates were 91.1% after RT, 90.5% after CMT, 77.8% after CT, 73.5% after observation, 80.8% after rituximab and RT, and 38.5% after rituximab alone. In the RT cohort, but not the CMT cohort, variant immunoarchitectural pattern and number of sites >2 were associated with worse PFS (P < .05). Overall, 21 patients (3.8%) developed large-cell transformation, with a significantly higher transformation rate in those with variant immunoarchitectural pattern (P = .049) and number of involved sites >2 (P = .0006). OS for patients with stage I-II NLPHL was excellent after all treatments.

How I treat nodular lymphocyte-predominant Hodgkin lymphoma

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare lymphoma entity with distinct pathologic and clinical characteristics. Unlike the malignant cells in classical Hodgkin lymphoma, the disease-defining lymphocyte-predominant cells in NLPHL are consistently positive for CD20, but do not express CD30. The clinical course of NLPHL is indolent in the majority of cases. Most patients present with early-stage disease at the initial diagnosis. First-line treatment of stage IA NLPHL usually consists of limited-field radiotherapy alone. Patients with early-stage NLPHL other than stage IA and intermediate-stage disease mostly receive combined-modality treatment, whereas individuals with advanced NLPHL are treated with chemotherapy alone. In relapsed NLPHL, conventional chemotherapy, anti-CD20 antibodies, and radiotherapy represent active treatment modalities. Only patients with poor-risk characteristics such as early disease recurrence are candidates for aggressive salvage treatment with high-dose chemotherapy and autologous stem cell transplantation. The overall and relative survival of patients with NLPHL is excellent as indicated by a low excess mortality compared with the general population. This article discusses treatment options for patients with NLPHL and factors that influence the choice of therapy on the basis of the available data and 2 clinical cases.

Lymphocyte predominant Hodgkin lymphoma, antigen-driven after all?

Nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) was suggested as an entity separate from other types of Hodgkin lymphoma 40 years ago and recognized in the WHO classification in 2001. Based on its relatively benign course with late distant relapses, relation with lymph node hyperplasia with progressively transformed germinal centers, presence of clonal immunoglobulin gene rearrangements with somatic hypermutations and ongoing mutations, and relation with a number of inherited defects affecting the immune system, it has been suspected that NLPHL might be antigen-driven. Recent evidence has shown that cases of IgD-positive NLPHL are associated with infection by Moraxella catarrhalis, a common bacterium in the upper respiratory tract and in lymph nodes. This review summarizes the evidence for NLPHL as a B-cell lymphoma involving follicular T-lymphocytes normally found in germinal centers, its molecular features and relation to inherited immune defects, and its relation and differential diagnosis from similar entities. Finally, it discusses the evidence that in many cases a watch and wait policy might be a viable initial management strategy. © 2020 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.