The potential benefit of allogeneic over autologous transplantation in patients with very early relapsed and refractory follicular lymphoma with prior remission duration of ≤12 months

Clinical Practice Recommendations for Hematopoietic Cell Transplantation and Cellular Therapies in Follicular Lymphoma: A Collaborative Effort on Behalf of the American Society for Transplantation and Cellular Therapy and the European Society for Blood and Marrow Transplantation

Follicular lymphoma (FL) is the most common indolent B-cell non-Hodgkin lymphoma (NHL), accounting for nearly one-third of all NHL. The therapeutic landscape for patients with FL has significantly expanded over the past decade, but the disease continues to be considered incurable. Hematopoietic cell transplantation (HCT) is potentially curative in some cases. Recently, the emergence of chimeric antigen receptor T-cell therapy (CAR-T) for patients with relapsed/refractory (R/R) FL has yielded impressive response rates and long-term remissions, but definitive statement on the curative potential of CAR-T is currently not possible due to limited patient numbers and relatively short follow up. A consensus on the contemporary role, optimal timing, and sequencing of HCT (autologous or allogeneic) and cellular therapies in FL is needed. As a result, the American Society of Transplantation and Cellular Therapy (ASTCT) Committee on Practice Guidelines endorsed this effort to formulate consensus recommendations to address this unmet need. The RAND-modified Delphi method was used to generate 15 consensus statements/recommendations. These clinical practice recommendations will help guide clinicians managing patients with FL. Of note, the use of bispecific antibodies in R/R FL was not in the scope of this project.

Clinical outcomes in patients relapsed/refractory after ≥2 prior lines of therapy for follicular lymphoma: a systematic literature review and meta-analysis

BACKGROUND

Patients with follicular lymphoma (FL) can have high response rates to early lines of treatment. However, among FL patients relapsed/refractory (r/r) after ≥2 prior lines of therapy (LOT), remission tends to be shorter and there is limited treatment guidance. This study sought to evaluate the clinical outcomes for r/r FL after ≥2 prior LOT identified through systematic literature review.

METHODS

Eligible studies included comparative or non-comparative interventional or observational studies of systemic therapies among adults with FL r/r after ≥2 prior LOT published prior to 31st May 2021. Prior LOT must have included an anti-CD20 monoclonal antibody and an alkylating agent, in combination or separately. Overall response rate (ORR) and complete response (CR) were estimated using inverse-variance weighting with Freeman-Tukey double-arcsine transformations. Kaplan-Meier (KM) curves for progression-free survival (PFS) and overall survival (OS) estimated by reconstructing digitized curves using the Guyot algorithm, and survival analyses were conducted, stratified by ≥2 prior LOT and ≥ 3 prior LOT groups (as defined in the source material). Restricting the analyses to the observational cohorts was investigated as a sensitivity analysis.

RESULTS

The analysis-set included 20 studies published between 2014 and 2021. Studies were primarily US and/or European based, with the few exceptions using treatments approved in US/Europe. The estimated ORR was 58.47% (95% confidence interval [CI]: 51.13-65.62) and proportion of patients with CR was 19.63% (95% CI: 15.02-24.68). The median OS among those ≥2 prior LOT was 56.57 months (95% CI: 47.8-68.78) and median PFS was 9.78 months (95% CI: 9.01-10.63). The 24-month OS decreased from 66.50% in the ≥2 prior LOT group to 59.51% in the ≥3 prior LOT group, with a similar trend in PFS at 24-month (28.42% vs 24.13%).

CONCLUSIONS

This study found that few r/r FL patients with ≥2 prior LOT achieve CR, and despite some benefit, approximately 1/3 of treated patients die within 24 months. The shorter median PFS with increasing prior LOT suggest treatment durability is suboptimal in later LOT. These findings indicate that patients are underserved by treatments currently available in the US and Europe.

Comparison of Survival Between Autologous and Allogeneic Stem Cell Transplantation in Patients with Relapsed or Refractory B-Cell Non-Hodgkin Lymphoma: A Meta-Analysis

This study aimed to compare the efficacy of allogeneic stem cell transplantation (allo-SCT) versus autologous SCT (auto-SCT) in patients with relapsed or refractory B-cell non-Hodgkin lymphoma (B-NHL). Medline, CENTRAL, and EMBASE databases through December 31, 2019 were searched. The primary endpoints were overall survival (OS) and progression-free survival (PFS) rates. The secondary outcomes include transplant-related mortality (TRM), event-free survival, relapse/or progression, and nonrelapse mortality (NRM). The 18 retrospective studies enrolled 8,058 B-NHL patients (allo-SCT = 1,204; auto-SCT = 6,854). The OS was significantly higher in patients receiving auto-SCT than allo-SCT (pooled odds ratio [OR]: 1.69, 95% confidence interval [CI]: 1.29 to 2.22, P < 0.001), but no significant difference was found in PFS (pooled OR: 0.98, 95% CI: 0.69 to 1.38, P = 0.891). Auto-SCT patients also had lower TRM and NRM (TRM: OR = 0.23, P < 0.001; NRM: OR = 0.16, P < 0.001), but higher relapse or progression rate (OR = 2.37, P < 0.001) than allo-SCT patients. Subgroup analysis performed for different grades and subtypes of B-NHL showed higher OS in auto-SCT patients with high-grade B-NHL and diffused large B-cell lymphoma (DLBCL). There was, nevertheless, higher PFS in allo-SCT patients with low-grade B-NHL and follicular lymphoma (FL), and lower PFS in allo-SCT patients with DLBCL than their auto-SCT counterparts. In conclusion, the meta-analysis demonstrated that relapsed or refractory B-NHL patients who received auto-SCT have improved OS than those treated with allo-SCT, especially among those with DLBCL, but lower PFS among those with FL. However, the study is limited by a lack of randomized trials, patients’ heterogeneity, and possible selection bias.

Precision medicine in follicular lymphoma: Focus on predictive biomarkers

Current care for patients with follicular lymphoma (FL) offers most of them long-term survival. Improving it further will require careful patient selection. This review focuses on predictive biomarkers (ie, those whose outcome correlations depend on the treatment strategy) in FL, because awareness of what patient subsets benefit most or least from each therapy will help in this task. The first part of this review aims to summarize what biomarkers are predictive in FL, the magnitude of the effect and the quality of the evidence. We find predictive biomarkers in the setting of (a) indication of active treatment, (b) front-line induction (use of anthracyline-based regimens, CHOP vs bendamustine, addition of rituximab), (c) post-(front-line)induction (rituximab maintenance, radioimmunotherapy), and (d) relapse (hematopoietic stem cell transplant) and targeted agents. The second part of this review discusses the challenges of precision medicine in FL, including (a) cost, (b) clinical relevance considerations, and (c) difficulties over the broad implementation of biomarkers. We then provide our view on what biomarkers may become used in the next few years. We conclude by underscoring the importance of assessing the potential predictiveness of available biomarkers to improve patient care but also that there is a long road ahead before reaching their broad implementation due to remaining scientific, technological, and economic hurdles.

Follicular lymphoma: Update on management and emerging therapies at the dawn of the new decade

Follicular lymphoma is the most common indolent non-Hodgkin lymphoma. Survival has improved over the last several decades, mainly because of the incorporation of the anti-CD20 antibody rituximab into preexisting or rediscovered agents. The disease has a relapsing and remitting pattern, coupled with a risk of transformation into an aggressive lymphoma, and considered incurable for most patients. Next-generation sequencing technologies have increased our understanding of the biology and genetic landscape of the disease, identifying potential druggable targets for treatment. Current prognostic models cannot accurately identify patients at risk of early progression and despite the availability of treatment options for relapsed/refractory disease, rational treatment selection balancing disease control, efficacy with toxicity, and quality of life remain unmet needs. This review provides an overview of biology, prognostication, treatment options, and emerging therapies that provide valid grounds for optimism.

Autologous transplantation versus allogeneic transplantation in patients with follicular lymphoma experiencing early treatment failure

BACKGROUND

Early treatment failure (ETF) in follicular lymphoma (FL), defined as relapse or progression within 2 years of frontline chemoimmunotherapy, is a newly recognized marker of poor survival and identifies a high-risk group of patients with an expected 5-year overall survival (OS) rate of approximately 50%. Transplantation is an established option for relapsed FL, but its efficacy in this specific ETF FL population has not been previously evaluated.

METHODS

This study compared autologous hematopoietic stem cell transplantation (auto-HCT) with either matched sibling donor (MSD) or matched unrelated donor (MUD) allogeneic hematopoietic cell transplantation (allo-HCT) as the first transplantation approach for patients with ETF FL (age ≥ 18 years) undergoing auto-HCT or allo-HCT between 2002 and 2014. The primary endpoint was OS. The secondary endpoints were progression-free survival, relapse, and nonrelapse mortality (NRM).

RESULTS

Four hundred forty FL patients had ETF (auto-HCT, 240; MSD hematopoietic stem cell transplantation [HCT], 105; and MUD HCT, 95). With a median follow-up of 69 to 73 months, the adjusted probability of 5-year OS was significantly higher after auto-HCT (70%) or MSD HCT (73%) versus MUD HCT (49%; P = .0008). The 5-year adjusted probability of NRM was significantly lower for auto-HCT (5%) versus MSD (17%) or MUD HCT (33%; P < .0001). The 5-year adjusted probability of disease relapse was lower with MSD (31%) or MUD HCT (23%) versus auto-HCT (58%; P < .0001).

CONCLUSIONS

Patients with high-risk FL, as defined by ETF, undergoing auto-HCT for FL have low NRM and a promising 5-year OS rate (70%). MSD HCT has lower relapse rates than auto-HCT but similar OS. Cancer 2018;124:2541-51. © 2018 American Cancer Society.

[Allogeneic haematopoietic cell transplantation for indolent lymphomas: Guidelines from the Francophone Society Bone Marrow Transplantation and Cellular Therapy (SFGM-TC)]

Despite great improvements in the outcome of patients with lymphoma, some may still relapse or present with primary refractory disease. In these situations, allogeneic hematopoietic cell transplantation is a potentially curative option, this is true particularly the case of relapse after autologous stem cell transplantation. Recently, novel agents such as anti-PD1 and BTK inhibitors have started to challenge the use of allogeneic hematopoietic cell transplantation for relapsed or refractory lymphoma. During the 2016 annual workshop of the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC), we performed a comprehensive review of the literature published in the last 10 years and established guidelines to clarify the indications and transplant modalities in this setting. This paper specifically reports on our conclusions regarding indolent lymphomas, mainly follicular lymphoma and chronic lymphocytic leukemia.

The role of stem cell transplantation in follicular lymphoma

With the introduction of novel treatments paradigms to if or when to use transplantation strategies for patients with follicular lymphoma have changed substantially. Autologous transplantation has been intensively evaluated as consolidation after first induction treatment with positive effects, however the introduction of Rituximab led to comparable improvements and HDT has been moved to relapse treatment. In this indication HDT was frequently use already at first relapse, but now is dominantly used in patients with a highrisk profile, e.g. failure of response, early or multiply relapse and/or signs of transformation. The ideal place for allogeneic transplantation is even harder to define, as the curative potential might be outweighed by the substantial side effect profile and the indication must always be discussed in the light of available alternatives. In consequence, transplantation strategies remain an important therapeutic instrument for patients with FL, however timing within the treatment course has to be defined individually.

Current challenges in the management of follicular lymphoma

Although typically indolent in nature, follicular lymphoma remains an ongoing challenge for practicing oncologists. While response rates >90% can be achieved with rituximab-based chemoimmunotherapy in advanced stage patients, the complete remission rates are substantially lower and patients inevitably relapse. The inability to achieve a complete remission and an early progression of disease have recently been determined to be indicative of poorer long-term outcomes. A greater understanding of the pathogenesis of follicular lymphoma has enabled the development of targeted therapies, which may improve standard treatment approaches. Examples include lenalidomide and obinutuzumab, which are currently in front-line Phase III investigation. Other therapies of interest include small molecule inhibitors, immune checkpoint inhibitors and chimeric antigen receptor T cells.

Allogeneic Hematopoietic Cell Transplantation as Curative Therapy for Patients with Non-Hodgkin Lymphoma: Increasingly Successful Application to Older Patients

Non-Hodgkin lymphoma (NHL) constitutes a collection of lymphoproliferative disorders with widely varying biological, histological, and clinical features. For the B cell NHLs, great progress has been made due to the addition of monoclonal antibodies and, more recently, other novel agents including B cell receptor signaling inhibitors, immunomodulatory agents, and proteasome inhibitors. Autologous hematopoietic cell transplantation (auto-HCT) offers the promise of cure or prolonged remission in some NHL patients. For some patients, however, auto-HCT may never be a viable option, whereas in others, the disease may progress despite auto-HCT. In those settings, allogeneic HCT (allo-HCT) offers the potential for cure. Over the past 10 to 15 years, considerable progress has been made in the implementation of allo-HCT, such that this approach now is a highly effective therapy for patients up to (and even beyond) age 75 years. Recent advances in conventional lymphoma therapy, peritransplantation supportive care, patient selection, and donor selection (including the use of alternative hematopoietic cell donors), has allowed broader application of allo-HCT to patients with NHL. As a result, an ever-increasing number of NHL patients over age 60 to 65 years stand to benefit from allo-HCT. In this review, we present data in support of the use of allo-HCT for patients with diffuse large B cell lymphoma, follicular lymphoma, and mantle cell lymphoma. These histologies account for a large majority of allo-HCTs performed for patients over age 60 in the United States. Where possible, we highlight available data in older patients. This body of literature strongly supports the concept that allo-HCT should be offered to fit patients well beyond age 65 and, accordingly, that this treatment should be covered by their insurance carriers.