Autologous stem cell transplantation for follicular lymphoma is of most benefit early in the disease course and can result in durable remissions, irrespective of prior rituximab exposure

Personalised therapy in follicular lymphoma - is the dial turning?

Follicular lymphoma is the most common indolent lymphoma accounting for approximately 20%-25% of all new non-Hodgkin lymphoma diagnoses in western countries. Whilst outcomes are mostly favorable, the spectrum of clinical phenotypes includes high-risk groups with significantly inferior outcomes. This review discusses recent updates in risk stratification and treatment approaches from upfront treatment for limited and advanced stage follicular lymphoma to the growing options for relapsed, refractory disease with perspectives on how to approach this from a personalized lens. Notable gaps remain on how one can precisely and prospectively select optimal treatment for patients based on varying risks, with an anticipation that an increased understanding of the biology of these different phenotypes and increasing refinement of imaging- and biomarker-based tools will, in time, allow these gaps to be closed.

Long-term follow-up demonstrates curative potential of autologous stem cell transplantation for relapsed follicular lymphoma

Although autologous stem cell transplantation (ASCT) can achieve durable responses in eligible patients with follicular lymphoma (FL), long-term follow-up is needed to determine if it has curative potential. This retrospective, multicenter study included 162 patients who received ASCT for relapsed FL in Alberta, Canada. With a median (range) follow-up time of 12.5 years (0.1-27.9), the 12-year time-to-progression (TTP) was 57% (95% confidence interval [CI] 49%-65%), time-to-next-treatment was 61% (95% CI 52%-69%), progression-free survival was 51% (95% CI 42%-59%) and overall survival was 69% (95% CI 60%-76%). A plateau emerged on the TTP curve at 57% starting 9 years after ASCT with no relapses occurring beyond this timepoint. Ten patients remained in remission 20 years or more after ASCT. Patients undergoing ASCT at first or second relapse had superior outcomes compared to third or later relapse (12-year TTP 61% vs. 34%), as did patients without progression of disease within 24 months (POD24) of frontline treatment versus those with POD24 (12-year TTP 67% vs. 50%). ASCT achieves high rates of durable remission in relapsed FL, with long-term follow-up revealing that more than 50% of transplanted patients may be functionally cured of their lymphoma. The optimal timing to consider ASCT is at first or second relapse, regardless of POD24 status.

Treatment with Idelalisib in Patients with Relapsed or Refractory Follicular Lymphoma: The Observational Italian Multicenter FolIdela Study

Simple Summary

Idelalisib, the first-in-class phosphatidylinositol 3-kinase inhibitor, approved by the Italian Medicines Agency for the treatment of relapsed/refractory follicular lymphoma patients, showed high antitumor activity with an acceptable safety profile in a phase II registration trial. A 6-year follow-up of the same trial did not reveal any new safety concerns, confirming the role of idelalisib as an effective option for indolent non-Hodgkin lymphoma, refractory to previous therapies. The aim of this multicenter study is to point out the role of idelalisib in a real-life context, since data from everyday clinical practices are scarce. We report the effective and manageable safety profile of idelalisib in the treatment of 72 relapsed/refractory follicular lymphoma patients, bringing further demonstrations of its role in this setting.

Abstract

Follicular lymphoma (FL) is an indolent hematological disease, often responsive to the first line of treatment, but characterized by repeated relapses. The therapeutic algorithm for relapsed/refractory FL patients comprises phosphatidylinositol 3-kinase inhibitors. Idelalisib showed anticancer activity, while inducing a significant rate of toxicities. Since the evidence in the literature on its use in normal clinical practice is scarce, a retrospective multicenter study was conducted to evaluate effectiveness and tolerability in a real-life context. Seventy-two patients with a median age at diagnosis of 57.2 years—mostly with an advanced stage (88.9%) and relapsed to the most recent therapy (79.1%)—were enrolled. The median number of prior therapies was three (20.8% refractory to the last therapy before idelalisib). With a median number of 4 months of treatment, the overall response rate was 41.7% (20.8% complete responses). Median disease-free survival and overall survival were achieved at 8.4 months and at 4 years, respectively. Forty-four percent of patients experienced at least one drug-related toxicity: 6.9% hematological ones and 43% non-hematological. The study confirmed that idelalisib has anticancer effectiveness and an acceptable safety profile in relapsed/refractory FL with unfavorable prognostic characteristics, even in the context of normal clinical practice.

Novel Therapy Approaches to Follicular Lymphoma

Follicular lymphoma (FL) is the most common form of indolent non-Hodgkin lymphoma. It is a disease characterised by a long median overall survival and high response rates to currently available chemotherapy and anti-CD20 monoclonal antibody therapy combinations. However, for a sub-group of patients the disease behaves aggressively, fails to respond adequately to initial therapy or relapses early. For others, the disease becomes resistant following multiple lines of therapy, and despite recent advances the main cause of death for patients with FL remains their lymphoma. A wide landscape of novel therapies is emerging and the role of individual agents in the FL treatment paradigm is still being established. Some agents, including the cereblon modulator lenalidomide, the phosphatidylinositol 3-kinase inhibitors idelalisib, copanlisib and duvelisib, and the EZH2 inhibitor tazemetostat have received regulatory approval in the USA or European Union and have entered clinical practice for relapsed FL. Other developments, such as the emergence of immunotherapies including CAR-T cell therapy and bispecific antibodies, are expected to fundamentally change the approach to FL treatment in the future.

A multi-center retrospective analysis of patients with relapsed/refractory follicular lymphoma after third-line chemotherapy

The overall outcome of patients with advanced-stage follicular lymphoma (FL) has improved significantly. However, some patients still develop multiple relapsed/refractory FL (RRFL). To address the still-limited data on this population, we performed this multi-center retrospective study. We analyzed 41 patients who received third-line treatment for RRFL at 8 institutes. The median age at diagnosis was 59 years (range, 38-70). The median progression-free survival (PFS) and probability of PFS at 2 years were 1.61 years and 39.4%, respectively, after third-line chemotherapy, and 0.45 years and 19.0%, respectively, after fourth-line chemotherapy. Objective response (OR) after third-line chemotherapy was achieved in 24 patients (53.7%). Bendamustine (Ben)-based regimens were associated with a significantly higher OR rate than other regimens (77.8% vs. 40.0%, respectively, P = 0.025). The median overall survival (OS) and probability of OS at 2 years were 4.71 years and 65.9%, respectively, after third-line chemotherapy, and 1.01 year and 45.1%, respectively, after fourth-line chemotherapy. In conclusion, this study had a small sample size and retrospective design, but it was able to demonstrate poor response rate and duration in patients with multiple RRFL, particularly after fourth-line chemotherapy. The optimal treatment strategy in this population should be clarified, including possibly hematopoietic stem cell transplantation.

Early Progression of Follicular Lymphoma: Biology and Treatment

Follicular lymphoma is the most common subtype of indolent non-Hodgkin lymphoma. Although a majority of patients have a favorable prognosis, a subset of patients experiences early treatment failure. Progression of disease within 24 months of initial chemoimmunotherapy is associated with inferior survival. The biology of early progression is the subject of ongoing study and depends on the unique genetic composition of neoplastic cells and their interaction with a complex tumor microenvironment. Clinicogenetic prognostic indices have been developed to identify high-risk patients. Several have been validated but are limited in identifying those at risk for early treatment failure.

Clinical characteristics and outcomes of relapsed follicular lymphoma after autologous stem cell transplantation in the rituximab era

High-dose chemotherapy followed by autologous stem cell transplantation (ASCT) is a therapeutic option for patients with relapsed follicular lymphoma (FL). The clinical characteristics and outcomes of FL relapse after ASCT in the rituximab era have not yet been fully elucidated. We retrospectively reviewed 414 FL patients treated with ASCT between 2000 and 2014 in four hematology departments. All patients received rituximab as a first-line treatment. We specifically analyzed the clinical characteristics, treatment strategies at relapse, and outcomes of 95 patients (23%) who relapsed after ASCT. The patients (median age, 57 y) received a median of two lines of therapy (range, 2-6) prior to ASCT, with 92% in complete response (CR) or partial response (PR) before ASCT. Histological transformation at relapse after ASCT was observed in 20% of the patients. Treatment at relapse after ASCT consisted of chemotherapy with or without rituximab (n = 45/90, 50%), targeted agents (18%), rituximab monotherapy (14%), or consolidation allogeneic transplantation after induction chemotherapy (12%) and radiotherapy (6%). After relapse, the median progression-free survival (PFS) and overall survival (OS) were 1 year (95% CI, 0.541-1.579) and 5.5 years (95% CI, 1.910-9.099), respectively. In the multivariate analysis, histological transformation (HT) was associated with OS (P = .044; HR 2.439; 95% CI, 1.025-5.806), and a high FLIPI score at relapse was associated with PFS (P = .028; HR 2.469; 95% CI, 1.104-5.521). This retrospective study showed that the period of PFS of patients who relapsed after ASCT is short. A biopsy should be performed for these patients to document the HT. Our results indicate that new treatment strategies will need to be developed for these patients.

Non-Hodgkin lymphoma

Lymphomas can affect any organ in the body, present with a wide range of symptoms, and be seen by primary care physicians and physicians from most specialties. They are traditionally divided into Hodgkin's lymphoma (which accounts for about 10% of all lymphomas) and non-Hodgkin lymphoma, which is the topic of this Seminar. Non-Hodgkin lymphoma represents a wide spectrum of illnesses that vary from the most indolent to the most aggressive malignancies. They arise from lymphocytes that are at various stages of development, and the characteristics of the specific lymphoma subtype reflect those of the cell from which they originated. Since this topic was last reviewed in The Lancet in 2012, advances in understanding the biology and genetics of non-Hodgkin lymphoma and the availability of new diagnostic methods and therapies have improved our ability to manage patients with this disorder.

Autologous Stem Cell Transplantation for Follicular Lymphoma: Favorable Long-Term Survival Irrespective of Pretransplantation Rituximab Exposure

High-dose chemotherapy supported by autologous stem cell transplantation (HDT/ASCT) has contributed to modify the natural history of follicular lymphoma (FL); however, an overall survival (OS) benefit has been demonstrated at relapse only after a rituximab-free chemotherapy regimen. A total of 655 patients with FL were reported to the Spanish GELTAMO (Grupo Español de Linfomas y Trasplantes de Médula Ósea) registry and underwent first ASCT between 1989 and 2007. A total of 203 patients underwent ASCT in first complete response (CR1), 174 in second complete response (CR2), 28 in third complete response (CR3), 140 in first partial response (PR1), 81 in subsequent PR, and 29 with resistant/refractory disease; 184 patients received rituximab before ASCT. With a median follow-up of 12 years from ASCT, median progression-free survival (PFS) and overall survival (OS) were 9.7 and 21.3 years, respectively. Actuarial 12-year PFS and OS were 63% (95% confidence interval [CI], 58%-68%) and 73% (95% CI, 68%-78%), respectively, for patients in CR (with a plateau in the curve beyond 15.9 years), 25% (95% CI, 19%-28%) and 49% (95% CI 42%-56%), respectively, for patients in PR, and 23% (95% CI, 8%-48%) and 28% (95% CI, 9%-45%), respectively, for patients with resistant/refractory disease (P < .001). In patients who received rituximab before ASCT, the estimated 9-year PFS and OS from ASCT were 59.5% (95% CI, 51%-67%) and 75% (95% CI, 68%-83%), respectively. Interestingly, for patients who underwent transplantation in CR ≥2 or PR ≥2 who had received rituximab before ASCT (n = 90), 9-year PFS and OS were 61% (95% CI, 51%-73%) and 75% (95% CI, 65%-80%), respectively, with no relapses occurring beyond 5.1 years after ASCT. The cumulative incidence of second malignancies in the global series was 6.7% at 5 years and 12.8% at 10 years. This analysis strongly suggests that ASCT is a potentially curative option for eligible patients with FL. In the setting of relapse, it is of especial interest in pretransplantation rituximab-sensitive patients with FL.

Reappraising the timing of transplant for indolent non-Hodgkin lymphomas

INTRODUCTION

Indolent non-Hodgkin lymphomas (iNHL) remain incurable with standard approaches. The timing of autologous stem cell transplant (ASCT) is changing following the introduction of new drugs that can potentially defer the transplant, improved reduced intensity conditioning (RIC) and haploidentical allogeneic SCT (allo-SCT).

AREAS COVERED

The most relevant aspects concerning the role of hematopoietic stem cell transplantation in the management of iNHL are discussed. Literature search methodology included examination of PubMed index and meeting presentations. Expert commentary: ASCT is not currently employed as consolidation in first-line, being reserved to patients with refractory/relapsed disease. The curative potential of graft-versus-lymphoma (GVL) after RIC allo-SCT could be particularly beneficial in patients with iNHL relapsing after ASCT. This scenario could be modified in the near future by better definition of high-risk patients at diagnosis, by the improvement of minimal residual disease (MRD) evaluation and by the introduction of new drugs in the therapeutic algorithm.

Reduced-Intensity Conditioning with Fludarabine, Cyclophosphamide, and High-Dose Rituximab for Allogeneic Hematopoietic Cell Transplantation for Follicular Lymphoma: A Phase Two Multicenter Trial from the Blood and Marrow Transplant Clinical Trials Network

Allogeneic (allo) hematopoietic cell transplantation (HCT) can induce long-term remissions in chemosensitive relapsed follicular lymphoma (FL). The Blood and Marrow Transplant Clinical Trials Network conducted a multicenter phase 2 trial to examine the efficacy of alloHCT using reduced-intensity conditioning with rituximab (RTX) in multiply relapsed, chemosensitive FL. The primary endpoint was 2-year progression-free survival (PFS). The conditioning regimen consisted of fludarabine, cyclophosphamide, and high-dose RTX (FCR), in which 3 of the 4 doses of RTX were administered at a dose of 1 gm/m(2). Graft-versus-host disease (GVHD) prophylaxis was with tacrolimus and methotrexate. Sixty-five patients were enrolled and 62 were evaluable. Median age was 55 years (range, 29 to 74). This group was heavily pretreated: 77% had received ≥ 3 prior regimens, 32% had received ≥ 5 prior regimens, and 11% had received prior autologous HCT. Donors were HLA-matched siblings (n = 33) or HLA-matched unrelated adults (n = 29). No graft failures occurred. The overall response rate after HCT was 94% with 90% in complete remission (CR), including 24 patients not in CR before alloHCT. With a median follow-up of 47 months (range, 30 to 73), 3-year PFS and overall survival rates were 71% (95% confidence interval, 58% to 81%) and 82% (95% confidence interval, 70% to 90%), respectively. Three-year cumulative incidences of relapse/progression and nonrelapse mortality were 13% and 16%, respectively. Two-year cumulative incidences of grades 2 to 4 and grades 3 or 4 acute GVHD were 27% and 10%, respectively, and extensive chronic GVHD incidence was 55%. Serum RTX concentrations peaked at day +28 and remained detectable as late as 1 year in 59% of patients with available data. In conclusion, alloHCT with FCR conditioning confers high CR rates, a low incidence of relapse/progression, and excellent survival probabilities in heavily pretreated FL patients.

Autologous stem cell transplantation with in vivo purged progenitor cells shows long-term efficacy in relapsed/refractory follicular lymphoma

High-dose chemotherapy with autologous stem cell transplantation (ASCT) has been shown effective in the control of relapsed/refractory follicular lymphoma. We evaluate the long-term outcome of patients with relapsed or refractory follicular lymphoma treated with ASCT with in vivo purged progenitors cells. We report the long-term results of a prospective multicenter phase 2 trial on 124 relapsed/refractory follicular lymphoma patients treated with a program of anthracycline-based debulking chemotherapy, immunochemotherapy, mobilization of in vivo purged PBSC followed by ASCT. Median age was 52 years; 14% of patients had grade 3A histology. Debulking chemotherapy produced CR in 16% and PR in 71%, while 13% of patients progressed. After rituximab, cyclophosphamide, vincristine, prednisone (R-COP), CR was obtained in 60% and PR in 35%; 118 patients successfully mobilized PBSC and 117 proceeded to ASCT. The harvest in all the 32 molecularly informative patients was bcl-2 negative. TRM was 0%. The 5-year PFS was 54% and the 5-year OS was 83%. After a median f-up of 6.7 years (range 1.5-13.6), 54% are still in CR. These data show that prolonged PFS is achievable in relapsed/refractory patients with high dose autologous transplantation of in vivo purged progenitor cells.

PET/CT before autologous stem cell transplantation predicts outcome in refractory/relapsed follicular lymphoma

PURPOSE

Salvage of young patients with follicular lymphoma (FL) after R-CHOP includes salvage immunochemotherapy followed by autologous stem cell transplantation (ASCT). Previous studies dealing with relapsed Hodgkin lymphoma have shown the prognostic value of PET/CT prior to ASCT.

METHODS

We retrospectively analysed 59 patients with refractory/relapsed FL after first-line R-CHOP who were chemosensitive (as evaluated by CT) to the salvage treatment and who proceeded to ASCT. The role of PET/CT in this setting to define chemosensitivity is not definitely established. So we focused on the prognostic value of PET/CT performed after salvage treatment, before ASCT.

RESULTS

The estimated 3-year progression-free survival (PFS) and overall survival were 63.1% (50.9-78.3%) and 90.5% (82.8 - 98.8%), respectively, and did not differ significantly according to their Follicular Lymphoma International Prognostic Index at relapse, conditioning regimen, or type of salvage. PFS was significantly lower in PET/CT-positive patients, according to the International Harmonization Project revised response criteria, with a 3-year PFS of 45.5% (26.6 - 77.8%) versus 72.6% (58.5 - 90.0%; p = 0.039). To better refine prognosis, we applied two types of throsholds: a Deauville five-point scale positive threshold of ≥3 (3-year PFS of 74.9%, range 61.0 - 92.1% %, versus 42.8%, range 24.7 - 74.4%; p = 0.02), and a ≥70% ∆SUVmax threshold between presalvage and pre-ASCT PET/CT (3-year PFS of 72.4%, range 57.5 - 91.3% versus 13.3%, 2.2 - 81.7%; p < 10(-3)). The PET/CT findings before ASCT were independently correlated with PFS in our series.

CONCLUSION

PET/CT negativity before ASCT is a desirable and achievable goal in the management of chemosensitive FL relapsing after first-line R-CHOP.

Phase II study of first-line (131)I-rituximab radioimmunotherapy in follicular non-Hodgkin lymphoma and prognostic (18)F-fluorodeoxyglucose positron emission tomography

First-line (131)I-anti-CD20 radioimmunotherapy of indolent non-Hodgkin lymphoma (NHL) achieves durable remission with low toxicity. The phase II INITIAL study comprised 68 patients with follicular NHL followed up to 7 years (median 4 years) after outpatient (131)I-rituximab radioimmunotherapy (RIT) in conjunction with rituximab, followed by maintenance therapy for 1 year. Baseline and 3-month (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) imaging, analyzed according to Deauville criteria, was used to evaluate response and predict prognosis. The overall response rate at 3 months was 99%, with 88% achieving Deauville category 1-3. These satisfactory responders did not reach median time-to-next-treatment, versus a median of 29 months for a category 4-5 response (p < 0.0001). Grade IV hematological toxicity (9%) was self-limited without clinical sequelae. (131)I-rituximab radioimmunotherapy in newly diagnosed, advanced stage, symptomatic follicular NHL is an effective, practical and affordable alternative to existing conventional chemotherapies, with lower toxicity and durable remissions. Response assessment at 3 months by (18)F-FDG PET Deauville five-point scale permits prognostic stratification.