Long-term follow-up of lenalidomide and rituximab as initial treatment of follicular lymphoma

Progression-free survival after front line, second line and third line in patients with follicular lymphoma treated in clinical practice

BACKGROUND

The modern-day therapeutic landscape for follicular lymphoma (FL) includes a number of highly effective therapies.

PATIENTS AND METHODS

We set out to determine progression-free survival (PFS) after front line, second line, and third line of therapy on the basis of relevant biological characteristics and therapeutic choices. Patients (n = 743, 51% females, median 60 years old) diagnosed with grade 1-2 FL between 1997 and 2016 in nine institutions were included.

RESULTS

The median PFS1, PFS2, and PFS3 were 8.1 years (95% confidence interval [CI]: 7-9.3 years), 4.2 years (95% CI: 2.8-5.6 years) and 2.2 years (95% CI 1.7-2.8 years). We found longer PFS1 for (1) females, (2) younger age, (3) lower-risk follicular lymphoma international prognostic index (FLIPI), (4) standard intensity (over low intensity) regimens and (5) immunochemotherapy strategies and (6) maintenance rituximab. We found a shorter PFS2 for patients who received front-line immunochemotherapy. Older age at diagnosis correlated with a shorter PFS3. Intensity of front-line chemotherapy, maintenance, or POD24 status did not correlate with PFS2 or PFS3 in this dataset.

INTERPRETATION

With current immunochemotherapy strategies, the natural course of FL is characterized by shorter-lasting remissions after each relapse. It will be interesting to see whether new therapies can alter this pattern.

Analyzing the risk factors for disease progression within 2 years and histological transformation in patients treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone as first-line treatment: A 15-year follow-up of patients with advanced follicular lymphoma in JCOG0203

Follicular lymphoma (FL) is an indolent lymphoma that becomes aggressive due to histological transformation (HT), leading to reduced survival. Patients with FL have different clinical courses and various treatment options. Some patients exhibit shorter survival and experience disease progression within 24 months of diagnosis/treatment (POD24); the optimal treatment remains an unmet needs. Thus, identifying factors that predict shorter survival is essential to stratify treatment and prolong the survival of patients with FL. To analyze risk factors for POD24 and HT in patients treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) as first-line treatment, we performed this post-hoc analysis of patients with advanced indolent B-cell lymphoma in a randomized clinical trial wherein six cycles of R-CHOP were administered every 2-3 weeks. The primary analysis showed no differences in outcomes, which enabled the analysis of 248 patients with FL, assigned to two arms. All histopathological specimens from the 300 enrolled patients were reviewed by three expert hematopathologists. Multivariable analysis implicated Follicular Lymphoma International Prognostic Index (FLIPI) intermediate (odds ratio [OR] 2.531, 95% confidence interval [CI] 0.676-9.466) and high- (OR 2.236, 95% CI 0.160-31.226) risks, B symptoms (OR 2.091, 95% CI 0.747-5.851), and grade 3A (G3A) (OR 1.833, 95% CI 0.634-5.299) as risk factors for POD24. Furthermore, multivariable analysis through a median follow-up of 15.9 years implicated G3A (OR 2.628, 95% CI 0.806-8.575) and high-risk FLIPI (OR 4.401, 95% CI 0.186-104.377) as risk factors for HT. However, an analysis limited to the first 10 years revealed that the prognostic factors elucidated from the longer-term analysis had a greater impact on HT. G3A and high-risk FLIPI may independently predict POD24 and HT, thereby informing treatment stratification of patients with untreated advanced-stage FL in future trials, particularly to address the unmet needs of patients with POD24.

Radioimmunotherapy versus autologous hematopoietic stem cell transplantation in relapsed/refractory follicular lymphoma: a Fondazione Italiana Linfomi multicenter, randomized, phase III trial

BACKGROUND

Optimal consolidation for young patilents with relapsed/refractory (R/R) follicular lymphoma (FL) remains uncertain in the rituximab era, with an unclear benefit of autologous stem cell transplantation (ASCT). The multicenter, randomized, phase III FLAZ12 (NCT01827605) trial compared anti-CD20 radioimmunotherapy (RIT) with ASCT as consolidation after chemoimmunotherapy, both followed by rituximab maintenance.

PATIENTS AND METHODS

Patients (age 18-65 years) with R/R FL and without significant comorbidities were enrolled and treated with three courses of conventional, investigator-chosen chemoimmunotherapies. Those experiencing at least a partial response were randomized 1 : 1 to ASCT or RIT before CD34+ collection, and all received postconsolidation rituximab maintenance. Progression-free survival (PFS) was the primary endpoint. The target sample size was 210 (105/group).

RESULTS

Between August 2012 and September 2019, of 164 screened patients, 159 were enrolled [median age 57 (interquartile range 49-62) years, 55% male, 57% stage IV, 20% bulky disease]. The study was closed prematurely because of low accrual. Data were analyzed on 8 June 2023, on an intention-to-treat basis, with a 77-month median follow-up from enrollment. Of the 141 patients (89%), 70 were randomized to ASCT and 71 to RIT. The estimated 3-year PFS in both groups was 62% (hazard ratio 1.11, 95% confidence interval 0.69-1.80, P = 0.6662). The 3-year overall survival also was similar between the two groups. Rates of grade ≥3 hematological toxicity were 94% with ASCT versus 46% with RIT (P < 0.001), and grade ≥3 neutropenia occurred in 94% versus 41%, respectively (P < 0.001). Second cancers occurred in nine patients after ASCT and three after radioimmunotherapy (P = 0.189).

CONCLUSIONS

Even if prematurely discontinued, our study did not demonstrate the superiority of ASCT versus RIT. ASCT was more toxic and demanding for patients and health services. Both strategies yielded similar, favorable long-term outcomes, suggesting that consolidation programs milder than ASCT require further investigation in R/R FL.

SIRPα+ macrophages are increased in patients with FL who progress or relapse after frontline lenalidomide and rituximab

Chemoimmunotherapy is an effective treatment strategy for patients with FL who relapse after frontline R².

SIRPα⁺ and CSF1R⁺macrophages are increased in FL patients who relapse after frontline R².

Limited data exist regarding the outcome of patients with follicular lymphoma (FL) who relapse or progress after frontline lenalidomide and rituximab (R²). Moreover, mechanisms of resistance to R² in FL remain unclear, with increased protumoral macrophages suspected as a major contributory culprit to this phenomenon. This retrospective study analyzed the outcome of patients with advanced-stage FL grade 1 to 3A who relapsed or progressed after frontline R². A multiplex immunofluorescence macrophage panel, including CD47, CD14, CD68, CD115 (also known as colony-stimulating factor 1 receptor [CSF1R]), CD163, CD172a (also known as signal regulatory protein α [SIRPα]), and CD274 (also known as programmed cell death-ligand 1 [PDL1]), was used to stain tissue biopsy specimens collected before initiation of R² and at the time of progression. Among 156 patients with advanced-stage FL treated with frontline R², 33 (21%) relapsed or progressed and required second-line therapy, after a median of 33 months (range, 1-122 months). Second-line therapy was chemoimmunotherapy in 16 (48%) patients and other therapy in 17 (52%). The overall response rate was 78%, and complete response rate was 72%. Median progression-free survival was significantly longer in patients who received chemoimmunotherapy compared with other therapy (99 vs 25 months; P = .004). Three macrophage populations were significantly increased in tissue samples collected at progression compared with before frontline treatment: CD68⁺CD115⁺ (P = .02), CD68⁺CD115⁺CD172a⁺ (P = .02), and CD68⁺CD163⁺CD172a⁺ (P = .01). Chemoimmunotherapy is an effective treatment strategy for patients with FL who relapse after frontline R². Therapies targeting specific macrophage populations may yield novel approaches for improving outcomes with frontline R².

Follicular lymphoma and macrophages: impact of approved and novel therapies

The survival and proliferation of follicular lymphoma (FL) cells are strongly dependent on macrophages, because their presence is necessary for the propagation of FL cells in vitro. To this regard, as also shown for the majority of solid tumors, a high tissue content of tumor-associated macrophages (TAMs), particularly if showing a protumoral phenotype (also called M2), is strongly associated with a poor outcome among patients with FL treated with chemotherapy. The introduction of rituximab, an anti-CD20 antibody that can be used by TAMs to facilitate antibody-dependent cellular cytotoxicity and antibody-dependent cellular phagocytosis, has challenged this paradigm. In the rituximab era, clinical studies have yielded conflicting results in FL, showing variable outcomes based on the type of regimen used. This highlighted, for the first time, that the impact of TAMs on the prognosis of patients with FL may depend on the administered treatment, emphasizing the need to better understand how currently available therapies affect macrophage function in FL. We summarize the impact of approved and novel therapies for FL, including radiation therapy, chemotherapy, anti-CD20 monoclonal antibodies, lenalidomide, and targeted agents, on the biology of TAMs and describe their effects on macrophage phagocytosis, polarization, and function. Although novel agents targeting the CD47/SIRPα axis are being developed and show promising activity in FL, a deeper understanding of macrophage biology and their complex pathways will help to develop novel and safer therapeutic strategies for patients with this type of lymphoma.

Role of lenalidomide in the treatment of peripheral T-cell non-Hodgkin lymphomas

T-cell lymphomas (TCLs) represent a group of lymphoid neoplasms characterized by an aggressive clinical course, even after an anthracycline-containing regimen. Novel agents for patients with relapsed/refractory TCL are urgently needed. Lenalidomide is an oral drug with immunomodulatory, antiangiogenic and direct antineoplastic effects. These peculiar mechanisms of action make TCL an attractive target for lenalidomide. We have identified five clinical trials in which lenalidomide monotherapy was investigated to treat TCL, including cutaneous TCL (CTCL) and adult T-cell lymphoma/leukemia (ATLL). In the ATLL-002 study, the overall response rate (ORR) was 42% and median progression-free survival (PFS) and overall survival were 3.8 mo and 20.3 mo, respectively. In a phase II trial for CTCL, ORR was 28% and median PFS and overall survival were 8 mo and 43 mo, respectively. For nodal peripheral TCL, ORR was between 10% and 43% in three clinical trials, with a median PFS of about 4 mo, even if some patients had a durable response. Overall toxicity is manageable and grade 3-4 events are mainly hematological and reversible. Combination strategies did not improve PFS. In conclusion, lenalidomide could represent a suitable treatment option for relapsed/refractory TCL, especially for neoplasms with a T-follicular helper origin, such as angioimmunoblastic TCL.

An Overview of Lenalidomide in Combination with Rituximab for the Treatment of Adult Patients with Follicular Lymphoma: The Evidence to Date

Follicular lymphoma (FL) is an indolent (low-grade) malignancy of B cells and is among the most common hematological cancers affecting adults. Its clinical presentation, natural course, and severity are highly variable. Management of FL depends on the clinical setting; most patients require multiple lines of treatment. Chemoimmunotherapy is the standard of care for FL patients needing treatment; however, alternative treatments are limited for refractory patients or those unfit for chemoimmunotherapy. Multiple alternatives to chemoimmunotherapy for FL are being developed, with some showing significant promise. Lenalidomide combination with rituximab (LR) is among the most successful and extensively studied novel approaches. LR has been compared head-to-head in clinical trials with rituximab monotherapy and chemoimmunotherapy in the frontline and to lenalidomide or rituximab monotherapy in the relapsed or refractory setting for the treatment of FL. Initial reports of these nine trials have been published in the last decade, and their long-term data will be available in the coming years. LR offered superior efficacy to either lenalidomide or rituximab monotherapy alone. The RELEVANCE trial compared the efficacy of LR with chemoimmunotherapy among 1030 FL patients and demonstrated similar efficacy with a different side effect profile. Myelosuppression, rash, and fatigue were among the significant adverse events. Most patients treated with LR received thromboprophylaxis. This paper aims to summarize and comment on the published evidence regarding LR treatment for FL through a literature review. The clinical trials will be presented in detail, and methodological differences complicating their comparisons will be discussed.