Italian real life experience with ibrutinib: results of a large observational study on 77 relapsed/refractory mantle cell lymphoma

Real-World Evidence of Relapsed/Refractory Mantle Cell Lymphoma Patients and Treatments: A Systematic Review

Introduction

Mantle cell lymphoma (MCL) is an incurable disease with an aggressive clinical course, and most patients eventually relapse after chemotherapy. Targeted therapies developed for relapsed/refractory MCL have been approved based on clinical trial data. However, real-world setting data are scarce and scattered.

Areas Covered

This systematic review aimed to collect, synthesize, and describe the characteristics and treatment outcomes of patients with relapsed/refractory MCL after receiving a second or subsequent line of therapy in the real-world setting.

Expert Opinion

R/R MCL is clinically and biologically heterogeneous and still represents a therapeutic challenge, with high-risk and early relapsed patients remaining an unmet medical need. This systematic review is limited by the quality of the available data and the difficulty of comparing outcomes in R/R MCL due to the heterogeneity of the disease, but the results suggest that covalent BTKis should be positioned as second-line therapy, followed by CAR T-cells in BTK-i-relapsed patients. Chemo-free and combination therapies with established chemoimmunotherapy backbones in the relapsed and front-line settings have been recently developed, and front-line options are being improved to move targeted and cellular therapies to earlier lines, including front-line therapy, in elderly and younger fit patients. In the upcoming years, many new targeted agents will play an important role and will be incorporated to the routine practice as their sequence, and outcomes in unselected patients are determined.

FIRE Study: Real-World Effectiveness and Safety of Ibrutinib in Clinical Practice in Patients with CLL and MCL

The FIRE study investigated the real-world effectiveness and safety of ibrutinib in prospectively observed patients with chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL) and mantle cell lymphoma (MCL) in France. Patients were mostly relapsed/refractory with high-risk features. First-line CLL/SLL patients had del17p and/or TP53 mutations. In this interim analysis, the median follow-up time for patients with CLL/SLL and MCL was 17.7 and 15.1 months, respectively. In the effectiveness populations for CLL/SLL (n = 200) and MCL (n = 59), the median progression-free survival was not estimable and 12.4 months, respectively; the 12-month overall survival rates were 88.5% and 65.8%, respectively. Treatment-emergent adverse events of interest for patients with CLL/SLL (n = 202) and MCL (n = 59) included: infections and infestations (53.5% and 32.2%), major bleeding (5.0% and 5.1%), and atrial fibrillation (5.9% and 8.5%); 135 (66.8%) and 20 (33.9%) patients were continuing treatment at the time of data cutoff. Future analyses will report on longer-term follow-up (Trial registration: ClinicalTrials.gov, NCT03425591. Registered 1 February 2018—Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03425591).

The Safety of Bruton's Tyrosine Kinase Inhibitors in B-cell Malignancies: A Systematic Review

B-cell malignancies, most notably lymphomas, make up most of the non-Hodgkin lymphomas in the United States. There is limited randomized data comparing 1^st and 2^nd generation Bruton Tyrosine Kinase inhibitors. Our aim was to compare the safety profiles of 1^st versus 2^nd generation Bruton Tyrosine Kinase inhibitors. A systematic search was performed from database inception to January 13, 2020. Studies with Bruton Tyrosine Kinase inhibitor monotherapy for the treatment of B-cell malignancies in the adult population (> 18 years old) were utilized and the adverse events were extracted. Fifty-five studies that met the inclusion criteria were included in the systematic review with forty-one studies with 1^st generation and fourteen studies with 2^nd generation. The review included both clinical trials and retrospective studies with average time of follow-up of 2 years for the 1^st generation group and 18 months for the 2^nd generation group. We found that the incidence of cardiovascular adverse events was significantly higher in the 1^st generation group (20.8%) as compared to the 2^nd generation group (6.3%). However, there was a higher incidence of hematologic/oncologic and gastrointestinal side effects in the 2^nd generation group compared to the 1^st (62.3% compared to 39.2% and 36.9% compare to 28.9%). The number of Grade 5 cardiovascular events (death) were same in the 1^st generation group compared to the 2^nd generation. Further research is needed to develop highly selective Bruton Tyrosine Kinase inhibitors to avoid unwanted adverse events by minimizing off-targets. This article is protected by copyright. All rights reserved.

IBRORS-MCL study: a Spanish retrospective and observational study of relapsed/refractory mantle-cell lymphoma treated with ibrutinib in routine clinical practice

This retrospective study evaluated 66 patients diagnosed with relapsed and/or refractory mantle cell lymphoma (R/R MCL) treated with ibrutinib in Spain in routine clinical practice. At diagnosis, patients had a median age of 64.5 years, 63.6% presented with intermediate/high sMIPI (simplified prognostic index for advanced-stage mantle cell lymphoma), 24.5% had the blastoid variant, and 55.6% had a Ki67 > 30%. Patients had received a median of 2 prior lines of therapy (range 1-2; min-max 1-7). Overall response rate was 63.5%, with 38.1% of patients achieving complete response (CR). With a median duration of ibrutinib exposure of 10.7 months (range 5.2-19.6; min-max 0.3-36), the median progression-free survival (PFS) and overall survival (OS) were 20 months [95% confidence interval (CI) 8.8-31.1] and 32 months (95% CI 22.6-41.3), respectively, and were not reached in patients achieving CR. No grade ≥ 3 cardiovascular toxicity or bleeding was reported. This study supports that treatment with ibrutinib leads to high response rates and favorable survival outcomes in patients with R/R MCL.

Ibrutinib as monotherapy versus combination therapy in Chinese patients with relapsed/refractory mantle cell lymphoma: A multicenter study

BACKGROUND

Ibrutinib has revolutionized the treatment of mantle cell lymphoma (MCL). Both ibrutinib monotherapy and ibrutinib-based combination therapy are important salvage options for patients with relapsed/refractory (R/R) MCL. The real-world efficacy and safety profile of the two strategies in Chinese patients with R/R MCL remain unclarified.

METHODS

In the present study, data of 121 R/R MCL patients who received either ibrutinib monotherapy (N = 68) or ibrutinib combination therapy (N = 53) in 13 medical centers in China were retrospectively reviewed.

RESULTS

With a median follow-up of 20.5 months, the overall response rate was 60.3% versus 84.9% (p = 0.003), complete remission rate was 16.2% versus 43.4% (p < 0.001), and median progression-free survival (PFS) was 18.5 months (95% confidence interval [CI], 12.1-21.8) vs. 30.8 months (95% CI, 23.5-NR) (hazard ratio, 0.53 [95% CI, 0.30-0.93]; p = 0.025), with ibrutinib monotherapy and ibrutinib-based combination therapy, respectively. Subgroup analysis showed that patients with male gender, no refractory disease, Ki67 <30%, previous line of therapy = 1, non-blastoid subtype, and the number of extranodal sites involved <2 might benefits more from the combination therapy. Treatment-emergent adverse events were similar, except for a higher incidence of all grade neutropenia in the ibrutinib combination group (12.7% vs. 32.0%, p = 0.017).

CONCLUSIONS

Ibrutinib combination therapy demonstrated potentially superior efficacy and comparable tolerability to ibrutinib monotherapy. Ibrutinib-based combination therapy could be one of the prominent treatment options for R/R MCL patients.

Ibrutinib in patients with relapsed/refractory mantle cell lymphoma: a real-life, retrospective, multicenter trial on behalf of the "RTL" (regional Tuscan lymphoma network)

BACKGROUND

Relapsed or refractory (R/R) mantle-cell lymphoma (MCL) patients have a poor prognosis and their management is challenging, in absence of a golden standard as salvage treatment. Bruton's tyrosine kinase inhibitor ibrutinib represents an effective treatment for R/R MCL patients. We investigated ibrutinib efficacy and safety in daily clinical practice, together with factors that could predict disease outcome.

PATIENTS AND METHODS

We retrospectively analyzed 69 consecutive R/R MCL patients managed in 10 Tuscan onco-hematological centers. The treatment regimen consisted of oral, continuous, single-agent ibrutinib, maximum dosage of 560 mg once per day, until disease progression.

RESULTS

Overall response rate was 62.3%, with a CR rate of 39.1%. After a median follow-up of 15.6 months, 40/69 patients (58%) were alive, the main cause of death was progressive disease (PD, 22/69 cases, 31.9%). Median progression-free survival (PFS) and overall survival (OS) were 17 and 34.8 months. Inferior PFS was associated with >1 prior line of therapy and B symptoms. Ibrutinib refractoriness was associated with inferior OS, median OS after ibrutinib failure was only 5 months.

DISCUSSION AND CONCLUSION

In this real-life setting ibrutinib treatment prolonged survival in R/R MCL patients, without unexpected adverse events. Patients receiving ibrutinib as 2^nd line regimen had the most favorable outcome.

Treatment patterns and outcomes among mantle cell lymphoma patients treated with ibrutinib in the United States: a retrospective electronic medical record database and chart review study

The experience of patients with mantle cell lymphoma (MCL) in community oncology practices, including reasons for treatment discontinuation, is sparse. This retrospective study sought to elucidate treatment patterns and outcomes of patients with MCL treated with ibrutinib in the community setting. Patients were identified from the US Oncology Network electronic medical records database, iKnowMed^TM , between 1 November 2013 and 31 October 2016. Descriptive analysis was performed to describe the demographic and clinical characteristics of the population. Kaplan-Meier estimates were performed to determine clinical outcomes. A Cox proportional hazards model was used to identify predictors of survival. Of the 1914 patients identified with MCL, 159 were treated with ibrutinib. The median age was 71 years and the majority were male (76%) and Caucasian (89%). The overall discontinuation rate was 83·6%; the most common reasons were progression (35%) and toxicities (25·6%). The median overall survival and progression-free survival was 25·82 months (95% confidence interval [CI] 19·94, NR) and 19·55 months (95% CI 16·52, 24·28) respectively. In multivariate modelling, patient age was predictive of survival (hazard ratio 1·041, P = 0·0186). Ibrutinib was temporarily reduced in 16·4% (n = 26) and held in 30·2% (n = 48), primarily due to toxicity 66·7% (n = 32). Survival data showed similarities between community oncology practices and clinical trials.

Clinical outcomes for ibrutinib in relapsed or refractory mantle cell lymphoma in real-world experience

Ibrutinib is highly effective in patients with relapsed or refractory mantle cell lymphoma (MCL) in major clinical trials. Although there has been a dramatic improvement in survival outcomes in the salvage setting, nonresponders to ibrutinib have a bleak prognosis. Therefore, this retrospective study was conducted to identify the most appropriate therapeutic strategy and prognosis‐related factors to predict the response of patients with relapsed or refractory MCL to ibrutinib monotherapy. Thirty‐three consecutive refractory or relapsed MCL patients treated with ibrutinib were analyzed in this study. The median overall survival (OS) and progression‐free survival (PFS) after initiation of ibrutinib were 35.1 months and 27.4 months, respectively. Risk factor analysis showed that high risk according to the Mantle Cell Lymphoma International Prognostic Index (MIPI) and nonresponse to ibrutinib at the first three cycles were significantly associated with inferior OS. Poor PFS was associated with high‐risk biologic MIPI, prior bendamustine exposure, and nonresponse to ibrutinib during the first three cycles. After ibrutinib failure, primary nonresponders had poorer OS and PFS than inconsistent responders. The overall response rate for the first salvage therapy was only 33%, with a median TTP of 3.2 months. There was no effective therapeutic strategy except for allogeneic hematopoietic stem cell transplantation (allo‐HSCT). Although ibrutinib responders exhibited favorable survival outcomes, nonresponders had a dismal prognosis. To overcome these limitations, it may be necessary to modify therapeutic strategies, such as selecting inconsistent responders for earlier allo‐HSCT.

Acalabrutinib for mantle cell lymphoma

Mantle cell lymphoma (MCL) is a unique type of non-Hodgkin lymphoma characterized by the overexpression of cyclin D1. MCL patients typically live for years but experience multiple relapses. Acalabrutinib is a novel second-generation oral Bruton tyrosine kinase inhibitor approved by the US Food and Drug Administration for relapsed MCL based on a clinical trial demonstrating an overall response rate of 81%. It provides a valuable new treatment option for MCL patients and is now being tested upfront.