Castillo, Jorge J

ABSTRACT Disease Overview Plasmablastic lymphoma (PBL) is a rare CD20‐negative aggressive lymphoma with poor prognosis when treated with standard treatment options. Although PBL is associated with HIV infection and other immunosuppressed states, it can also affect immunocompetent individuals. Diagnosis The diagnosis of PBL requires a high clinical suspicion and pathological confirmation. EBV‐encoded RNA (EBER) expression and MYC gene rearrangements are frequently detected in the malignant cells. The differential diagnosis includes EBV+ diffuse large B‐cell lymphoma (DLBCL), extracavitary primary effusion lymphoma, ALK+ DLBCL, and HHV8+ large B‐cell lymphoma, among others. Risk Stratification Age ≥ 60 years, advanced clinical stage, and high International Prognostic Index scores are associated with worse survival. Management Combination chemotherapy regimens, such as infusional EPOCH, are recommended. The addition of bortezomib or daratumumab might improve outcomes. B‐cell maturation antigen‐targeted therapies have shown early efficacy. The participation of patients with PBL in prospective clinical trials is warranted.

Abstract Waldenström macroglobulinemia (WM) is characterized by recurrent MYD88 and CXCR4 mutations, whose prognostic value in patients treated with chemoimmunotherapy remains unclear. Moreover, the typically prolonged progression-free survival (PFS) correlates inconsistently with overall survival (OS), underscoring the importance of examining other surrogates. Progression of disease within 24 months (POD24), an established early end point, delineates functionally high-risk patients in other indolent lymphomas. This international study evaluated 253 patients receiving frontline fixed-duration bendamustine-rituximab (BR), a common chemoimmunotherapy for WM. At a median follow-up of 5.9 years, 5-year PFS and OS were 65% and 87%, respectively; 5-year PFS was similar between MYD88L265P (90%) and MYD88wild-type (WT) subcohorts (64% each; P = .4). Among 89 patients with known CXCR4 status, the subcohort with CXCR4mutation (28%) had shorter PFS (median 3.3 vs 8.8 years; hazard ratio [HR], 2.8; P = .0036) and OS (HR, 2.6; P = .036) compared with CXCR4WT. POD24 occurred in 11.5% of patients who demonstrated inferior subsequent OS (5-year OS, 71% vs 86%; HR, 3.1; P = .005) and higher mortality (standardized mortality ratio [SMR], 3.7), unlike the non-POD24 group, whose mortality was comparable to the matched general population (SMR, 1.1). In conclusion, BR is effective irrespective of the MYD88 status, but CXCR4 mutations and POD24 portend worse outcomes. Patients without POD24 represent a cohort with distinctly favorable outcome.

ABSTRACT As the treatment paradigm for Waldenström macroglobulinemia (WM) continues to evolve, the debate surrounding the prioritization of depth of response versus disease control as therapeutic goals gains significant relevance. However, the impact of depth of response from fixed‐duration therapy on overall survival (OS) was unclear. This multicenter study evaluated the prognostic impact of depth of response using a landmark survival analysis. A total of 440 patients with WM treated with frontline fixed‐duration regimens were included. Attaining a major response (MaR) was associated with superior outcomes, including significantly longer OS. The estimated 5‐year PFS rates for patients with MaR at 6 months versus not were 50% versus 32%, respectively, p < 0.001, and the estimated 5‐year OS rates for patients with MaR at 6 months versus not were 89% versus 70%, respectively, p < 0.001. In a multivariable analysis, MaR at 6 months was independently associated with superior PFS (HR 0.66, p = 0.007) and OS (HR 0.28, p < 0.001). Similar results were seen when considering deeper responses (CR + VGPR vs. PR). Depth of response at 6 months is an important prognostic marker in WM and an independent predictor of PFS and OS. These results support its utilization as a suitable endpoint in clinical studies in WM.

PURPOSE Patients with Waldenström macroglobulinemia (WM) have disparate outcomes. Newer therapies have emerged since the development of International Prognostic Scoring System, and MYD88 L265P mutation is now frequently assessed at diagnosis, warranting reexamination of the prognostic parameters. PATIENTS AND METHODS We reviewed records of 889 treatment-naïve patients with active WM, consecutively seen between January 01, 1996, and December 31, 2017, to identify clinical predictors of overall survival (OS) in univariate analyses. Patients with complete data for the parameters significant on the univariate analyses (n = 341) were included in a multivariable analysis to derive a prognostic model, subsequently validated in a multi-institutional cohort. RESULTS In the derivation cohort (n = 341), age (hazard ratio [HR], 1.9 [95% CI, 1.2 to 2.1]; P = .0009), serum lactate dehydrogenase (LDH) above upper limit of normal (HR, 2.3 [95% CI, 1.3 to 4.5]; P = .007), and serum albumin <3.5 g/dL (HR, 1.5 [95% CI, 0.99 to 2.3]; P = .056) were independently prognostic. By assigning a score of 1 point each to albumin <3.5 g/dL (HR, 1.5) and age 66-75 years (HR 1.4) and 2 points for age >75 years (HR, 2.6) or elevated LDH (HR, 2.3), four groups with distinct outcomes were observed on the basis of the composite scores. Five-year OS was 93% for the low-risk (score 0), 82% for low-intermediate risk (score 1), 69% for intermediate-risk (score 2), and 55% for the high-risk (score ≥3; P < .0001) groups. In the validation cohort (N = 335), the model maintained its prognostic value, with a 5-year OS of 93%, 90%, 75%, and 57% for the four groups, respectively ( P < .0001). CONCLUSION Modified Staging System for WM (MSS-WM), utilizing age, albumin, and LDH is a simple, clinically useful, and externally validated prognostic model that reliably risk-stratifies patients with symptomatic WM into four groups with distinct prognosis.

AbstractIbrutinib is a first-generation inhibitor of Bruton tyrosine kinase (BTK) that is currently approved to treat patients with B-cell malignancies, including Waldenström macroglobulinemia (WM), relapsed/refractory (R/R) mantle cell lymphoma (MCL), R/R marginal zone lymphoma (MZL), and chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). Off-target adverse effects, such as atrial fibrillation, hypertension, and bleeding, have been observed and may limit a patient’s tolerance for treatment. Currently, there is no well-established treatment regimen for patients who cannot tolerate ibrutinib. Approaches to address such patients include managing ibrutinib side effects with supportive care or dose reductions, switching to an alternative covalent BTK inhibitor, or abandoning covalent BTK inhibitors for alternative forms of treatment. Here we review the literature and provide guidance on treating ibrutinib-intolerant patients with B-cell malignancies.

AbstractPlasmablastic lymphoma (PBL) is a rare entity, commonly associated with immunosuppressed states such as human immunodeficiency virus (HIV) infection or solid organ transplant. The clinical course is characterized by high relapse rates and a poor prognosis, leading some clinicians to recommend aggressive frontline therapy. However, a specific review of limited stage (LS) PBL patients is not available to evaluate outcomes and justify treatment recommendations. We performed a retrospective review of LS PBL cases to provide insight into this rare disease. Our cohort consisted of 80 stage I or II PBL patients from 13 US academic centers. With a median follow up of 34 months (1–196), the 3‐year progression‐free survival (PFS) and overall survival (OS) of the entire cohort were 72% (95% CI 62, 83) and 79% (95% CI 70, 89), respectively. The 3‐year PFS and OS of patients treated with frontline chemotherapy alone was 65% (95% CI 50, 84) and 71% (95% CI 56, 89), respectively, compared to 85% (95% CI 72, 100) and 96% (95% CI 89, 100), respectively, in patients treated with combined frontline chemotherapy with radiation consolidation. Our data demonstrate favorable outcomes in LS PBL with no improvements in outcome from aggressive frontline treatment including Hyper‐CVAD or auto‐SCT consolidation. Multivariate regression analysis (MRA) demonstrated improved PFS for patients receiving EPOCH based frontline therapy versus CHOP (HR: 0.23; p = 0.029). Frontline chemotherapy followed by radiation consolidation versus chemotherapy alone appeared to be associated with improved relapse and survival outcomes but did not show statistical significance in MRA.

Waldenström macroglobulinemia (WM) is a rare form of non-Hodgkin B-cell lymphoma with a variable clinical presentation that can impact a patient’s quality of life by causing anemia, peripheral neuropathy, serum hyperviscosity, extramedullary disease, and other symptoms. There are several safe and effective treatment regimens for patients with WM, and the choice of therapy should be made in a personalized fashion considering the patient’s symptoms, comorbidities, and genomic profile. Bruton tyrosine kinase (BTK) inhibitors are a new option to treat patients with WM. Zanubrutinib is a next-generation covalent BTK inhibitor designed to have fewer off-target effects than previous BTK inhibitors. This review summarizes the pharmacokinetic and pharmacodynamic properties of zanubrutinib as well as safety and efficacy findings. Then, it explores the health economic and outcomes research associated with the costs of treating patients with WM and the reasons why zanubrutinib may be a more cost-effective treatment option compared with ibrutinib, a first-generation BTK inhibitor. Future directions for the treatment of WM focus on the use of zanubrutinib in combination therapy. Combinations based on effective ibrutinib or acalabrutinib treatments may be effectively applied with zanubrutinib given the similar mechanism of action for these BTK inhibitors. Combination therapies could also help prevent the development of disease resistance, minimize toxicity, and support treatment regimens of finite duration.