Ibrutinib and venetoclax as primary therapy in symptomatic, treatment-naïve Waldenström macroglobulinemia.

ABSTRACT: Concurrent Bruton tyrosine kinase and BCL2 inhibition has not yet been investigated in Waldenström macroglobulinemia (WM). We performed an investigator-initiated trial of ibrutinib and venetoclax in symptomatic treatment-naïve patients with MYD88-mutated WM. Patients received ibrutinib 420 mg once daily (cycle 1), followed by a ramp-up of venetoclax to 400 mg daily (cycle 2). The combination was then administered for 22 additional 4-week cycles. The attainment of very good partial response (VGPR) was the primary end point. Forty-five patients were enrolled in this study. The median baseline characteristics were as follows: age 67 years, serum IgM 43 g/L, and hemoglobin 102 g/L. Seventeen patients (38%) carried CXCR4 mutations. Nineteen patients (42%) achieved VGPR. Grade 3 or higher adverse events included neutropenia (38%), mucositis (9%), and tumor lysis syndrome (7%). Atrial fibrillation occurred in 3 (9%), and ventricular arrhythmia in 4 (9%) patients that included 2 grade 5 events. With a median follow-up of 24.4 months, the 24-month progression-free survival (PFS) and overall survival (OS) rates were 76% and 96%, respectively, and were not impacted by CXCR4 mutations. The median time on therapy was 10.2 months, and the median time after the end of therapy (EOT) was 13.3 months. Eleven of the 12 progression events occurred after EOT, and the 12-month PFS rates after EOT were 79%; 93% if VGPR was attained, and 69% for other patients (P = .12). Ibrutinib and venetoclax induced high VGPR rates and durable responses after EOT, although they were associated with a higher-than-expected rate of ventricular arrhythmia in patients with WM, leading to early study treatment termination. This trial was registered at www.clinicaltrials.gov as #NCT04273139.

Report of consensus panel 1 from the 11th International Workshop on Waldenstrom's Macroglobulinemia on management of symptomatic, treatment-naïve patients.

Consensus Panel 1 (CP1) of the 11th International Workshop on Waldenstrom's Macroglobulinemia (IWWM-11) was tasked with updating guidelines for the management of symptomatic, treatment-naïve patients with WM. The panel reiterated that watchful waiting remains the gold standard for asymptomatic patients without critically elevated IgM or compromised hematopoietic function. For first-line treatment, chemoimmunotherapy (CIT) regimens such as dexamethasone, cyclophosphamide, rituximab (DRC), or bendamustine, rituximab (Benda-R) continue to play a central role in managing WM, as they are effective, of fixed duration, generally well-tolerated, and affordable. Covalent BTK inhibitors (cBTKi) offer a continuous, generally well-tolerated alternative for the primary treatment of WM patients, particularly those unsuitable for CIT. In a Phase III randomized trial updated at IWWM-11, the second-generation cBTKi, zanubrutinib, was less toxic than ibrutinib and induced deeper remissions, thus categorizing zanubrutinib as a suitable treatment option in WM. While the overall findings of a prospective, randomized trial updated at IWWM-11 did not show superiority of fixed duration rituximab maintenance over observation following attainment of a major response to Benda-R induction, a subset analysis showed benefit in patients >65 years and those with a high IPPSWM score. Whenever possible, the mutational status of MYD88 and CXCR4 should be determined before treatment initiation, as alterations in these 2 genes predict sensitivity towards cBTKi activity. Treatment approaches for WM-associated cryoglobulins, cold agglutinins, AL amyloidosis, Bing-Neel syndrome (BNS), peripheral neuropathy, and hyperviscosity syndrome follow the common principle of reducing tumor and abnormal protein burden rapidly and deeply to improve symptoms. In BNS, ibrutinib can be highly active and produce durable responses. In contrast, cBTKi are not recommended for treating AL amyloidosis. The panel emphasized that continuous improvement of treatment options for symptomatic, treatment-naïve WM patients critically depends on the participation of patients in clinical trials, whenever possible.

Effect of granulocyte colony-stimulating factor on toxicities after CAR T cell therapy for lymphoma and myeloma.

Chimeric antigen receptor T cells (CAR T) are groundbreaking therapies but may cause significant toxicities including cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), and cytopenias. Granulocyte colony-stimulating factor (G-CSF) is often used to mitigate neutropenia after CAR T, but there is no consensus recommended strategy due to hypothesized, but largely unknown risks of exacerbating toxicities. To investigate the impact of G-CSF, we retrospectively analyzed 197 patients treated with anti-CD19 CAR T for lymphoma and 47 patients treated with anti-BCMA CAR T for multiple myeloma. In lymphoma, 140 patients (71%) received prophylactic G-CSF before CAR T (mostly pegylated G-CSF) and were compared with 57 patients (29%) treated with G-CSF after CAR T or not exposed. Prophylactic G-CSF was associated with faster neutrophil recovery (3 vs. 4 days, P < 0.01) but did not reduce recurrent neutropenia later. Prophylactic G-CSF was associated with increased grade ≥2 CRS (HR 2.15, 95% CI 1.11-4.18, P = 0.02), but not ICANS. In multiple myeloma, prophylactic G-CSF was not used; patients were stratified by early G-CSF exposure (≤2 days vs. ≥3 days after CAR T or no exposure), with no significant difference in toxicities. Future trials should clarify the optimal G-CSF strategy to improve outcomes after CAR T.

Quality of life, psychological distress, and prognostic perceptions in caregivers of patients with multiple myeloma.

Although caregivers of patients with multiple myeloma (MM) play a critical role in supporting their loved ones throughout the illness course, studies examining caregiver quality of life (QOL), psychological distress, and prognostic awareness are lacking. We conducted a cross-sectional, multisite study of patients undergoing treatment with MM and their caregivers. Eligible caregivers were enrolled to 1 of 3 cohorts based on lines of therapy. Caregivers completed validated questionnaires to assess their QOL, psychological distress, and perceptions of prognosis. We enrolled 127 caregivers of patients with MM (newly diagnosed [n = 43], 2-3 lines of therapy [n = 40], and ≥4 lines of therapy [n = 44]). Caregiver QOL and psychological distress did not differ by line of therapy. The rate of clinically significant anxiety, depression, and posttraumatic stress disorder symptoms were 44.1% (56/127), 15.8% (20/127), and 24.4% (31/127), respectively. When examined in dyads, caregivers reported higher rates of clinically significant anxiety (44.4% [55/124] vs 22.5% [28/124]) compared with patients with MM. Most caregivers (84.2%, 101/120) reported that the oncologist had informed them that the patient's cancer was incurable; however, only 50.9% (58/114) and 53.6% (59/110) of caregivers acknowledged the patient's cancer was terminal and incurable, respectively. Caregivers of patients undergoing treatment for MM experience substantial psychological distress across the disease continuum, particularly anxiety. The majority of caregivers of patients with MM report that knowing the patient's prognosis is extremely important and report that the oncologist told them that the patient was incurable. Nevertheless, a significant portion of caregivers believe that the patient's MM is curable.

Zanubrutinib for the treatment of adults with Waldenstrom macroglobulinemia.

INTRODUCTION: The development of Bruton tyrosine kinase (BTK) inhibitors has significantly changed the treatment landscape for patients with Waldenström macroglobulinemia (WM). Ibrutinib was the first BTK inhibitor to receive FDA approval for this disease, but in recent years additional more selective BTK inhibitors have become available. Zanubrutinib, the most recently FDA-approved therapy for WM, has demonstrated comparable efficacy regarding hematologic response, but with an improved side effect profile compared to other BTK inhibitors. AREAS COVERED: In this review, we highlight the pivotal studies that have formed the foundation for the use of zanubrutinib in WM, including safety and efficacy data from prospective clinical trials of the currently available BTK inhibitors. EXPERT OPINION: BTK inhibitors are very effective in WM and have an overall response rate higher than 90%. The side effect profile of these medications is manageable but does include a risk of atrial fibrillation, infection, and bleeding. The newer BTK inhibitors, such as acalabrutinib and zanubrutinib, are known to have less off-target effects and are potential treatment options. BTK inhibitors should be considered as a treatment option in treatment-naïve and previously treated disease depending on the individual patient preferences, comorbidities, and molecular profile.

SOHO State of the Art Updates and Next Questions: Targeted therapies and emerging novel treatment approaches for Waldenström Macroglobulinemia.

Waldenström Macroglobulinemia (WM) is a rare hematologic malignancy characterized by the presence of lymphoplasmacytic lymphoma cells involving the bone marrow and production of a monoclonal IgM paraprotein. Recurrent somatic mutations in MYD88L265P and CXCR4 have been reported in 90% to 95% and 30% to 40% of patients with WM, respectively. Standard treatment regimens combine the anti-CD20 antibody rituximab with alkylating agents (eg, bendamustine, cyclophosphamide), nucleoside analogs (eg, fludarabine, cladribine), or proteasome inhibitors (eg, bortezomib, carfilzomib, and ixazomib). Covalent BTK inhibitors (eg, ibrutinib, acalabrutinib, zanubrutinib) have shown to be safe and highly effective in patients with WM. Novel and promising agents in this disease include next-generation covalent BTK inhibitors (eg, tirabrutinib, orelabrutinib), non-covalent BTK inhibitors (eg, pirtobrutinib, ARQ531), BCL-2 antagonists (eg, venetoclax), and CXCR4-targeted agents (eg, mavorixafor, ulocuplumab), among others. Future studies will focus on developing fixed-duration combinations regimens with these novel agents aimed at increasing durable responses while minimizing toxicity and cost.

A new role for the SRC family kinase HCK as a driver of SYK activation in MYD88 mutated lymphomas.

The SRC family kinase (SFK) HCK is transcriptionally upregulated and activated by mutated MYD88 (MYD88Mut), a key adaptor for Toll-receptor signaling. HCK activates BTK, AKT, and ERK in MYD88Mut lymphomas. SYK, a B-cell receptor (BCR) component, is activated in MYD88Mut lymphoma cells. Although the SFK LYN serves as a trigger for SYK activation in MYD88Mut ABC DLBCL cells, LYN activity is muted in MYD88Mut Waldenstrom macroglobulinemia (WM) cells. We therefore investigated a role for HCK in mediating SYK activation. Overexpression of wild-type (WT) (HCKWT) or gatekeeper mutated (HCKThr333Met) HCK in MYD88Mut lymphoma cells triggered SYK activation. Conversely, HCK knockdown reduced p-SYK in MYD88Mut lymphoma cells. Coimmunoprecipitation experiments showed that HCK was complexed with p-SYK in MYD88Mut BCWM.1 and TMD8 cells, but not in MYD88 WT Ramos cells. Rescue experiments in MYD88Mut lymphoma cells expressing HCKThr333Met led to persistent HCK and SYK activation and resistance to the HCK inhibitor A419259. Treatment of primary MYD88Mut WM cells with A419259 reduced p-HCK and p-SYK expression. Taken together, our findings show that SYK is activated by HCK in MYD88Mut B-cell lymphomas cells, broaden the prosurvival signaling generated by aberrant HCK expression in response to MYD88Mut, and help define HCK as an important therapeutic target in MYD88Mut B-cell lymphomas.

Quality of life, psychological distress, and prognostic perceptions in patients with multiple myeloma.

BACKGROUND: Multiple myeloma (MM) is an incurable hematologic malignancy requiring long-term, continuous therapy. Despite its chronic and unrelenting course, studies examining quality of life (QOL), psychological distress, and perceptions of prognosis by line of therapy are lacking. METHODS: The authors conducted a cross-sectional, multisite study of patients undergoing treatment for MM (excluding maintenance) between June 2020 and January 2021. The authors conducted purposeful sampling and recruited patients to 3 cohorts based on lines of therapy: 1) newly diagnosed receiving first-line therapy; 2) 2 to 3 lines; and 3) 4 or more lines. Patients completed validated questionnaires to assess their QOL, fatigue, psychological distress, and perceptions of prognosis. RESULTS: A total of 180 patients with MM were enrolled (newly diagnosed [n = 60], 2 to 3 lines [n = 60], and ≥4 lines of therapy [n = 60]). QOL, symptom burden, and fatigue scores did not differ by lines of therapy. There were no statistically significant differences in psychological distress by line of therapy. The rates of clinically significant depression, anxiety, and post-traumatic stress disorder symptoms were 23.9% (43 of 180), 23.9% (43 of 180), and 24.4% (44 of 180), respectively. Most patients (84.7%, 149 of 176) reported that their oncologist told them their cancer was incurable, but only 30.6% (53 of 173) acknowledged that they were terminally ill, and 42.0% (73 of 174) reported that they thought their cancer was incurable. CONCLUSIONS: Patients with MM undergoing treatment experience impaired QOL and elevated psychological distress across the disease continuum, regardless of line of therapy. A substantial proportion of patients with MM have significant misperceptions about their prognosis and the curability of their illness despite reporting being informed of the prognosis by their oncologist. LAY SUMMARY: This study discusses 180 patients with MM (newly diagnosed [n = 60], 2-3 lines [n = 60], and ≥4 lines of therapy [n = 60]). Quality of life, symptom burden, and fatigue scores do not differ by lines of therapy. There are also no statistically significant differences in psychological distress by line of therapy. The rates of clinically significant depression, anxiety, and post-traumatic stress disorder symptoms are 23.9%, 23.9%, and 24.4%, respectively. Most patients (84.7%) report that their oncologist told them their cancer was incurable, but only 30.6% acknowledge that they are terminally ill, and 42.0% report that they thought their cancer was incurable.

Long-term follow-up of ibrutinib monotherapy in treatment-naive patients with Waldenstrom macroglobulinemia.

Herein, we present the final report of a single-center, prospective phase II study evaluating ibrutinib 420 mg once daily in 30 treatment-naive patients with Waldenstrom macroglobulinemia (WM). The present study is registered with ClinicalTrials.Gov (NCT02604511). With a median follow-up of 50 months, the overall, major, and VGPR response rates were 100%, 87%, and 30%. The VGPR rate was numerically but not significantly lower in patients with than without CXCR4 mutations (14% vs. 44%; p = 0.09). The median time to a minor response was 0.9 months, and to a major response was 1.9 months, though were longer in those with mutated CXCR4 at 1.7 months (p = 0.07) and 7.3 months (p = 0.01). Six patients had disease progression. The median progression-free survival (PFS) was not reached, and the 4-year PFS rate was 76%. There was also a non-significant lower 4-year PFS rate in patients with than without CXCR4 mutations (59% vs. 92%; p = 0.06). The most common treatment-related adverse events were fatigue, upper respiratory infection, and hematoma. Atrial fibrillation occurred in 20% of patients. Ibrutinib monotherapy induced durable responses in treatment-naive patients with WM. CXCR4 mutations impacted VGPR attainment, time to major response, and 4-year PFS rate.

Natural history of Waldenström macroglobulinemia following acquired resistance to ibrutinib monotherapy.

Ibrutinib is highly active and produces long-term responses in patients with Waldenström macroglobulinemia (WM), but acquired resistance can occur with prolonged treatment. We therefore evaluated the natural history and treatment outcomes in 51 WM patients with acquired resistance to ibrutinib monotherapy. The median time between ibrutinib initiation and discontinuation was 2 years (range, 0.4-6.5 years). Following discontinuation of ibrutinib, a rapid increase in serum immunoglobulin M level was observed in 60% (29/48) of evaluable patients, of whom ten acutely developed symptomatic hyperviscosity. Forty-eight patients (94%) received salvage therapy after ibrutinib. The median time to salvage therapy after ibrutinib cessation was 18 days (95% confidence interval [CI]: 13-27). The overall and major response rates to salvage therapy were 56% and 44%, respectively, and the median duration of response was 48 months (95% CI: 34-not reached). Quadruple-class (rituximab, alkylator, proteasome inhibitor, ibrutinib) exposed disease (odds ratio [OR] 0.20, 95% CI: 0.05-0.73) and salvage therapy ≤7 days after discontinuing ibrutinib (OR 4.12, 95% CI: 1.07- 18.9) were identified as independent predictors of a response to salvage therapy. The 5-year overall survival (OS) following discontinuation of ibrutinib was 44% (95% CI: 26-75). Response to salvage therapy was associated with better OS after ibrutinib (hazard ratio 0.08, 95% CI: 0.02-0.38). TP53 mutations were associated with shorter OS, while acquired BTK C481S mutations had no impact. Our findings reveal that continuation of ibrutinib until subsequent treatment is associated with improved disease control and clinical outcomes.

Venetoclax in Previously Treated Waldenström Macroglobulinemia.

PURPOSE: BCL2 is overexpressed and confers prosurvival signaling in malignant lymphoplasmacytic cells in Waldenström macroglobulinemia (WM). Venetoclax is a potent BCL2 antagonist and triggers in vitro apoptosis of WM cells. The activity of venetoclax in WM remains to be clarified. PATIENTS AND METHODS: We performed a multicenter, prospective phase II study of venetoclax in patients with previously treated WM (NCT02677324). Venetoclax was dose-escalated from 200 mg to a maximum dose of 800 mg daily for up to 2 years. RESULTS: Thirty-two patients were evaluable, including 16 previously exposed to Bruton tyrosine kinase inhibitors (BTKis). All patients were MYD88 L265P-mutated, and 17 carried CXCR4 mutations. The median time to minor and major responses was 1.9 and 5.1 months, respectively. Previous exposure to BTKis was associated with a longer time to response (4.5 v 1.4 months; P < .001). The overall, major, and very good partial response rates were 84%, 81%, and 19%, respectively. The major response rate was lower in those with refractory versus relapsed disease (50% v 95%; P = .007). The median follow-up time was 33 months, and the median progression-free survival was 30 months. CXCR4 mutations did not affect treatment response or progression-free survival. The only recurring grade ≥ 3 treatment-related adverse event was neutropenia (n = 14; 45%), including one episode of febrile neutropenia. Laboratory tumor lysis without clinical sequelae occurred in one patient. No deaths have occurred. CONCLUSION: Venetoclax is safe and highly active in patients with previously treated WM, including those who previously received BTKis. CXCR4 mutation status did not affect treatment response.

Response and survival predictors in a cohort of 319 patients with Waldenström macroglobulinemia treated with ibrutinib monotherapy.

Bruton tyrosine kinase (BTK) inhibitors are the only FDA-approved treatments for Waldenström macroglobulinemia (WM). Factors prognostic of survival and predictive of response to BTK inhibitors remained to be clarified. We evaluated 319 patients with WM to identify predictive and prognostic factors on ibrutinib monotherapy. Logistic and Cox proportional-hazard regression models were fitted for response and survival. Multiple imputation analyses were used to address bias associated with missing data. Major (partial response or better) and deep responses (very good partial response or better) were attained in 78% and 28% of patients. CXCR4 mutations were associated with lower odds of major (odds ratio [OR], 0.2; 95% confidence interval [CI], 0.1-0.5; P < .001) and deep response (OR, 0.3; 95% CI, 0.2-0.6; P = .001). CXCR4 mutations (hazard ratio [HR], 2.0; 95% CI, 1.2-3.4; P = .01) and platelet count 100 K/uL or less (HR, 2.5; 95% CI, 1.3-4.9; P = .007) were associated with worse progression-free survival (PFS). We proposed a scoring system using these 2 factors. The median PFS for patients with 0, 1, and 2 risk factors were not reached, 5 years and 3 years (P < .001). Patients with 2 risk factors had HR 2.2 (95% CI, 1.3-3.8; P = .004) compared with 1 factor, and patients with 1 factor had HR 2.3 (95% CI, 1.1-5.1; P = .03) compared with 0 factors. Age ≥65 years was the only factor associated with overall survival (HR, 3.2; 95% CI, 1.4-7.0; P = .005). Multiple imputation analyses did not alter our results. Our study confirms the predictive and prognostic value of CXCR4 mutations in patients with WM treated with ibrutinib monotherapy.

Lifestyle considerations in multiple myeloma.

As the prognosis for multiple myeloma (MM) has significantly improved and patients remain on therapy longer, there is a need for supportive care interventions to optimize patient quality of life (QOL) and functional status over the course of cancer treatment. MM is characterized by a significant symptom burden and a relatively lower QOL compared to other cancers. This review evaluates the role of healthy lifestyle behaviors in improving both the physical functioning and psychological well-being of the MM population. We (1) describe the current literature on physical activity, weight management, diet, sleep, and substance use in the context of MM, (2) present important considerations for incorporating lifestyle factors into clinical practice, and (3) identify directions for future research. Developing MM-specific guidelines for modifiable lifestyle changes that take into account both the length of treatment and the unique disease features (i.e. osteolytic lesions and anemia) may provide a promising path for improved patient QOL and functioning.

Phase 1 study of ibrutinib and the CXCR4 antagonist ulocuplumab in CXCR4-mutated Waldenström macroglobulinemia.

MYD88 and CXCR4 mutations are common in Waldenström macroglobulinemia (WM). Mutated CXCR4 (CXCR4Mut) impacts BTK-inhibitor response. We conducted a phase 1 trial of the CXCR4-antagonist ulocuplumab with ibrutinib in this first-ever study to target CXCR4Mut in WM. Ibrutinib was initiated at 420 mg/d with cycle 1 and continued until intolerance or progression; ulocuplumab was given cycles 1 to 6, with a 3 + 3 dose-escalation design. Each cycle was 4 weeks. Thirteen symptomatic patients, of whom 9 were treatment-naive patients were enrolled. Twelve were evaluable for response. At best response, their median serum immunoglobulin M declined from 5574 to 1114 mg/dL; bone marrow disease decreased from 65% to 10%, and hemoglobin increased from 10.1 to 14.2 g/dL (P < .001). The major and VGPR response rates were 100% and 33%, respectively, with VGPRs observed at lower ulocuplumab dose cohorts. Median times to minor and major responses were 0.9 and 1.2 months, respectively. With a median follow-up of 22.4 months, the estimated 2-year progression-free survival was 90%. The most frequent recurring grade ≥2 adverse events included reversible thrombocytopenia, rash, and skin infections. Ulocuplumab dose-escalation did not impact adverse events. The study demonstrates the feasibility of combining a CXCR4-antagonist with ibrutinib and provides support for the development of CXCR4-antagonists for CXCR4Mut WM. This trial was registered at www.clinicaltrials.gov as #NCT03225716.

Bone marrow involvement and subclonal diversity impairs detection of mutated CXCR4 by diagnostic next-generation sequencing in Waldenström macroglobulinaemia.

CXCR4 mutations impact disease presentation and treatment outcomes in Waldenström macroglobulinaemia (WM). Non-uniform testing for CXCR4 mutations may account for discordant findings in WM clinical trials. We compared two approaches used in these trials for detection of the most common CXCR4 (S338X) variant: targeted next-generation sequencing (NGS) using unselected bone marrow (BM) samples, and combined allele-specific polymerase chain reaction (AS-PCR) and Sanger sequencing with unselected and CD19-selected BM samples. Our findings showed that targeted NGS frequently yielded false-negative results. Both CD19 selection and AS-PCR markedly improved detection of CXCR4S338X mutations. Sensitivity was adversely impacted by low BM involvement and CXCR4 mutation clonality.

Tandem high-dose influenza vaccination is associated with more durable serologic immunity in patients with plasma cell dyscrasias.

Patients with plasma cell dyscrasias (PCDs) experience an increased burden of influenza, and current practice of single-dose annual influenza vaccination yields suboptimal protective immunity in these patients. Strategies to improve immunity to influenza in these patients are clearly needed. We performed a randomized, double-blind, placebo-controlled clinical trial comparing tandem Fluzone High-Dose influenza vaccination with standard-of-care influenza vaccination. Standard-of-care vaccination was single-dose age-based vaccination (standard dose, <65 years; high dose, ≥65 years), and patients in this arm received a saline placebo injection at 30 days. A total of 122 PCD patients were enrolled; 47 received single-dose standard-of-care vaccination, and 75 received 2 doses of Fluzone High-Dose vaccine. Rates of hemagglutinin inhibition (HAI) titer seroprotection against all 3 strains (H1N1, H3N2, and influenza B) were significantly higher for patients after tandem high-dose vaccination vs control (87.3% vs 63.2%; P = .003) and led to higher seroprotection at the end of flu season (60.0% vs 31.6%; P = .04). These data demonstrate that tandem high-dose influenza vaccination separated by 30 days leads to higher serologic HAI titer responses and more durable influenza-specific immunity in PCD patients. Similar vaccine strategies may also be essential to achieve protective immunity against other emerging pathogens such as novel coronavirus in these patients. This trial was registered at www.clinicaltrials.gov as #NCT02566265.