Clinical and clonal characteristics of monoclonal immunoglobulin M-associated type I cryoglobulinaemia.

Monoclonal immunoglobulin M-associated type I cryoglobulinaemia is poorly characterised. We screened 534 patients with monoclonal IgM disorders over a 9-year period and identified 134 patients with IgM type I cryoglobulins. Of these, 76% had Waldenström macroglobulinaemia (WM), 5% had other non-Hodgkin lymphoma (NHL) and 19% had IgM monoclonal gammopathy of undetermined significance (MGUS). Clinically relevant IgM-associated disorders (including cold agglutinin disease [CAD], anti-MAG antibodies, amyloidosis and Schnitzler syndrome) coexisted in 31%, more frequently in MGUS versus WM/NHL (72% vs. 22%/29%, p < 0.001). The majority of those with cryoglobulins and coexistent CAD/syndrome had the molecular characteristics of a CAD clone (wild-type MYD88 in 80%). A half of all patients had active manifestations at cryoglobulin detection: vasomotor (22%), cutaneous (16%), peripheral neuropathy (22%) and hyperviscosity (9%). 16/134 required treatment for cryoglobulin-related symptoms alone at a median of 38 days (range: 6-239) from cryoglobulin detection. At a median follow-up of 3 years (range: 0-10), 3-year cryoglobulinaemia-treatment-free survival was 77% (95% CI: 68%-84%). Age was the only predictor of overall survival. Predictors of cryoglobulinaemia-related treatment/death were hyperviscosity (HR: 73.01; 95% CI: 15.62-341.36, p < 0.0001) and cutaneous involvement (HR: 2.95; 95% CI: 1.13-7.71, p = 0.028). Type I IgM cryoglobulinaemia is more prevalent than previously described in IgM gammopathy and should be actively sought.

PembroWM: A phase II trial to investigate the safety and efficacy of rituximab and pembrolizumab in relapsed/refractory Waldenström's Macroglobulinaemia.

The optimal therapeutic approach for relapsed/refractory (R/R) Waldenström's Macroglobulinaemia (WM) has not been clearly defined, especially after treatment with chemoimmunotherapy (CIT) and covalent Bruton's tyrosine kinase inhibitors (cBTKi). The PembroWM trial is a multi-centre, phase II, single-arm study assessing the safety, tolerability and efficacy of rituximab with pembrolizumab in R/R WM patients who had received at least one prior line of treatment, with all having relapsed post-CIT and most also exposed to cBTKi. A total of 17 patients were enrolled, with a median age of 70, and median of three prior lines of therapy with 15 either refractory or intolerant of a cBTKi. A significant proportion was identified as genomically high risk with BTKC481, CXCR4 and MYD88 L265P wild-type aberrations. Twenty-four-week overall response rate was 50% (60% CI 39.3%-60.7%), and median duration of response was 11.6 months (IQR: 6.3-17). The median progression-free survival was 13.6 months (95% CI 3-19.8), and the median overall survival (OS) was not reached. Treatment was well tolerated, with minimal numbers of immune-mediated AEs typically seen with checkpoint inhibitors. PembroWM is the first study to evaluate the feasibility of PD-1 axis modulation in WM and has shown that in combination with Rituximab the combination is safe and deliverable.

Fatigue, quality of life and physical fitness following an exercise intervention in multiple myeloma survivors (MASCOT): an exploratory randomised Phase 2 trial utilising a modified Zelen design.

BACKGROUND: Exercise may improve fatigue in multiple myeloma survivors, but trial evidence is limited, and exercise may be perceived as risky in this older patient group with osteolytic bone destruction. METHODS: In this Phase 2 Zelen trial, multiple myeloma survivors who had completed treatment at least 6 weeks ago, or were on maintenance only, were enrolled in a cohort study and randomly assigned to usual care or a 6-month exercise programme of tailored aerobic and resistance training. Outcome assessors and usual care participants were masked. The primary outcome was the FACIT-F fatigue score with higher scores denoting less fatigue. RESULTS: During 2014-2016, 131 participants were randomised 3:1 to intervention (n = 89) or usual care (n = 42) to allow for patients declining allocation to the exercise arm. There was no difference between groups in fatigue at 3 months (between-group mean difference: 1.6 [95% CI: -1.1-4.3]) or 6 months (0.3 [95% CI: -2.6-3.1]). Muscle strength improved at 3 months (8.4 kg [95% CI: 0.5-16.3]) and 6 months (10.8 kg [95% CI: 1.2-20.5]). Using per-protocol analysis, cardiovascular fitness improved at 3 months (+1.2 ml/kg/min [95% CI: 0.3-3.7]). In participants with clinical fatigue (n = 17), there was a trend towards less fatigue with exercise over 6 months (6.3 [95% CI: -0.6-13.3]). There were no serious adverse events. CONCLUSIONS: Exercise appeared safe and improved muscle strength and cardiovascular fitness, but benefits in fatigue appeared limited to participants with clinical fatigue at baseline. Future studies should focus on patients with clinical fatigue. CLINICAL TRIAL REGISTRATION: The study was registered with ISRCTN (38480455) and is completed.

Whole body magnetic resonance imaging in newly diagnosed multiple myeloma: early changes in lesional signal fat fraction predict disease response.

Cross-sectional imaging techniques are being increasingly used for disease evaluation in patients with multiple myeloma. Whole body magnetic resonance imaging (WB-MRI) scanning is superior to plain radiography in baseline assessment of patients but changes following treatment have not been systematically explored. We carried out paired WB-MRI scans in 21 newly diagnosed patients prior to, and 8-weeks after, starting chemotherapy, and analysed stringently selected focal lesions (FLs) for parametric changes. A total of 323 FLs were evaluated, median 20 per patient. At 8 weeks, there was a reduction in estimated tumour volume (eTV), and an increase in signal fat fraction (sFF) and apparent diffusion coefficient (ADC) in the group as a whole (P < 0·001). Patients who achieved complete/very good partial response (CR/VGPR) to induction had a significantly greater increase in sFF compared to those achieving ≤ partial response (PR; P = 0·001). When analysed on a per-patient basis, all patients achieving CR/VGPR had a significant sFF increase in their FL's, in contrast to patients achieving ≤PR. sFF changes in patients reaching maximal response within 100 days (fast responders) were greater compared to slow responders (P = 0·001). Receiver Operator Characteristic analysis indicated that sFF changes at 8 weeks were the best biomarker (area under the Curve 0·95) for an inferior response (≤PR). We conclude that early lesional sFF changes may provide important information on depth of response, and are worthy of further prospective study.

Real-world use of pomalidomide and dexamethasone in double refractory multiple myeloma suggests benefit in renal impairment and adverse genetics: a multi-centre UK experience.

Myeloma patients who become refractory to immunomodulatory agents (IMiDs) and bortezomib have poor survival, with limited therapeutic options. Pomalidomide has shown improved survival and good tolerability in this patient cohort in clinical trials, but real world data are scarce. We retrospectively analysed all patients treated with pomalidomide at five UK centres between 2013 and 2016. Of 85 patients identified, 70 had sufficient information for response assessments. Median age was 66 years [40-89], 96·5% were refractory to IMiDs, 72·9% were refractory to both an IMiD and bortezomib and 92·9% were refractory to their last treatment. Of 45 patients with fluorescence in situ hybridization results 64% had adverse risk, 19 patients (22·4%) had an estimated glomerular filtration rate <45 ml/min. Grade ≥3 non-haematological toxicities occurred in 42·4%, and grade ≥3 neutropenia and thrombocytopenia in 38% and 24% respectively, but only 18·8% had dose reductions. The overall response rate was 52·9%. At a median follow-up of 13·2 months, median progression-free survival was 5·2 months [95% confidence interval (CI) 4·150-6·238], and median overall survival was 13·7 months (95% CI 11·775-15·707). No significant difference was seen in response, survival or tolerability by renal function, age or cytogenetic risk. This real-world data support the results seen in published clinical trials.

Whole-body MRI quantitative biomarkers are associated significantly with treatment response in patients with newly diagnosed symptomatic multiple myeloma following bortezomib induction.

OBJECTIVES: To evaluate whole-body MRI (WB-MRI) parameters significantly associated with treatment response in multiple myeloma (MM). METHODS: Twenty-one MM patients underwent WB-MRI at diagnosis and after two cycles of chemotherapy. Scans acquired at 3.0 T included T2, diffusion-weighted-imaging (DWI) and mDixon pre- and post-contrast. Twenty focal lesions (FLs) matched on DWI and post-contrast mDixon were selected for each time point. Estimated tumour volume (eTV), apparent diffusion coefficient (ADC), enhancement ratio (ER) and signal fat fraction (sFF) were derived. Clinical treatment response to chemotherapy was assessed using conventional criteria. Significance of temporal parameter change was assessed by the paired t test and receiver operating characteristics/area under the curve (AUC) analysis was performed. Parameter repeatability was assessed by interclass correlation (ICC) and Bland-Altman analysis of 10 healthy volunteers scanned at two time points. RESULTS: Fifteen of 21 patients responded to treatment. Of 254 FLs analysed, sFF (p < 0.0001) and ADC (p = 0.001) significantly increased in responders but not non-responders. eTV significantly decreased in 19/21 cases. Focal lesion sFF was the best discriminator of treatment response (AUC 1.0). Bone sFF repeatability was excellent (ICC 0.98) and better than bone ADC (ICC 0.47). CONCLUSION: WB-MRI derived focal lesion sFF shows promise as an imaging biomarker of treatment response in newly diagnosed MM. KEY POINTS: • Bone signal fat fraction using mDixon is a robust quantifiable parameter • Fat fraction and ADC significantly increase in myeloma lesions responding to treatment • Bone lesion fat fraction is the best discriminator of myeloma treatment response.

Patient reported outcome measures in Waldenström macroglobulinaemia: A real-world data analysis from the WMUK Rory Morrison Registry.

Waldenström macroglobulinaemia (WM) is an incurable chronic B-cell malignancy, but highly responsive to treatment. Treatments include fixed-duration chemotherapy and continuous oral chemoimmunotherapy. In this expanding field, it is important to have reliable information on the impact of the various therapies on patients' quality of life (QoL). Patient reported outcome measures (PROMs) are increasingly recognised as important to understand patient experience of disease beyond traditional clinical outcome measures. Four QoL questionnaires (EORTC QLQ-C30 [European Organisation for Research and Treatment of Cancer quality of life core questionnaire], BIPQ [Brief Illness Perception Questionnaire], HADS [Hospital Anxiety and Depression Scale], EQ-5D-5L [EuroQoL 5-dimensional descriptive system questionnaire]) are embedded in the UK national WM registry, the Rory Morrison Registry. We reviewed the results from a snapshot of PROMs. As of November 2021, 155 patients completed PROM data with 98% completion rate across all 58 questions. Complete clinical information was available for 52 patients. The majority of QoL questions (69%) failed to elicit a notable median response. Only four questions elicited statistically significant responses when comparing groups, and these were exclusively found in the EuroQoL-5D-5L and HADS questionnaires. Our data suggest that widely used questionnaires may not be suitable for patients with WM. We advocate the development of WM-specific outcome measures to overcome this.

Bortezomib-based therapy is effective and well tolerated in frontline and multiply pre-treated Waldenström macroglobulinaemia including BTKi failures: A real-world analysis.

Waldenström macroglobulinemia (WM) is a rare, incurable low grade lymphoma following a relapsing trajectory. Management strategies have evolved with the introduction of targeted therapy including new classes of Bruton tyrosine kinase inhibitor (BTKi). Treatment may however be limited particularly at relapse by a lack of drug availability and tolerability. We assessed the real-world efficacy and tolerability of bortezomib-containing regimens in patients with WM at frontline and relapse including those with prior BTKi resistance. Forty-one patients were identified with 44 bortezomib-containing regimens administered (n = 12 frontline, n = 32 relapse). Of patients treated at relapse, the median prior lines of therapy was 3 (range 1-7). 24% (10/41) of the cohort were refractory or intolerant to BTKi prior to bortezomib delivery. The median follow-up after bortezomib administration was 34 months (range 0-131). Overall response rate was 88%; 2-year overall survival and progression-free survival were 90% (95% confidence interval [CI] 73-96) and 76% (95% CI 55-87), respectively. Median time-to-next-treatment was 66 months. Neuropathy (grade 1-2) occurred in 24% (8/34) and did not result in treatment cessation in any case. Gastrointestinal disturbance occurred in 7% (3/41). Treatment discontinuations were rare (1/44; 2%), suggesting a manageable safety profile. Major response rate was comparable in those with prior BTKi compared with those without (75% [6/8] vs 84% [27/32], p = 0.61). Bortezomib should be considered as a treatment modality particularly in those who are refractory to BTKi.

Recurrent activating STAT5B N642H mutation in myeloid neoplasms with eosinophilia.

Determining the underlying cause of persistent eosinophilia is important for effective clinical management but remains a diagnostic challenge in many cases. We identified STAT5B N642H, an established oncogenic mutation, in 27/1715 (1.6%) cases referred for investigation of eosinophilia. Of the 27 mutated cases, a working diagnosis of hypereosinophilic syndrome (HES; n = 7) or a myeloid neoplasm with eosinophilia (n = 20) had been made prior to the detection of STAT5B N642H. Myeloid panel analysis identified a median of 2 additional mutated genes (range 0-4) with 4 cases having STAT5B N642H as a sole abnormality. STAT5B N642H was absent in cultured T cells of 4/4 positive cases. Individuals with SF3B1 mutations (9/27; 33%) or STAT5B N642H as a sole abnormality had a markedly better overall survival compared to cases with other additional mutations (median 65 months vs. 14 months; hazard ratio = 8.1; P < 0.001). The overall survival of STAT5B-mutated HES cases was only 30 months, suggesting that these cases should be reclassified as chronic eosinophilic leukemia, not otherwise specified (CEL-NOS). The finding of STAT5B N642H as a recurrent mutation in myeloid neoplasia with eosinophilia provides a new diagnostic and prognostic marker as well as a potential target for therapy.