Leung, Nelson

PURPOSE Limited evidence exists regarding methotrexate (MTX) resumption after patients with lymphoma receive glucarpidase for toxic MTX levels and acute kidney injury (AKI). METHODS This retrospective review included adults with lymphoma treated with glucarpidase after MTX at Mayo Clinic between January 31, 2020, and October 10, 2022. Descriptive statistics summarize patient characteristics and clinical outcomes. RESULTS Of 11 patients treated with glucarpidase after MTX, seven (64%) were rechallenged with MTX. Indications for MTX rechallenge included confirmed CNS disease (n = 6, 86%) and intravascular lymphoma (n = 1, 14%). Compared with the nonrechallenged subgroup, before receiving MTX that required glucarpidase rescue, the rechallenged patients had lower median pretreatment serum creatinine (Scr; 0.7 v 1.2 mg/dL), and none had AKI with previous MTX doses, n = 0 (0%) versus n = 2 (50%). During the MTX dose requiring glucarpidase rescue, the rechallenged group had lower median peak Scr (1.26 v 3.32 mg/dL) and lower incidence of AKI stage III (n = 1 [14%] v n = 3 [75%]), and none of the rechallenged patients required renal replacement therapy (RRT; n = 0 [0%] v n = 1 [25%]). At the first rechallenge after glucarpidase administration, the median MTX dose reduction was 56% (range, 46%-75%), and the lowest used dose when prescribed according to each treatment protocol schedule was 1.5 g/m2. Two (29%) patients experienced AKI (n = 1 stage I, n = 1 stage II) after MTX rechallenge. Zero patients required RRT, and zero required another glucarpidase administration. Six (86%) patients completed all recommended MTX doses. CONCLUSION In selected adults with lymphoma who required glucarpidase for toxic MTX levels after administration of high-dose MTX, resumption of MTX therapy at lower doses is safe. Patients selected for MTX resumption had experienced less severe AKI during the previous cycle compared with those not selected for MTX resumption.

Background:Waldenström Macroglobulinemia (WM) is a rare, indolent B‐cell lymphoplasmacytic malignancy. Patient outcomes are highly heterogeneous, with a proportion of patients surviving less than 5 years (short survivors) and another proportion that survive longer than 10 years. The laboratory parameters in the currently used International Prognostic Scoring System for WM (IPSSWM) include hemoglobin, serum IgM, platelet count, and serum β2‐microglobulin.Aims:We aim to identify unique patient characteristics and prognostic features associated with short survival in WM.Methods:The medical records of patients with active WM that were diagnosed at Mayo Clinic Rochester, Arizona, and Florida between January 1st, 1996 and December 31st, 2013 were reviewed. The patients with smoldering WM were excluded. Cohorts of patients who either survived ≤ 5 years (Short Survival Group) or those with an overall survival (OS) ≥ 10 years (Long Survival Group) from the diagnosis of active disease were compared. Survivors with a follow‐up of ≤ 5 years were not included in the analyses. Two‐sided Wilcoxon rank sum test and Chi square/Fisher's exact test were used to compare the continuous and categorical variables, respectively. The variables that were statistically significant on univariate analysis (P < 0.05) were included in a multivariate logisitic regression analysis.Results:Of 893 consecutively seen WM patients (median follow‐up of 9 years [95% CI 8.4–9.7]), we identified 387 patients who could be categorized into either the Short Survival Group (n = 171 patients, 44%) or the Long Survival Group (n = 216, 56%). The Short Survival Group had a median OS of 2.4 years (2.1–2.8) and median age at diagnosis of 73 years (42–93), while the Long Survival Group (n = 216, 56%) had a median OS of 18.9 years (16‐NR) and median age at diagnosis of 62 years (31–85). The baseline characteristics and significant findings between the two groups are listed in the Table. Parameters significant on univariate analysis included age >65 years, albumin < 3.5 g/dL, β2‐microglobulin >3 μg/ml, and LDH > upper limit of normal (ULN). On multivariate analysis, albumin <3.5 g/dL and LDH > ULN were independently associated with short survival. Among the Long Survivors, 60 (28%) patients survived 15 years or more.Summary/Conclusion:Lactate dehydrogenase above the ULN and serum albumin <3.5 g/dL are independent biomarkers of short survival in WM. The MYD88 L265P status and the size of serum IgM are not prognostic in WM. Our data suggest the need for simplification of the current staging system with the use of widely available markers: serum albumin and lactate dehydrogenase.image

We identified a patient with a recently described syndrome, monoclonal gammopathy of thrombotic significance (MGTS; Blood. 2023 Apr 6;141(14):1772-1776), and three additional patients with high 4Ts scores who were consistently negative in the PF4-polyanion HIT ELISA (Lifecodes PF4 IgG, Immucor). The MGTS patient, with a monoclonal IgG kappa, had recurrent thrombosis, and transient mild thrombocytopenia (nadir in the low 100s) over a period of years, and was noted to have a HIT ELISA optical density (OD) of 0.117. The three HIT patients experienced thrombocytopenia and thrombosis with ELISA ODs of 0.37, 0.18 and 0.20. All patients were positive in platelet-activation (functional) testing demonstrating PF4 dependence and inhibited with both high concentrations of heparin (100U/mL) and the FcγRIIa blocking monoclonal antibody (mAb) IV.3, consistent with the presence of anti-PF4 antibodies in the patient samples ( data not shown). Because the serologic profile of these patients suggested a novel HIT subtype characterized by negative HIT ELISA results, we undertook a functional platelet assay screen of 500 consecutive HIT ELISA-negative patients tested in our diagnostic laboratory. Research studies were approved by the Institutional Review Board of Mayo Clinic. Of the 500 patients tested, 20 (4.0%) stimulated platelet activation in the PF4-dependent P-selectin Expression Assay (PEA ≥19%; data not shown). To exclude non-specific activation that can be induced by HLA antibodies, additional testing was performed to evaluate whether platelet activation was PF4-dependent using buffer or PF4-treated platelets. Three patients demonstrated PF4-dependent activation that was inhibited by high heparin concentrations and mAb IV.3, as would be expected for HIT antibodies (ELISA-negative HIT, EN-HIT1-3; Figure 1). On retrospective review, all three patients thus identified had clinical histories and courses consistent with high clinical probability for HIT. To develop tools to study this new class of antibodies, monoclonal HIT antibodies were generated in mice after PF4/heparin immunizations and screened using a novel approach that included simultaneous testing of hybridoma supernatants in the PEA and PF4-polyanion ELISA. This strategy was designed to enabled us to identify mAbs that activated platelets (in the PEA), but that did not bind antigenic targets in the HIT ELISA. A novel mAb 431.4 that was developed using this approach, and the well-characterized HIT-like mAb KKO were evaluated for their abilities to both bind PF4-polyanion targets in ELISA, and to activate PF4-treated platelets in the PEA (Figure 2). In significant contrast to KKO, mAb 431.4 did not bind PF4/polyanion complexes, however, like KKO, strongly activated platelets in a PF4-dependent manner. Activation induced by both KKO and mAb 431.4 was inhibited by high heparin concentrations, as would be expected for HIT antibodies. In vivo murine studies using this novel mAb are pending at this time. In summary, the non-canonical diagnostic profile of HIT ELISA-negative but platelet activation-positive antibodies were found at a relatively high incidence in HIT-suspected patients (0.6%; 3 of 500 ELISA-negative patients). These findings have important diagnostic/management implications and suggest a re-evaluation of ASH's HIT management guidelines as noted in recommendations 2.7 and 2.8 of that document (“In patients with an intermediate (Recommendation 2.7) or high (Recommendation 2.8)-probability 4Ts score and a negative immunoassay, the ASH guideline panel recommends discontinuation of the non-heparin anticoagulant and resumption of heparin, if indicated ”; Blood Adv (2018) 2 (22): 3360-3392). Figure 1. A subset of ELISA-negative HIT-suspected patients harbor anti-PF4 platelet-activating antibodies. Three ELISA-negative (EN) HIT patient samples from a screen of 500 samples demonstrate PF4-dependent platelet activation and inhibition with high heparin concentration and mAb IV.3 incubation. PBS, phosphate buffered saline; IC, isotype control; HDH- high dose heparin (100U/mL). Figure 2. Murine mAb 431.4 serologically mimics pathogenic ELISA-negative HIT/MGTS antibodies. ELISA and PEA testing was performed using the “HIT-like” mAb KKO, novel mAb 431.4, or an isotype control (IC) antibody. PVS-polyvinyl sulfonate (polyanion used in the Immucor IgG ELISA assay).

Abstract Most patients with solitary bone plasmacytomas (SBP) progress to multiple myeloma (MM) after definitive radiation therapy as their primary treatment. Whether the presence of high-risk (HR) cytogenetic abnormalities by fluorescence in situ hybridization (FISH) in the clonal plasma cells, obtained either directly from the diagnostic SBP tissue or the corresponding bone marrow examination at the time of diagnosis, is associated with a shorter time to progression (TTP) to MM is unknown. This study evaluated all patients diagnosed with SBP at the Mayo Clinic from January 2012 to July 2022. The presence of del(17p), t(14;16), t(4;14), or +1q (gain or amplification) by FISH in clonal plasma cells was defined as HR. A total of 114 patients were included in this cohort, and baseline FISH was available for 55 patients (48%), of which 22 were classified as HR (40%). The median TTP to MM for patients with SBP and HR FISH was 8 months (95% confidence interval [CI], 6.3-26) compared with 42 months (95% CI, 25-not reached [NR]) in patients with SBP without HR FISH (P &lt; .001). In a multivariate analysis, only HR FISH was a significant predictor for shorter TTP to MM, independent of minimal marrow involvement and an abnormal serum free light chain ratio at diagnosis. Deletion (17p) and gain 1q abnormalities were the most common FISH abnormalities responsible for the short TTP to MM. Thus, assessing for HR FISH abnormalities in clonal plasma cells derived from either the diagnostic SBP tissue or the staging bone marrow examination of patients with newly diagnosed SBP is feasible and prognostic for a shorter TTP to MM.

Abstract Extramedullary multiple myeloma (EMM) can present either at initial diagnosis (de novo) or at disease relapse (secondary) and confers an aggressive clinical course. Limited data exist for choosing the optimal therapy for EMM and this remains an area of unmet clinical need. After excluding paraskeletal multiple myeloma and primary plasma cell leukemia, we identified 204 (68%) patients with secondary EMM and 95 (32%) with de novo EMM between January 01, 2000 and 31 December, 2021. The median overall survival (OS) was 0.7 (95% CI: 0.6–0.9) years for secondary EMM and 3.6 (95%CI: 2.4–5.6) years for de novo EMM. The median progression‐free survival (PFS) with initial therapy was 2.9 months (95% CI: 2.4–3.2 months) for secondary EMM and 12.9 months (95% CI: 6.7–18 months) for de novo EMM. Patients with secondary EMM treated with CAR‐T therapy ( n = 20) achieved a partial response (PR) or better in 75% with a median PFS of 4.9 months (3.1 months‐not reached; NR). Patients with EMM treated with bispecific antibodies ( n = 12) achieved a ≥ PR in 33%, with a median PFS of 2.9 months (95%CI: 2.2 months‐NR). In a matched cohort, multivariate logistic regression analysis demonstrated younger age at diagnosis, 1q duplication, and t (4;14) at diagnosis of MM to be independent predictors of development of secondary EMM. Presence of EMM was independently associated with inferior OS in the matched cohorts for both de novo (HR 2.9 [95% CI: 1.6–5.4], p = .0007) and secondary EMM (HR 1.5 [95% CI: 1.1–2], p = .001).

AbstractIn this phase 1/2 study, carfilzomib was added to high‐dose melphalan conditioning prior to autologous stem cell transplantation (ASCT) in patients with multiple myeloma that had been treated with ≤2 prior lines of therapy. Carfilzomib was escalated at doses of 27, 36, 45, and 56 mg/m2 on days −6, −5, −2, and −1 before ASCT in the phase 1 component of the study. In addition, all the patients received melphalan 100 mg/m2 on days −4 and −3. The primary endpoint of the phase 1 component was to identify the maximum tolerated dose, and the primary endpoint of the phase 2 component was the rates of complete response (≥CR) at 1 year after ASCT. The phase 1 dose escalation cohort included 14 patients, and 35 patients were included in the phase 2 cohort. The maximum tested dose was 56 mg/m2 (MTD). The median time from diagnosis to study enrollment was 5.8 (range 3.4–88.4) months, and 16% of patients had obtained a ≥CR prior to ASCT. The best response within 1 year after ASCT was a ≥ CR rate in 22% for the entire cohort, and 22% for patients treated at the MTD. The ≥VGPR rates improved from 41% before ASCT to 77% by 1 year after ASCT. One patient had a grade 3 renal adverse event, and renal function returned to baseline with supportive care. The rate of grade 3–4 cardiovascular toxicity was 16%. The addition of carfilzomib to melphalan conditioning was safe and resulted in deep responses after ASCT.

Abstract Patients with multiple myeloma (MM) who do not respond to initial therapy have worse outcomes than primary responders, and effective treatments are lacking in this population. However, the outcomes of primary refractory disease in the modern treatment era have not yet been studied. We reviewed patients with MM treated with triplet/quadruplet therapy at our institution to assess the incidence of primary refractory disease and the impact of salvage therapies in this population. We identified 1127 patients, of whom 1086 were evaluated for hematologic responses after 4 to 6 cycles. Of these, 93.3% (1013) had evidence of response, whereas 6.7% (73) had primary refractory disease. With a median overall survival (OS) of 51.3 months, patients with primary refractory disease had an increased risk of shorter survival in univariable and multivariable analyses (hazard ratio [HR], 3.5 [95% confidence interval (CI), 2.5-4.9]; HR, 4.3 [95% CI, 2.6-6.9], respectively). In the subgroup analysis of patients with primary refractory disease, those who received second-line autologous stem cell transplantation (ASCT) had increased second progression-free survival (20.9 vs 8.1 months; P &lt; .01) and second OS (74.7 vs 31.3 months; P = .02) compared with patients who did not. We conclude that early progression remains a significant factor for shorter OS in the current era, and salvage ASCT could be the most beneficial option for this population.