Impact of cytogenetic abnormalities on the risk of disease progression in solitary bone plasmacytomas.

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 < .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.

Daratumumab-lenalidomide and daratumumab-pomalidomide in relapsed lenalidomide-exposed or refractory multiple myeloma.

Daratumumab is an anti-CD38 mAb, used frequently in combination with lenalidomide and pomalidomide. No studies compared daratumumab plus lenalidomide and dexamethasone (DRd) to daratumumab plus pomalidomide and dexamethasone (DPd) in lenalidomide-exposed multiple myeloma. We identified 504 consecutive multiple myeloma patients who received daratumumab at Mayo Clinic between January 2015 and April 2019. We excluded patients who received daratumumab in the first line, received more than four lines of therapy prior to daratumumab use, did not receive lenalidomide prior to daratumumab, or had an unknown status of lenalidomide exposure, and patients who received daratumumab combinations other than DRd or DPd. We examined the impact of using DRd compared to DPd on progression-free survival (PFS) and overall survival (OS) in patients with relapsed/refractory multiple myeloma. Out of 504 patients, 162 received DRd or DPd and were included; 67 were lenalidomide-exposed and 95 were lenalidomide-refractory. DRd was used in 76 (47%) and DPd in 86 (53%) patients. In lenalidomide-exposed multiple myeloma, there was no difference in median PFS; 34.2 months [95% confidence interval (CI), 22.8-44.6] for DRd compared to 25.2 months (95% CI, 4.9-35.3) for DPd, P  = 0.2. In lenalidomide-refractory multiple myeloma, there was no difference in median PFS; 18.6 months (95% CI, 13-32) for DRd compared to 9 months (95% CI, 5.2-14.6) for DPd, P  = 0.09. No difference in median OS was observed in DRd compared to DPd. Our study shows combining daratumumab with lenalidomide in patients with prior lenalidomide use is a viable and effective treatment option.

Sarcopenia identified by computed tomography imaging using a deep learning-based segmentation approach impacts survival in patients with newly diagnosed multiple myeloma.

BACKGROUND: Sarcopenia increases with age and is associated with poor survival outcomes in patients with cancer. By using a deep learning-based segmentation approach, clinical computed tomography (CT) images of the abdomen of patients with newly diagnosed multiple myeloma (NDMM) were reviewed to determine whether the presence of sarcopenia had any prognostic value. METHODS: Sarcopenia was detected by accurate segmentation and measurement of the skeletal muscle components present at the level of the L3 vertebrae. These skeletal muscle measurements were further normalized by the height of the patient to obtain the skeletal muscle index for each patient to classify them as sarcopenic or not. RESULTS: The study cohort consisted of 322 patients of which 67 (28%) were categorized as having high risk (HR) fluorescence in situ hybridization (FISH) cytogenetics. A total of 171 (53%) patients were sarcopenic based on their peri-diagnosis standard-dose CT scan. The median overall survival (OS) and 2-year mortality rate for sarcopenic patients was 44 months and 40% compared to 90 months and 18% for those not sarcopenic, respectively (p < .0001 for both comparisons). In a multivariable model, the adverse prognostic impact of sarcopenia was independent of International Staging System stage, age, and HR FISH cytogenetics. CONCLUSIONS: Sarcopenia identified by a machine learning-based convolutional neural network algorithm significantly affects OS in patients with NDMM. Future studies using this machine learning-based methodology of assessing sarcopenia in larger prospective clinical trials are required to validate these findings.

Thrombosis in multiple myeloma: Risk estimation by induction regimen and association with overall survival.

Lenalidomide-containing (R) triplet and quadruplet regimens are the standard of care for multiple myeloma (MM) and have been shown to increase the risk of thrombosis. The association between thromboembolism (TE) and survival in the novel multidrug era is not yet delineated. In this study, we evaluated the incidence of TE during the first year of MM diagnosis, its association with the type of induction regimen, and its impact on overall survival. We studied 672 newly diagnosed MM (NDMM) patients who received a triplet or quadruplet lenalidomide-based induction at the Mayo Clinic, Rochester. TE was diagnosed in 83 patients (12.4%). Of these, 56 (8.3%) had a deep venous thrombosis (DVT), 23 (3.4%) had a pulmonary embolism (PE) with or without the DVT, and 4 (0.6%) patients had a stroke. Carfilzomib-Rd (KRd) had the highest risk of TE (21.1%, 18/85), followed by quadruplets (11.1%, 5/45), bortezomib-Rd (9.6%, 51/531), and 0/11 (0%), treated with other lenalidomide-containing regimens. The difference in TE risk between KRd and the other regimens was statistically significant (OR = 2.6, p < .01). Nine patients developed a TE before being exposed to any treatment. Survival was significantly lower among patients that developed a TE (66 vs. 133 months, p < .01). The association of TE with reduced survival demonstrated in univariate analysis (HR = 2.2, 95% CI = 1.6-3.3) was maintained in the multivariable analysis adjusted for high-risk interphase fluorescence in situ hybridization (FISH), sex, age, receipt of an upfront transplant, the response at induction, and the International Staging System (ISS) (HR = 2.61, CI = 1.74-3.9). We conclude that TE is an important aspect of MM management, and effective management is especially relevant in the novel treatment era.

A phase 1/2 of carfilzomib and melphalan conditioning for autologous stem cell transplantation for multiple myeloma (CARAMEL).

In 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.

Natural history, predictors of development of extramedullary disease, and treatment outcomes for patients with extramedullary multiple myeloma.

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).

Risk factors for severe infection and mortality In patients with COVID-19 in patients with multiple myeloma and AL amyloidosis.

Patients with multiple myeloma (MM) have a lower efficacy from COVID-19 vaccination and a high rate of mortality from COVID-19 in hospitalized patients. However, the overall rate and severity of COVID-19 infection in all settings (including non-hospitalized patients) and the independent impact of plasma cell-directed therapies on outcomes needs further study. We reviewed the medical records of 9225 patients with MM or AL amyloidosis (AL) seen at Mayo Clinic Rochester, Arizona, and Florida between 12/01/2019 and 8/31/2021 and identified 187 patients with a COVID-19 infection (n = 174 MM, n = 13 AL). The infection rate in our cohort was relatively low at 2% but one-fourth of the COVID-19 infections were severe. Nineteen (10%) patients required intensive care unit (ICU) admission and 5 (3%) patients required mechanical ventilation. The mortality rate among hospitalized patients with COVID-19 was 22% (16/72 patients). Among patients that were fully vaccinated at the time of infection (n = 12), two (17%) developed severe COVID-19 infection, without any COVID-related death. On multivariable analysis, treatment with CD38 antibody within 6 months of COVID-19 infection [Risk ratio (RR) 3.6 (95% CI: 1.2, 10.5), p = .02], cardiac [RR 4.1 (95% CI: 1.3, 12.4), p = .014] or pulmonary comorbidities [RR 3.6 (95% CI 1.1, 11.6); p = .029] were independent predictors for ICU admission. Cardiac comorbidity [RR 2.6 (95% CI: 1.1, 6.5), p = .038] was an independent predictor of mortality whereas MM/AL in remission was associated with lower mortality [RR 0.4 (95% CI: 0.2-0.8); p = .008].

Impact of achieving a complete response to initial therapy of multiple myeloma and predictors of subsequent outcome.

Achievement of a complete response (CR) in multiple myeloma (MM) correlates with improvement in survival outcomes; however, its impact on prognostic variables at baseline outside of clinical trial settings is not well described. We sought to determine the impact of achieving a CR within 2 years from diagnosis, its effect on the prognostic value of fluorescence in situ hybridization (FISH) and International Staging System (ISS) risk, and examined additional predictors of outcome among those achieving a CR in a routine clinical setting. We evaluated 1869 newly diagnosed MM patients who had ≥ 2 monoclonal protein immunofixation studies in the serum and urine available within 24 months from diagnosis, categorizing those with ≥ 2 negative serum and urine immunofixations as achieving CR. With a landmark at 24 months, median progression-free survival (PFS) for CR versus non-CR patients was 29.8 versus 20.9 months (p ≤ .0002); median overall survival (OS) was 104 versus 70 months (p < .0001). The impact of achieving a CR was retained after adjusting for FISH, ISS, sex, transplant status, and involved heavy chain. Baseline FISH and ISS stage were not associated with PFS or OS among patients achieving a CR. The following variables were found as predictors of inferior OS within the CR cohort: age > 75 years, male gender, hypoalbuminemia, and non-immunoglobulin G involved heavy chain. Our study confirms that achievement of CR within 2 years from diagnosis is associated with improvement in survival outcomes and neutralization of the impact of FISH and ISS risk, thereby confirming observations from the clinical trial setting among a clinical practice cohort.

Characteristics and risk factors for thrombosis in POEMS syndrome: A retrospective evaluation of 230 patients.

Thromboses are prevalent in POEMS syndrome, but few risk factors for POEMS-associated thrombosis have been identified. The objective of this study is to identify novel risk factors for POEMS-associated thrombosis. In this retrospective cohort of 230 POEMS patients, 27% developed thrombosis. Arterial events were slightly more common than venous. Stroke accounted for 26% of all thromboses and 53% of arterial events. There were differences in baseline features between the thrombosis group and the no thrombosis group, and these were driven by patients with arterial thrombosis. Risk factors for arterial thrombosis included thrombocytosis, elevated hemoglobin/hematocrit, extravascular volume overload, and splenomegaly. Hyperprolactinemia appeared to be a risk factor for venous thrombosis. The risk of thrombosis was most striking among men with elevated hemoglobin (32% vs. 5%, p < .001) and hematocrit (42% vs. 5%, p < .001) compared to men without. Most thromboses occurred prior to POEMS directed therapy, and most that occurred during therapy happened within 3 months of diagnosis. Twenty-one percent of patients with thrombosis had recurrence. In recognition of high overall rates of thrombosis in this population, all patients with POEMS syndrome should receive prophylactic antiplatelet therapy, and clinicians should consider anticoagulation in patients with risk factors for POEMS-associated thrombosis.

Multicentric Castleman disease: A single center experience of treatment with a focus on autologous stem cell transplantation.

Castleman disease (CD) is a rare lymphoproliferative disease characterized by diverse clinical and pathologic features. Due to its rarity, there are limited studies comparing currently available therapies. The role of autologous stem cell transplantation (ASCT) in CD has not yet been established. In this paper, we describe the clinical characteristics, treatment choices, and outcomes in 34 Mayo Clinic patients diagnosed with multicentric CD from July 1, 2003 to April 30, 2018. Eighteen patients (53%) also met the criteria for POEMS, including 14 with the osteosclerotic variant. The first-line treatments included: steroid monotherapy (4), cytotoxic chemotherapy (6), rituximab alone (8) or with chemotherapy (2), anti-IL6 treatment (3), and ASCT (10). The median follow-up was 4.8 (range: 0.1-15.2) years. The 5- and 10-year overall survival rates were 84% and 71%, respectively. Sixteen patients received high-dose chemotherapy followed by ASCT during their disease course. Among those, 14 had multicentric CD associated with POEMS. There were no transplant-related deaths. All patients had at least a partial response to ASCT, most of whom achieved a complete response. The favorable outcomes seen with ASCT in this cohort suggest that transplantation may have a role in multicentric CD, particularly for patients with multicentric CD associated with POEMS.

Prognostic significance of acquired 1q22 gain in multiple myeloma.

Gain of 1q22 at diagnosis portends poorer outcomes in multiple myeloma (MM), but the prognostic significance of acquired 1q22 gain is unknown. We identified 63 MM patients seen at Mayo Clinic from 1/2004 to 12/2019 without 1q22 gain at diagnosis who acquired it during follow up and compared them to 63 control patients who did not acquire 1q22 gain with similar follow up. We also compared outcomes in the acquired 1q22 gain group with outcomes in 126 patients with 1q22 gain present at diagnosis. The incidence of acquired 1q22 gain was 6.1% (median follow-up 6.8 years); median time to acquisition was 5.0 years (range: 0.7-11.5 years). Abnormalities on baseline fluorescence in situ hybridization (FISH) included trisomies (54%) and monosomy 13 (39%); 16 (25%) had high-risk (HR) translocations or del(17p). Median progression-free survival with front line therapy was 29.5 months in patients with acquired 1q22 gain, versus 31.4 months in control patients (p = .34) and 31.2 months in patients with de novo 1q22 gain (p = .04). Median overall survival (OS) from diagnosis was 10.9 years in patients with acquired 1q22 gain, versus 13.0 years in control patients (p = .03) and 6.3 years in patients with de novo 1q22 gain (p = .01). Presence of HR FISH at baseline increased risk of 1q22 gain acquisition. We demonstrate that acquisition of 1q22 gain is a significant molecular event in MM, associated with reduced OS. Among HR patients for whom this clonal evolution is determined, a risk-adapted approach and/or clinical trial should be considered.

Humoral and cellular immune responses to recombinant herpes zoster vaccine in patients with chronic lymphocytic leukemia and monoclonal B cell lymphocytosis.

Monoclonal B-cell lymphocytosis (MBL) and chronic lymphocytic leukemia (CLL) are clonal B-cell disorders associated with an increased risk of infections and impaired vaccination responses. We investigated the immunogenicity of recombinant zoster vaccine (RZV) in these patients. Individuals with MBL/untreated CLL and Bruton tyrosine kinase inhibitor (BTKi)-treated CLL patients were given two doses of RZV separated by 2 months. Responses assessed at 3 and 12 months from the first dose of RZV by an anti-glycoprotein E ELISA antibody assay and by dual-color Interferon-γ and Interleukin-2FLUOROSPOT assays were compared to historic controls matched by age and sex. About 62 patients (37 MBL/untreated CLL and 25 BTKi-treated CLL) were enrolled with a median age of 68 years at vaccination. An antibody response at 3 months was seen in 45% of participants, which was significantly lower compared to historic controls (63%, p = .03). The antibody response did not significantly differ between MBL/untreated CLL and BTKi-treated CLL (51% vs. 36%, respectively, p = .23). The CD4+ T-cell response to vaccination was significantly lower in study participants compared to controls (54% vs. 96%, p < .001), mainly due to lower responses among BTKi-treated patients compared to untreated MBL/CLL (32% vs. 73%, p = .008). Overall, only 29% of participants achieved combined antibody and cellular responses to RZV. Among participants with response assessment at 12 months (n = 47), 24% had antibody titers below the response threshold. Hypogammaglobulinemia and BTKi therapy were associated with reduced T-cell responses in a univariate analysis. Strategies to improve vaccine response to RZV among MBL/CLL patients are needed.

Characterization and prognostic implication of delayed complete response in AL amyloidosis.

INTRODUCTION: Little is known on continued response following completion of therapy in light chain (AL) amyloidosis. METHODS: We studied 373 AL amyloidosis patients who achieved complete response (CR) or very good partial response (VGPR) to first-line therapy. RESULTS: By end of therapy (EOT), 46% of patients achieved a CR and 54% a VGPR. With no further therapy, 17.5% of patients were upstaged from VGPR to CR (delayed CR), with a median of 9 months. Compared with CR and VGPR at EOT, patients with a delayed CR were characterized by higher proportion of t(11;14) and lower rate of trisomies. Autologous stem cell transplant was more frequent in the delayed CR group. Patients with a delayed CR were characterized by minimal residual disease negativity and organ response rates similar to patients with CR at EOT and higher than patients achieving VGPR at EOT. Patients with a delayed CR had a longer PFS/OS compared to patients with CR or VGPR by EOT (median PFS 149 vs 92 vs 52 months, P < .001; 10-year OS 87% vs 71% vs 56%, P < .001). CONCLUSIONS: This study characterizes delayed CR in AL amyloidosis, highlights its prognostic impact which is at least similar to those who achieved CR at EOT, and underlines another aspect of response monitoring.

Outcomes with different administration schedules of bortezomib in bortezomib, lenalidomide and dexamethasone (VRd) as first-line therapy in multiple myeloma.

Induction therapy for multiple myeloma with bortezomib (Velcade), lenalidomide (Revlimid), and dexamethasone (d) (VRd) was traditionally administered as bortezomib given twice weekly on a 3 week cycle. A modified schedule of weekly bortezomib has been adopted over time to decrease treatment burden for patients and reduce treatment-emergent neuropathy. This study evaluates the response rates and outcomes with different schedules of bortezomib in VRd administered for first-line treatment for patients with newly diagnosed MM (NDMM). We retrospectively analyzed patients treated with upfront VRd from June 30th 2008 to December 31st 2018, for variations of bortezomib administration. Five hundred and fifty-five (555) NDMM patients met inclusion criteria; median age 63 years and 61% men. Bortezomib was administered twice weekly every 21 days in 43%, once weekly every 21 days in 41% and once weekly every 28 days in 16%. Though peripheral sensory neuropathy was more frequent with twice weekly dosing (P = .002), this group achieved shorter time to best response (P = .01). Weekly every 21-day treatment saw higher VGPR or better rates (P = .02). However, with median follow up time of 37 months (IQR 22-56), we found no difference in PFS or OS among the groups. While small differences in response rates were found among the varying administration schedules of bortezomib administration, there was no significant effect on PFS or OS. Given that VRd remains a first line standard of care option for newly diagnosed MM, in the absence of a large trial comparing bortezomib dosing schedule modifications, these results are helpful in supporting current practices of once weekly administration.

Venetoclax for the treatment of multiple myeloma: Outcomes outside of clinical trials.

Multiple myeloma (MM) remains an incurable disease despite incorporation of novel agents. Venetoclax, a B-cell lymphoma 2 (BCL-2) inhibitor is approved for some hematologic malignancies but not yet for MM, although clinical trials have shown efficacy in patients with MM, particularly those harboring t(11;14). We reviewed the medical records of relapsed and/or refractory MM patients to study the efficacy and safety of venetoclax used outside of clinical trials at Mayo Clinic between December, 2016 and March, 2019. The data cut-off date was August 06, 2020. We identified 56 patients of whom 42 (75%) harbored t(11;14). The median number of prior therapies was six (range 1-15) and 14% of patients had received ≥10 prior lines of therapy. Fifty-three (95%) patients were refractory to an immunomodulatory drug and proteasome inhibitor. Venetoclax was used as monotherapy or doublet, in combination with dexamethasone in 55% (n = 31) and a triplet or quadruplet in 45% of patients. No patient experienced tumor lysis syndrome. Overall response rate in 52 evaluable patients was 44%. The median time to best response was 2 months and median duration of response was 13.6 months. The median PFS for the entire cohort was 5.8 (95% CI 4.9-10.3) months and median OS was 28.4 (95% CI 14.6-not reached) months. The presence of t(11;14) was associated with improved PFS (median 9.7 months vs. 4.2 months, p = 0.019) and OS (median not reached vs. 10.8 9 months, p = 0.015). Venetoclax demonstrates encouraging activity in heavily-treated patients with relapsed/refractory MM, particularly the t(11;14) patient-population.

Comparison of the current renal staging, progression and response criteria to predict renal survival in AL amyloidosis using a Mayo cohort.

Three sets of criteria (International Society of Amyloidosis [ISA], Palladini and Kastritis) were independently developed for staging, progression and response criteria to predict renal survival in patients with AL amyloidosis. We evaluated these criteria using a cohort of 495 newly diagnosed AL amyloidosis patients with renal involvement using time to event competing risk analysis at baseline, 3, 6 and 12 months after treatment. Only Palladini and Kastritis had a staging system and both predicted a higher risk of end stage renal disease (ESRD) in the stage III vs stage I patients but only the Palladini model was predictive for stage II patients. At 3 months, risk of ESRD was significantly higher for Palladini and ISA renal progression (hazard ratio [HR] 2.8 [95% CI: 1.5-5.3, p = .001] and 2.5 [CI: 1.4-4.6, p = .004, respectively]), but renal response was not significantly protective; conversely, the risk of ESRD was not significantly higher for the Kastritis renal progression, but was significantly protective for the Kastritis renal responders (HR 0.38 [95% CI: 0.17-0.84], p = .017). Both progression and response with ISA, Palladini and Kastritis criteria were predictive of ESRD at 6 months and 12 months. While the Palladini staging criteria at baseline, and the ISA and Palladini criteria for progression at 3 months performed better than the Kastritis criteria at baseline and 3 months post-treatment, the Kastritis criteria performed better for response 3 months after treatment. All three sets of criteria performed well at and after 6 months post-treatment. These differences are important when choosing endpoints for clinical trials.

Prognostic Role of Beta-2 Microglobulin in Patients with Light Chain Amyloidosis Treated with Autologous Stem Cell Transplantation.

The prognostic impact of increased beta-2 microglobulin (B2M) in patients with light chain (AL) amyloidosis undergoing autologous stem cell transplantation (ASCT) is unknown. The Mayo 2012 stage and increased bone marrow plasma cell (BMPC) percentage are known predictors for survival. Increased B2M is predictive of survival in patients with multiple myeloma. We evaluated the prognostic role of B2M in patients with newly diagnosed AL undergoing ASCT. We retrospectively reviewed patients with a diagnosis of AL amyloidosis who were treated with ASCT between July 1996 and September 2017. Patients with a creatinine level >1.2 mg/dL were excluded, because that affects B2M levels. The receiver operator characteristic curve was used to determine the best cutoff for B2M before ASCT in predicting survival, which was 2.5 µg/mL, which was also the upper limit of normal in our laboratory. Baseline characteristics were compared between patients with B2M >2.5 µg/mL and ≤2.5 µg/mL. Progression-free survival (PFS) was defined as the time from ASCT to relapse or death, whichever occurred first. Overall survival (OS) was calculated from the time of ASCT to death of any cause. Univariate and multivariate analyses were done for OS. Five hundred and ten patients were identified, 222 of whom (44%) had a B2M >2.5 µg/mL. These patients were more likely to be older (median age, 61 versus 57 years; P = .0002), to have Mayo 2012 stage III/IV disease (33% versus 8%; P < .0001), to have more than 2 organs involved (25% versus 14%; P = .001), and to have ≥10% BMPCs (56% versus 40%; P = .0002) compared with patients with B2M ≤2.5 µg/mL. The median PFS and OS were shorter in patients with B2M >2.5 µg/mL (median PFS, 64 months versus 80 months [P = .03]; median OS, 104.9 months versus 175.5 months [P < .0001]). On univariate analysis, predictors for OS included age >60 years (hazard ratio [HR], 1.61; P = .001), Mayo 2012 stage III/IV (HR, 3.36; P < .0001), more than 2 organs involved (HR, 1.36; P = .07), ≥10% BMPCs (HR, 1.5; P = .005), melphalan conditioning with 200 mg/m2 (HR, .29; P < .0001), B2M >2.5 µg/mL (HR, 1.82; P < .0001), and transplantation during or after 2010 (HR, .4; P = .0006). On multivariate analysis, only Mayo 2012 stage III/IV (HR, 1.89; P = .005), melphalan conditioning with 200 mg/m2 (HR, .39; P < .0001), B2M >2.5 µg/mL (HR, 1.84; P = .003), and transplantation performed during or after 2010 (HR, .58; P = .03) remained independent predictors of OS. Our findings identify B2M >2.5 µg/dL before ASCT as an independent predictor for OS in patients with AL amyloidosis and normal kidney function and should be routinely measured.

Impact of minimal residual negativity using next generation flow cytometry on outcomes in light chain amyloidosis.

We evaluated bone marrow minimal residual disease (MRD) negativity in 44 patients with light chain (AL) amyloidosis using next generation flow cytometry (sensitivity ≥1 × 10-5 ; median events analyzed: 8.7 million, range: 4.8 to 9.7 million). All patients underwent MRD testing in 2 years from start of therapy (median: 7 months). The overall MRD negative rate was 64% (n = 28). The MRD-negative rate after one-line of therapy was 71% (20/28). And, MRD negative rates were higher with stem-cell transplant as first-line therapy (86%, 18/21) vs chemotherapy alone as first-line treatment (29%, 2/7), P = .005. The MRD negative rate amongst patients in complete response was 75% (15/20), and in very good partial response, 50% (11/22). There were two patients in partial response/rising light chains (with renal dysfunction) who were MRD negative. There were no differences in baseline characteristics of MRD negative vs MRD positive patients, except younger age amongst MRD-negative patients. Patients with MRD negativity were more likely to have achieved cardiac response at the time of MRD assessment, 67% (8/12) vs 22% (2/7), P = .04. Renal response rates were similar in both groups. Progression free survival was assessed in the 42 patients achieving CR or VGPR. After median follow-up of 14 months, the estimated 1-year progression free survival in MRD negative vs MRD positive patients was 100% (26 patients, 0 events) vs 64% (16 patients, five events), P = .006, respectively. MRD assessment should be explored as a surrogate endpoint in clinical trials and MRD risk-adapted trials may help optimize treatment in AL amyloidosis.

Refining amyloid complete hematological response: Quantitative serum free light chains superior to ratio.

Response assessment in light chain (AL) amyloidosis is based on serum and urine monoclonal protein studies. Newly diagnosed patients (n = 373) who achieved very good partial response or complete response (CR) to first line therapy were assessed for the survival impact of each of the monoclonal protein studies. At end of therapy (EOT), negative serum/urine immunofixation (IFE) was achieved in 61% of patients, 72% achieved normal serum free light chain ratio (sFLCR), and the median involved free light chain (iFLC) and difference between involved to uninvolved light chain (dFLC) were 17 mg/L and 5 mg/L, respectively. Overall, 46% of patients achieved a CR at EOT. At EOT, iFLC ≤20 mg/L and dFLC ≤10 mg/L were additive in survival discrimination to negative serum/urine IFE and were independent predictors of overall survival. In contrast, normalization of sFLCR did not add survival discrimination to serum/urine IFE and was not independent predictor of survival. We propose a new definition for hematological CR to include serum/urine IFE negativity plus iFLC ≤20 mg/L or dFLC ≤10 mg/L, instead of the current definition of serum/urine IFE negativity and normal sFLCR. Complete response using dFLC ≤10 mg/L had the best performance in those with significant renal dysfunction and by light chain isotype, making it the preferred partner to IFE. Validation of these results in a multicenter cohort is warranted.

Utilizing multiparametric flow cytometry in the diagnosis of patients with primary plasma cell leukemia.

The diagnosis of primary plasma cell leukemia (pPCL) has been made by quantifying circulating plasma cells (cPCs) morphologically on a peripheral blood (PB) smear. However, this technique is not sufficiently sensitive. Multiparametric flow cytometry (MFC) provides a readily available and highly sensitive method to identify and quantify cPCs that could complement PB smear assessment. However, an optimal quantitative cutoff for cPCs by MFC to identify pPCL has not been established. Thus, a total of 591 patients newly diagnosed multiple myeloma (NDMM) patients who had their PB samples evaluated morphologically by PB smear, and immunophenotypically by MFC prior to beginning therapy were evaluated. The presence of ≥200 cPCs/µL by MFC (N = 25 or 5% of the total population) was chosen to identify patients with ≥5% cPCs by PB smear with a specificity of 99% and a sensitivity of 77%. For patients with ≥200 cPCs/µL by MFC compared to the remainder of the cohort, the median Time to next therapy (TTNT) was 18 vs 30 months and the median OS was 38 vs 70 months respectively. Thus, MFC assessment of PB can be utilized in conjunction with the morphological assessment of a PB smear to aid in improving the identification of pPCL among NDMM patients.