The Latin American experience in POEMS syndrome. A study of the GELAMM (Grupo de Estudios Latinoamericanos de Mieloma Múltiple).

INTRODUCTION: POEMS syndrome is a rare paraneoplastic syndrome caused by an underlying plasma cell disorder. The acronym refers to the following features: polyradiculoneuropathy, organomegaly, endocrinopathy, monoclonal paraproteinemia, and skin changes. METHODS: The study was conducted at 24 hematological centers across 8 Latin-American countries. The study included a total of 46 patients (median age was 52 years (IQR: 42 - 61.5), 30 males and 16 females) fulfilling the POEMS syndrome criteria diagnosed over a period of 12 years (January 1, 2011, through July 31, 2023). Epidemiological and clinical data were collected in an ad-hoc database sent to the members of GELAMM, as well as the Kolmogorov-Smirnov test and Kaplan-Meier estimates. RESULTS: All patients had polyneuropathy; 89% had monoclonal gammopathy, 33% had sclerotic bone lesions. Only ten patients underwent vascular endothelial growth factor (VEGF) testing in plasma samples. The paraproteinemia was IgG λ in 32% and IgA λ in 30%. 59% patients presented with cutaneous changes, mainly hyperpigmentation, 54% had organomegaly, and 74% endocrinopathy. The median interval from symptom onset to diagnosis was 7.7 months (IQR: 4.0 - 12.6). 69% of patients received a single line of treatment. The median follow-up period was 25 months (IQR: 9.37 - 52.0) and the 2-year overall survival rate was 100%. All patients who underwent transplantation (43%) are alive, with a median follow-up of 45.62 months (IQR: 15.46 - 70). CONCLUSION: This study investigates POEMS syndrome in Latin America and presents an initial overview of the disease in the region. VEGF usage is recommended for accurate diagnosis, but only 7 hematology centers in the region used it. Survival rate in Latin America is comparable with those observed internationally.

Herpesviral encephalitis associated with bortezomib use in a patient with multiple myeloma and associated light-chain amyloidosis.

INTRODUCTION: Bortezomib is proteasome inhibitor used in multiple myeloma treatment. The reactivation of herpes simplex virus (HSV) and varicella-zoster virus (VZV) during bortezomib-based therapy is a well-known adverse event. Antiviral prophylaxis is mandatory. Nevertheless, reports of herpesviral encephalitis are scarce. CASE REPORT: A 57-year-old multiple myeloma patient who during CyBorD protocol (Bortezomib, cyclophosphamide, and dexamethasone), after a transient suspension of antiviral prophylaxis presented progressive headaches unresponsive to conventional analgesics, asthenia, fever, episodic visual hallucinations, and vesicular lesions in the right supraorbital and frontal region. Herpetic encephalitis was diagnosed after detecting herpes zoster in cerebrospinal fluid. MANAGEMENT & OUTCOME: The patient was treated with acyclovir 500mg every 6 hours for 21 days, and subsequent valacyclovir prophylaxis achieving an excellent clinical evolution. Anti-myeloma treatment was changed to lenalidomide and dexamethasone achieving a durable complete response. Herpesviral encephalitis is a rare but severe complication associated with the use of Bortezomib, especially when patients did not receive acyclovir prophylaxis. However, a rapid detection based on the clinical suspicion, and the prompt start of treatment, may lead to overcome this adverse event.

[18F-fluorodesoxyglucose positron emission tomography/computed tomography in extramedullary multiple myeloma]. / Aportes de la tomografía por emisión de positrones con 18F-fluorodesoxiglucosa/tomografía computada en el diagnóstico de compromiso extramedular por mieloma múltiple en Uruguay.

BACKGROUND: 18F-fluorodesoxyglucose positron emission tomography/ computed tomography (PET-CT) has a high sensitivity and specificity to detect medullary and extramedullary lesions in multiple myeloma (MM). AIM: To describe the findings of PET-CT in extramedullary multiple myeloma (EMM) at diagnosis and at relapse, and correlate its results with clinical variables, response to treatment and survival. MATERIALS AND METHODS: Review of medical records and PET-CT reports of 39 patients with multiple myeloma (MM) who had at least one PET-CT study, treated between January 1, 2015, and January 1, 2019 at a clinical hospital. RESULTS: The Standard Uptake Values for each hypermetabolic lesion were not described in PET-CT reports. Fifteen patients had an EMM and in eight, without a previous clinical suspicion, PET-TC lead to the diagnosis. The mortality rate in the 39 patients with MM was 46%. Sixty seven percent of deaths occurred in patients with EMM. CONCLUSIONS: PET-TC was useful to diagnose EMM. However, a standardization in PETCT reports would be required to unify criteria. As previously reported, EMM had a greater aggressiveness and lower survival.

Treatment of relapsed and refractory multiple myeloma: recommendations from the International Myeloma Working Group.

This Policy Review presents the International Myeloma Working Group's clinical practice recommendations for the treatment of relapsed and refractory multiple myeloma. Based on the results of phase 2 and phase 3 trials, these recommendations are proposed for the treatment of patients with relapsed and refractory disease who have received one previous line of therapy, and for patients with relapsed and refractory multiple myeloma who have received two or more previous lines of therapy. These recommendations integrate the issue of drug access in both low-income and middle-income countries and in high-income countries to help guide real-world practice and thus improve patient outcomes.

Comparison of two different anti-infectious approaches after high-dose chemotherapy and autologous stem cell transplantation for hematologic malignancies in a 12-year period in British Hospital, Uruguay.

Autologous stem cell transplant (ASCT) is a widely used and safe procedure to treat mostly hematologic diseases. These patients are at risk of infectious complications, which represents a major cause of morbidity and it is the second cause of mortality. This retrospective 12-year analysis of the incidence, type, and severity of infections in 266 consecutive unselected ASCT patients at our institution provides novel information addressing this issue. We included 266 ASCT procedures. Patients included in the 2006-2013 period are referred to as group 1 (ciprofloxacin prophylaxis and ceftazidime-amikacin as empirical antibiotics), and those in the 2013-2017 period are group 2 (levofloxacin prophylaxis and meropenem as empirical antibiotics). The incidence of febrile neutropenia was 72% in group 1 and 86.2% in group 2 (p = 0.004). The majority of infectious episodes were associated with fever of unknown origin: 55% in group 1 and 59% in group 2. Febrile of unknown origin episodes were 82.6% in group 1 and 80% in group 2. Significant differences between both groups were found in age, hypogammaglobulinemia, and advanced disease at ASCT. No differences were found between groups regarding the most common agent documented in positive blood cultures (Gram+ were 66.6% in group 1 and 69% in group 2 (p = 0.68)). Mortality within 100 days of transplant was low, 1.87%. Regardless of the prophylactic regimen used, most patients experience febrile episodes in the ASCT setting, fever of unknown origin is the most common infection complication, and Gram+ agents are prevalent in both groups. Mortality rates were low. According to our results, ASCT is a safe procedure and there is no clear benefit in favor of levofloxacin versus ciprofloxacin prophylaxis. Both anti-infectious approaches are acceptable, yielding similar outcomes.

Significant differences in access to tests and treatments for multiple myeloma between public and private systems in Latin America. Results of a Latin American survey. GELAMM (Grupo de Estudio Latino Americano de Mieloma Múltiple).

The incidence of multiple myeloma (MM) has increased in the last 20 years, particularly in middle and low-middle income countries. Access to diagnostic and prognostic tests and the availability of effective care is highly variable globally. Latin America represents 10% of the world population, distributed in countries of varied size, population, and socio-economic development. In the last decade, great improvements have been made in the diagnosis and treatment of MM. Applying these advances in real life is a challenge in our region. Local data regarding MM standards of care and outcomes are limited. A survey was carried out among hematologists from 15 Latin American countries to describe access to MM diagnostic and prognostic tests and the availability of effective care options. This study provides real-world data for MM in our region, highlighting striking differences between public and private access to essential analyses and therapeutic options.

Epidemiological and clinical characteristics and outcome of monoclonal gammopathy of renal significance-related lesions in Latin America.

BACKGROUND: Monoclonal gammopathy of renal significance (MGRS)-related lesions are infrequent entities. There are no publications on these disorders in Latin America (LA). The aim of this study was to describe epidemiological and clinical characteristics of these patients in LA. METHODS: We performed a multicentre retrospective study. Patients with diagnosis of MGRS between 2012 and 2018 were included. Epidemiological and clinical data were collected from clinical records. RESULTS: Twenty-seven patients from Chile, Argentina, Ecuador and Uruguay were included. Half debuted with a nephrotic syndrome, and 32% required dialysis. Proliferative glomerulonephritis with monoclonal immunoglobulin deposits was found in 33%, amyloidosis in 26% and monoclonal immunoglobulin deposition disease also in 26%. The immunoglobulin most frequently found in renal biopsies was IgG kappa. In 67% a paraprotein was found. Twenty patients received an anti-plasma cell regimen, and 3 a rituximab-based regimen (IgM-MGRS). Renal response (RR) was achieved in 56%. Early treatment (≤3 months) was associated with higher RR (75% vs 43%). Three patients relapsed within 21.5 months, and 3 progressed: 1 to multiple myeloma, 1 to systemic amyloidosis and another to systemic light-chain deposition disease. Two patients died, both due to infection during induction treatment. CONCLUSION: There was a higher than expected frequency of patients requiring dialysis. The most common MGRS-related lesion was PGNMD. Early treatment was associated with better response. As a rare disease, increasing awareness and promoting early diagnosis are necessary in LA to improve outcomes. SUMMARY AT A GLANCE A collection of 27 cases of MGRS from Latin America with information on epidemiology, clinical characteristics, treatment and outcome of patients diagnosed of MGRS-related renal lesions.

International myeloma working group consensus recommendations on imaging in monoclonal plasma cell disorders.

Recent advances in the treatment of multiple myeloma have increased the need for accurate diagnosis of the disease. The detection of bone and bone marrow lesions is crucial in the investigation of multiple myeloma and often dictates the decision to start treatment. Furthermore, detection of minimal residual disease is important for prognosis determination and treatment planning, and it has underscored an unmet need for sensitive imaging methods that accurately assess patient response to multiple myeloma treatment. Low-dose whole-body CT has increased sensitivity compared with conventional skeletal survey in the detection of bone disease, which can reveal information leading to changes in therapy and disease management that could prevent or delay the onset of clinically significant morbidity and mortality as a result of skeletal-related events. Given the multiple options available for the detection of bone and bone marrow lesions, ranging from conventional skeletal survey to whole-body CT, PET/CT, and MRI, the International Myeloma Working Group decided to establish guidelines on optimal use of imaging methods at different disease stages. These recommendations on imaging within and outside of clinical trials will help standardise imaging for monoclonal plasma cell disorders worldwide to allow the comparison of results and the unification of treatment approaches for multiple myeloma.

Technetium-99m- or Cy7-Labeled Rituximab as an Imaging Agent for Non-Hodgkin Lymphoma.

INTRODUCTION: Rituximab was the first monoclonal antibody approved for the treatment of B-cell non-Hodgkin lymphoma (NHL) expressing CD20 antigen. This antibody has also the potential to be used as a specific fluorescent and radiolabel agent for targeting NHL. OBJECTIVE: To radiolabel rituximab with technetium-99m (99mTc) or Cy7 and evaluate both probes as potential imaging agents for NHL. METHODS: Rituximab was derivatized with the trifluoroacetyl hydrazino protected form of succinimidyl ester of HYNIC and radiolabeled with 99mTc. Radiochemical stability and in vitro cell assays were evaluated. Biodistribution and single-photon emission computed tomography/computed tomography (SPECT/CT) were performed. Raji cells were transfected with luciferase for bioluminescent NHL imaging up to 21 days. Rituximab was labeled with Cy7 for in vivo noninvasive fluorescence imaging up to 96 h. RESULTS: Radiolabeling was carried out in a fast, reproducible, easy, and stable way with high radiochemical purity and did not interfere with epitope recognition. Biodistribution and SPECT/CT studies showed high liver and discrete tumor uptake. Bioluminescence and fluorescence studies helped us evaluate rituximab-Cy7 in Raji subcutaneous engraftment in BALB/c nude mice. CONCLUSIONS: Our results support the potential use of rituximab labeled either with 99mTc or Cy7 as a molecular imaging tool for staging, restaging, and guiding surgical excision of tumors, which merits further evaluation.

Development and Evaluation of a Hematology-Oriented Clinical Research Training Program in Latin America.

The objectives of the study were to describe the development of a patient-oriented clinical research training program in a low- or middle-income country (LMIC) setting, to describe perceived benefits of the program and barriers to application, and to make recommendations for future training programs. The program was developed by the American Society of Hematology in collaboration with Latin American stakeholders and clinical researchers. Session types were didactic, small group, and one-on-one faculty/participant dyad formats. Outcomes were assessed by quantitative surveys of trainees and qualitative feedback from both trainees and faculty members. The program is an annual 2-day course specifically for Latin American hematologists. Through course evaluations, all trainees described that the didactic sessions were relevant. All session types were useful for gaining knowledge and skills, particularly one-on-one meetings. The potential for networking was highly valued. Barriers to trainee applications were the concerns that skill level, proposed research program, and knowledge of English were not sufficiently strong to warrant acceptance into the course, and financial costs of attendance. We have described the development and initial evaluation of a clinical research training program in a LMIC setting. We learned several valuable lessons that are applicable to other research training programs.

American Society of Blood and Marrow Transplantation, European Society of Blood and Marrow Transplantation, Blood and Marrow Transplant Clinical Trials Network, and International Myeloma Working Group Consensus Conference on Salvage Hematopoietic Cell Transplantation in Patients with Relapsed Multiple Myeloma.

In contrast to the upfront setting in which the role of high-dose therapy with autologous hematopoietic cell transplantation (HCT) as consolidation of a first remission in patients with multiple myeloma (MM) is well established, the role of high-dose therapy with autologous or allogeneic HCT has not been extensively studied in MM patients relapsing after primary therapy. The International Myeloma Working Group together with the Blood and Marrow Transplant Clinical Trials Network, the American Society of Blood and Marrow Transplantation, and the European Society of Blood and Marrow Transplantation convened a meeting of MM experts to: (1) summarize current knowledge regarding the role of autologous or allogeneic HCT in MM patients progressing after primary therapy, (2) propose guidelines for the use of salvage HCT in MM, (3) identify knowledge gaps, (4) propose a research agenda, and (5) develop a collaborative initiative to move the research agenda forward. After reviewing the available data, the expert committee came to the following consensus statement for salvage autologous HCT: (1) In transplantation-eligible patients relapsing after primary therapy that did NOT include an autologous HCT, high-dose therapy with HCT as part of salvage therapy should be considered standard; (2) High-dose therapy and autologous HCT should be considered appropriate therapy for any patients relapsing after primary therapy that includes an autologous HCT with initial remission duration of more than 18 months; (3) High-dose therapy and autologous HCT can be used as a bridging strategy to allogeneic HCT; (4) The role of postsalvage HCT maintenance needs to be explored in the context of well-designed prospective trials that should include new agents, such as monoclonal antibodies, immune-modulating agents, and oral proteasome inhibitors; (5) Autologous HCT consolidation should be explored as a strategy to develop novel conditioning regimens or post-HCT strategies in patients with short (less than 18 months remissions) after primary therapy; and (6) Prospective randomized trials need to be performed to define the role of salvage autologous HCT in patients with MM relapsing after primary therapy comparing it to "best non-HCT" therapy. The expert committee also underscored the importance of collecting enough hematopoietic stem cells to perform 2 transplantations early in the course of the disease. Regarding allogeneic HCT, the expert committee agreed on the following consensus statements: (1) Allogeneic HCT should be considered appropriate therapy for any eligible patient with early relapse (less than 24 months) after primary therapy that included an autologous HCT and/or high-risk features (ie, cytogenetics, extramedullary disease, plasma cell leukemia, or high lactate dehydrogenase); (2) Allogeneic HCT should be performed in the context of a clinical trial if possible; (3) The role of postallogeneic HCT maintenance therapy needs to be explored in the context of well-designed prospective trials; and (4) Prospective randomized trials need to be performed to define the role salvage allogeneic HCT in patients with MM relapsing after primary therapy.

Survival analysis of transplant-eligible newly-diagnosed multiple myeloma patients harboring t(4;14), t(14;16), and/or del(17p) in the real-world setting.

Cytogenetic abnormalities (CA) such as t(4;14), t(14;16), and del(17p), are associated with a poor prognosis in Multiple Myeloma (MM) patients. However, there is scarce information regarding the Latin-American population. This study aims to analyze the impact of t(4;14), t(14;16), and del(17p) on the progression-free survival (PFS) and overall survival (OS) of transplant-eligible newly-diagnosed MM (NDMM) patients in Latin America. Retrospective survival analysis based on the Grupo de Estudio Latinoamericano de MM (GELAMM) registry, including all adult patients with NDMM harboring CA t(4;14), t(14;16), and/or del(17p). Fifty-nine patients were included; the median age was 57 years, 55.9% males, 22% ISS-I, 25.4% ISS-II, and 47.5% ISS-III. The majority (89.8%) had one alteration, whereas 10.2% had del(17p) and t(4;14). The frequencies of CA were del(17p) in 61.0%, t(4;14) in 25.4%, and t(14;16) in 3,4%. Autologous stem cell transplantation was performed in 36 cases, 20 patients did not use this consolidative strategy, and this data was missed in three cases. Five-year OS for the entire cohort was 60.8% and 5-year PFS was 28.1%. Bortezomib-based induction regimen (BBR) (p=0.029), consolidation with ASCT (p<0.001), and maintenance therapy (p=0.004) were associated with an improved 5-year OS. In the multivariate analysis, ASCT was the only variable with a positive impact on OS (HR 0.11, 95% CI 0.033 to 0.34, p<0.001). The median PFS presented a non-statistically significant benefit in BBR, ASCT, and maintenance therapy groups. BBR induction, ASCT, and maintenance therapy were associated with improved OS in high-risk NDMM patients.

Survival Analysis of Newly Diagnosed Multiple Myeloma Patients after Frontline Autologous Stem Cell Transplantation in a Real-Life Setting.

INTRODUCTION: Autologous stem cell transplantation (ASCT) is the standard consolidation option for transplant-eligible patients with multiple myeloma (MM). The aim of this study is to report the overall survival (OS) and progression-free survival (PFS) outcomes after frontline ASCT in newly-diagnosed MM (NDMM) patients in a real-world setting. METHODS: We conducted a retrospective, survival analysis of all NDMM patients included in the MM Uruguayan Registry. RESULTS: We included 151 NDMM patients treated with induction therapy followed by high-dose melphalan and ASCT as consolidation. The median age at diagnosis was 59 years, and the international staging system (ISS) risk groups were ISS-III 32.9%, ISS-II 37.8%, and ISS-I 29.4%. Frontline induction regimens included bortezomib in 61.6% of cases, and maintenance therapy was used in 63.9% of reported cases. With a median follow-up of 42 months, the 36-month OS and PFS for the whole group were 82.4% (95% CI 75.9% to 89.4%) and 63.8% (95% CI 55.6% to 73.3%), respectively, median OS of 98 months and median PFS of 47 months. The 100-month OS and PFS for the entire group were 48.0% (95% CI 34.9% to 66.0%) and 17.3% (95% CI 8.4% to 35.8%), respectively. CONCLUSION: ASCT is a feasible, safe, and potent strategy that provides a prolonged median OS and PFS in NDMM patients. This approach can be implemented in low-income countries.

Epidemiology and risk factors for the development of infectious complications in newly diagnosed multiple myeloma: a multicenter prospective cohort study in Uruguay.

INTRODUCTION: Infections represent a significant cause of morbidity and mortality in patients with multiple myeloma (MM). In Latin America, data on infectious complications in newly diagnosed MM (NDMM) patients are limited. METHODS: We conducted a multicenter, prospective cohort study of patients with NDMM in Uruguay between June 2019 and December 2020. Patients with active disease, on active therapy and who provided written informed consent were included. Elegible patients were followed for 6 months from the time of diagnosis and before proceeding to autologous stem cell transplantation or until death, whichever occurred first. Our primary endpoint was the number of infectious events that required hospitalization for ≥ 24 h. MAIN RESULTS: Of 124 patients with NDMM, 54 (43.5 %) had infectious complications (74 infectious events), the majority (74.3 %) within the first 3 months from diagnosis. The most common sites of infection were urinary (39.2 %) and respiratory tracts (33.8 %). The microbial agent was identified in 60.8 % of patients with Gram-negative bacteria (71.4 %) as the most common pathogen. Viral and fungal infections were infrequent. In the multivariable analysis, the Eastern Cooperative Oncology Group (ECOG) performance status was ≥ 2 (odds ratio [OR], 2.16; 95 % confidence interval [95 %CI], 1.23 - 3.79; p = 0.008) and creatinine ≥ 2 mg/dl (OR, 2.33; 95 %CI, 1.33 - 4.07; p = 0.003) were independent factors associated with bacterial infections. At 6 months, 14 patients (11.3 %) had died, 50 % related to infectious complications. CONCLUSION: Bacterial infections are a substantial cause of hospital admissions and early death in patients with NDMM. Antibiotic prophylaxis should be considered to reduce infectious complications in patients with MM.

Management of Waldenström Macroglobulinemia in Limited-Resource Settings.

Waldenström macroglobulinemia (WM) is a rare, indolent, and currently incurable B-cell neoplasm characterized by monoclonal immunoglobulin M gammopathy, frequent nodal involvement, and lymphoplasmacytic infiltration of the bone marrow. The clinical pattern at diagnosis is similar to that reported in developed countries but, unfortunately, the tools for a complete diagnosis and access to novel therapies are suboptimal. Older drugs such as bendamustine, cyclophosphamide, and chlorambucil may still play a role in treating WM. Prospective studies in resource-limited regions are required to further evaluate these essential aspects of the disease. In this document, we issue recommendations based on our local reality.

Primary plasma cell leukemia in Latin America: demographic, clinical, and prognostic characteristics. A study of GELAMM group.

Primary plasma cell leukemia (pPCL) is an infrequent and aggressive plasma cell disorder. The prognosis is still very poor, and the optimal treatment remains to be established. A retrospective, multicentric, international observational study was performed. Patients from 9 countries of Latin America (LATAM) with a diagnosis of pPCL between 2012 and 2020 were included. 72 patients were included. Treatment was based on thalidomide in 15%, proteasome inhibitors (PI)-based triplets in 38% and chemotherapy plus IMIDs and/or PI in 29%. The mortality rate at 3 months was 30%. The median overall survival (OS) was 18 months. In the multivariate analysis, frontline PI-based triplets, chemotherapy plus IMIDs and/or PI therapy, and maintenance were independent factors of better OS. In conclusion, the OS of pPCL is still poor in LATAM, with high early mortality. PI triplets, chemotherapy plus IMIDs, and/or PI and maintenance therapy were associated with improved survival.

Patients Age 40 Years and Younger With Multiple Myeloma Have the Same Prognosis as Older Patients: An Analysis of Real-World Patients' Evidence From Latin America.

PURPOSE: Multiple myeloma (MM) is a highly heterogeneous, incurable disease most frequently diagnosed in the elderly. Therefore, data on clinical characteristics and outcomes in the very young population are scarce. PATIENTS AND METHODS: We analyzed clinical characteristics, response to treatment, and survival in 103 patients with newly diagnosed MM age 40 years or younger compared with 256 patients age 41-50 years and 957 patients age 51 years or older. RESULTS: There were no statistical differences in sex, isotype, International Scoring System, renal involvement, hypercalcemia, anemia, dialysis, bony lesions, extramedullary disease, and lactate dehydrogenase (LDH). The most used regimen in young patients was cyclophosphamide, bortezomib, dexamethasone, followed by cyclophosphamide, thalidomide, dexamethasone and bortezomib, thalidomide, dexamethasone. Of the patients age 40 years or younger, only 53% received autologous stem-cell transplant (ASCT) and 71.1% received maintenance. There were no differences in overall survival (OS) in the three patient cohorts. In the multivariate analysis, only high LDH, high cytogenetic risk, and ASCT were statistically associated with survival. CONCLUSION: In conclusion, younger patients with MM in Latin America have similar clinical characteristics, responses, and OS compared with the elderly.

Epidemiology and Risk Factors for the Development of Infectious Complications in Newly Diagnosed Multiple Myeloma: A Multicenter Prospective Cohort Study in Latin America.

PURPOSE: Infections are a significant cause of morbidity and mortality in patients with multiple myeloma (MM). In Latin America, data on infectious complications in this patient population are lacking. METHODS: We conducted a prospective cohort study of patients with newly diagnosed MM (NDMM) in seven Latin American countries between June 2019 and May 2020. Patients with active disease, on active therapy, and with a follow-up of 6 months from the time of diagnosis were included. Our primary end point was the number of infectious events that required hospitalization for ≥ 24 hours. RESULTS: Of 248 patients with NDMM, 89 (35.9%) had infectious complications (113 infectious events), the majority (67.3%) within the first 3 months from diagnosis. The most common sites of infection were respiratory (38%) and urinary tract (31%). The microbial agent was identified in 57.5% of patients with gram-negative bacteria (73.5%) as the most common pathogen. Viral infections were infrequent, and no patients with fungal infection were reported. In the multivariable analysis, diabetes mellitus (odds ratio [OR], 2.71; 95% CI, 1.23 to 6.00; P = .014), creatinine ≥ 2 mg/dL (OR, 4.87; 95% CI, 2.29 to 10.35; P < .001), no use of trimethoprim-sulfamethoxazole prophylaxis (OR, 6.66; 95% CI, 3.43 to 12.92; P < .001), and treatment with immunomodulatory drugs (OR, 3.02; 95% CI, 1.24 to 6.29; P = .003) were independent factors associated with bacterial infections. At 6 months, 21 patients (8.5%) had died, 47.6% related to infectious complications. CONCLUSION: Bacterial infections are a substantial cause of hospital admissions and early death in patients with NDMM. Antibiotic prophylaxis should be considered to reduce infectious complications in patients with MM.

Treatment and Survival Outcomes of Waldenstrom Macroglobulinemia in Latin American Patients: A Multinational Retrospective Cohort Study.

PURPOSE: Waldenstrom Macroglobulinemia (WM) is a rare lymphoma with distinct clinical features, and data from Latin American patients are lacking. Therefore, we aim to investigate the clinical, therapy, and outcome patterns of WM in Latin America. METHODS: We retrospectively analyzed patients with WM diagnosed between 1991 and 2019 from 24 centers in seven Latin American countries. The study outcomes were overall survival (OS) and progression-free survival (PFS). RESULTS: We identified 159 cases (median age 67 years, male 62%). Most patients (95%) were symptomatic at diagnosis. The International Prognostic Scoring System for WM (IPSSWM) at diagnosis was available in 141 (89%) patients (high-risk 40%, intermediate-risk 37%, and low-risk 23%). Twenty-seven (17%) patients were tested for MYD88L265P, with 89% (n = 24 of 27) carrying the mutation. First-line and second-line therapies were administered to 142 (89%) and 53 (33%) patients, respectively. Chemoimmunotherapy was the most commonly used first-line (66%) and second-line (45%) approach; only 18 (11%) patients received ibrutinib. With a median follow-up of 69 months, the 5-year OS rate was 81%. In treated patients, the 5-year OS and PFS rates were 78% and 59%, respectively. High-risk IPSSWM at treatment initiation was an independent risk factor for OS (adjusted hazard ratio: 4.73, 95% CI, 1.67 to 13.41, P = .003) and PFS (adjusted hazard ratio: 2.43, 95% CI, 1.31 to 4.50, P = .005). CONCLUSION: In Latin America, the management of WM is heterogeneous, with limited access to molecular testing and novel agents. However, outcomes were similar to those reported internationally. We validated the IPSSWM score as a prognostic factor for OS and PFS. There is an unmet need to improve access to recommended diagnostic approaches and therapies in Latin America.