Biomedical subjects

Rafael Fonseca

Publications and source records attributed to Rafael Fonseca.

At least 19 recordsLinked to original sources

PubMed2025

Biallelic antigen escape is a mechanism of resistance to anti-CD38 antibodies in multiple myeloma.

Monoclonal antibodies targeting CD38 are a therapeutic mainstay in multiple myeloma (MM). Although they have contributed to improved outcomes, most patients still experience disease relapse, and little is known about tumor-intrinsic mechanisms of resistance to these drugs. Antigen escape has been implicated as a mechanism of tumor-cell evasion in immunotherapy. Yet, it is unknown whether MM cells can develop permanent resistance to anti-CD38 antibodies by acquiring genomic events leading to biallelic disruption of the CD38 gene locus. Here, we analyzed whole-genome and whole-exome sequencing data from patients 701 newly diagnosed MM, 67 patients at relapse with naivety to anti-CD38 antibodies, and 50 patients collected at relapse after anti-CD38 antibodies. We report a loss of CD38 in 10 of 50 patients (20%) after CD38 therapy, 3 of whom exhibited a loss of both copies. Two of these cases showed convergent evolution in which distinct subclones independently acquired similar advantageous variants. Functional studies on missense mutations involved in biallelic CD38 events revealed that 2 variants, L153H and C275Y, decreased binding affinity and antibody-dependent cellular cytotoxicity of the commercial antibodies daratumumab and isatuximab. However, a third mutation, R140G, conferred selective resistance to daratumumab, while retaining sensitivity to isatuximab. Clinically, patients with MM are often rechallenged with CD38 antibodies after disease progression and these data suggest that next-generation sequencing may play a role in subsequent treatment selection for a subset of patients.

Humans↗

PubMed2006

Tumor suppressor p16 methylation in multiple myeloma: biological and clinical implications.

The biological and clinical implications of p16 gene methylation in multiple myeloma (MM) are still unclear despite previous studies. In this comprehensive study, using methylation-specific PCR (MS-PCR), we show that p16 methylation is relatively common and occurs in monoclonal gammopathy of undetermined significance (MGUS; n=17), smoldering multiple myeloma (SMM; n=40), and MM (n=522) at a prevalence of 24%, 28%, and 34%, respectively. However, p16 methylation does not appear to affect gene expression level. In a large cohort of patients with long-term follow-up information (n=439), there was no difference in overall survival between patients with or without p16 methylation. We also found no association between p16 methylation and the main cytogenetic categories, although it was more common among patients with 17p13.1 deletions (p53 locus), a genetic progression event in MM. In addition, p16 methylation has no apparent effect on the cycle because there was also no difference in the plasma cell labeling index (a direct measurement of proliferation) between patients with and without p16 methylation. Our results question a major role for p16 methylation in the oncogenesis of the PC neoplasm, and we now believe p16 methylation may be a marker for overall epigenetic changes associated with disease progression, with no obvious direct biological or clinical consequences.

Cell Cycle↗

PubMed2006

Gene-expression profiling of Waldenstrom macroglobulinemia reveals a phenotype more similar to chronic lymphocytic leukemia than multiple myeloma.

Waldenström macroglobulinemia (WM) is a B-cell malignancy characterized by the ability of the B-cell clone to differentiate into plasma cells. Although the clinical syndrome and the pathologic characteristics are well defined, little is known about its biology and controversy still exists regarding its cell of origin. In this gene-expression study, we compared the transcription profiles of WM with those of other malignant B cells including (chronic lymphocytic leukemia [CLL] and multiple myeloma [MM]) as well as normal cells (peripheral-blood B cells and bone marrow plasma cells). We found that WM has a homogenous gene expression regardless of 6q deletion status and clusters with CLL and normal B cells on unsupervised clustering with very similar expression profiles. Only a small gene set has expression profiles unique to WM compared to CLL and MM. The most significantly up-regulated gene is IL6 and the most significantly associated pathway for this set of genes is MAPK signaling. Thus, IL6 and its downstream signaling may be of biologic importance in WM. Further elucidation of the role of IL-6 in WM is warranted as this may offer a potential therapeutic avenue.

Antigens, CD↗

PubMed2006

Flavopiridol in patients with relapsed or refractory multiple myeloma: a phase 2 trial with clinical and pharmacodynamic end-points.

Flavopiridol downregulates anti-apoptotic regulators including Mcl-1, upregulates p53, globally attenuates transcription through inhibition of P-TEFb, binds to DNA, and inhibits angiogenesis. Eighteen myeloma patients were treated with 1-hour flavopiridol infusions for 3 consecutive days every 21 days. Immunoblotting for Mcl-1, Bcl-2, p53, cyclin D, phosphoRNA polymerase II and phosphoSTAT 3 was conducted on myeloma cells. Ex vivo flavopiridol treatment of cells resulted in cytotoxicity, but only after longer exposure times at higher flavopiridol concentrations than were anticipated to be achieved in vivo. No anti-myeloma activity was observed in vivo. As administered, flavopiridol has disappointing activity as a single agent in advanced myeloma.

Aged↗

PubMed2006

Analysis of genetic abnormalities provides insights into genetic evolution of hyperdiploid myeloma.

Aneuploidy is ubiquitous in human cancer and is seen as whole chromosome gains and losses, unbalanced translocations and inversions, duplications, deletions and loss of heterozygosity. Within this complexity, some subgroups of aneuploid tumors emerge as distinct biological and clinical entities. Hyperdiploid myeloma (H-MM), characterized by hyperdiploid chromosome numbers because of nonrandom trisomies, is one such example. We undertook a comprehensive survey of the karyotypes of a large number of H-MM (n = 469) to describe fully genomic instability in these tumors, to dissect pathways of genetic evolution, and identify distinct subgroups based on their genetic changes. While selective pressure apparently favors the emergence of clones with gains of chromosomes 3, 5, 7, 9, 11, 15, 19, and 21, a background of ongoing genomic instability results in gains of other chromosomes, albeit at a much lower prevalence. A deduced temporal analysis of these karyotypes indicates that selected gains are early events. Other events occurring later in the course of the disease include secondary chromosome translocations and monosomies. The development of these genetic aberrations is thus highly ordered and undoubtedly of biological relevance. Within this framework, we propose a model of genetic evolution in H-MM.

Chromosome Aberrations↗

PubMed2006

6q deletion discriminates Waldenström macroglobulinemia from IgM monoclonal gammopathy of undetermined significance.

IgM monoclonal gammopathy of undetermined significance (IgM MGUS) and Waldenström macroglobulinemia (WM) are sometimes clinically difficult to distinguish. In our previous study, deletion of the long arm of chromosome 6 (6q) was found in about half of WM patients. To further clarify the area of minimal deletion at 6q (6q-) and to address the issue of whether 6q- occurs in IgM MGUS, 12 IgM MGUS and 38 WM patients were studied by fluorescence in situ hybridization using probes targeting different chromosomal segments of 6q. No 6q deletions were found in IgM MGUS samples. Of 38 successfully studied WM patients, 21 (55%) showed a deletion of 6q. The area of minimal deletion was between 6q23 and 6q24.3, but the deletion usually encompassed a large fragment of the 6q arm. These results indicate that 6q- can distinguish WM from IgM MGUS and is likely to be a secondary event.

Aged↗

PubMed2006

A phase II trial of imatinib in patients with refractory/relapsed myeloma.

Although imatinib was designed to specifically inhibit the bcr-abl gene product, it inhibits other receptor tyrosine kinases including c-kit. As pre-clinical data, 126 patients with plasma cell disorders and 19 controls were evaluated for c-kit expression. Patients were eligible for the treatment trial if they had relapsed/refractory myeloma. The primary end-point of the study was response. Of the 145 studied before the trial, c-kit expression was present on the bone marrow plasma cells of control (11%), AL amyloid (53%), MGUS (47%), SMM (67%) and MM (42%) patients. Twenty-three MM patients were enrolled on the therapeutic trial (imatinib 400 mg daily) and 52% had positive c-kit staining. There were no responses. The median duration of treatment was 48 days (range: 12-349). Patients ended treatment due to progressive disease (18 patients), death (3) and other (2). The data suggest that imatinib is not an active agent in patients with relapsed or refractory multiple myeloma.

Aged↗

PubMed2006

Natural history of thromboembolism in AL amyloidosis.

To determine the natural history of thromboembolism in patients with biopsy-proven AL amyloidosis, medical records of 2,132 patients evaluated at Mayo Clinic between 1975 and 2000 were reviewed. Forty patients (21 male) were found to have objectively documented thromboembolism. The median age was 65 years. Four patients had a monoclonal gammopathy of undetermined significance, 20 had an unspecified plasma cell proliferative disorder, 11 had multiple myeloma, and 1 had Waldenström macroglobulinemia. Twelve patients had cardiac amyloid, and 20 had renal amyloid. Neither the extent of the amyloid nor the type of monoclonal protein was predictive of the development of thromboembolic events. Thromboembolism preceded the diagnosis of AL amyloidosis in 11 patients, occurred at the time of diagnosis or within 1 month after diagnosis in 11 patients, and occurred 1 month or more after diagnosis in 18 patients. Twenty-nine patients (73%) had venous thrombosis and 11 (28%) had arterial thrombosis. Eight patients (20%) died within 1 month after the thrombotic event, and 18 (45%) died within 1 year. The development of thrombosis in patients with AL amyloidosis appears to predict significant mortality within the first month and year after the event.

Aged↗

PubMed2006

Prognostic model for disease-specific and overall mortality in newly diagnosed symptomatic patients with Waldenstrom macroglobulinaemia.

We sought to define prognostic factors for survival in Waldenstrom macroglobulinaemia (WM). Of 585 patients diagnosed with WM and seen at Mayo Clinic between 1960 and 2001, 337 symptomatic patients met the inclusion criteria and were analysed for overall and disease-specific survival. The median survival from the time of diagnosis was 6.4 years. The median disease-specific survival was 11.2 years. Univariate analysis for overall survival identified the following adverse prognostic factors: age >65 years (P < 0.001), organomegaly (P < 0.001), elevated beta2-microglobulin (<0.001), anaemia (Hb < 10.0 g/dl) (P = 0.01), leucopenia (<4.0 x 10(9)/l) (P = 0.03), thrombocytopenia (<150 x 10(9)/l) (P = 0.01), serum albumin <40 g/l (P = 0.001), and quantitative IgM < 0.4 g/l (P = 0.04). On multivariate analysis, age >65 years and organomegaly were associated with poor prognosis. A prognostic model was built based on these two variables. Patients at high risk (1-2 risk factors, median survival 4.2 years) experienced worse survival than patients at low risk (0 risk factors, median survival 10.6 years), P < 0.001. The prognostic model was validated in 204 patients who were not included in the analysis cohort. Beta2-microglobulin > or =4 mg/l was associated with a threefold increase in the risk of death when added to the prognostic model. We describe a simple prognostic model for overall survival for newly diagnosed patients with WM.

Adult↗

PubMed2006

Mayo clinic consensus statement for the use of bisphosphonates in multiple myeloma.

Bisphosphonates are effective in the prevention and treatment of bone disease in multiple myeloma (MM). Osteonecrosis of the jaw is Increasingly recognized as a serious complication of long-term bisphosphonate therapy. Issues such as the choice of bisphosphonate and duration of therapy have become the subject of intense debate given patient safety concerns. We reviewed available data concerning the use of bisphosphonates in MM. Guidelines for the use of bisphosphonates in MM were developed by a multidisciplinary panel consisting of hematologists, dental specialists, and nurses specializing in the treatment of MM. We conclude that intravenous pamidronate and intravenous zoledronic acid are equally effective and superior to placebo in reducing skeletal complications. Pamidronate is favored over zoledronic acid until more data are available on the risk of complications (osteonecrosis of the jaw). We recommend discontinuing bisphosphonates after 2 years of therapy for patients who achieve complete response and/or plateau phase. For patients whose disease is active, who have not achieved a response, or who have threatening bone disease beyond 2 years, therapy can be decreased to every 3 months. These guidelines were developed in the Interest of patient safety and will be reexamined as new data emerge regarding risks and benefits.

Bone Density Conservation Agents↗

PubMed2005

Clinical implication of centrosome amplification in plasma cell neoplasm.

The mechanisms underlying aneuploidy in multiple myeloma (MM) are unclear. Centrosome amplification has been implicated as the cause of chromosomal instability in a variety of tumors and is a potential mechanism causing aneuploidy in MM. Using immunofluorescent (IF) staining, centrosome amplification was detected in 67% of monoclonal gammopathies, including monoclonal gammopathy of undetermined significance (MGUS). We also investigated the gene expression of centrosome proteins. Overall, gene expression data correlated well with IF-detected centrosome amplification, allowing us to derive a gene expression-based centrosome index (CI) as a surrogate for centrosome amplification. Clinically, MM patients with high CI (> 4) are associated with poor prognostic genetic and clinical subtypes (chromosome 13 deletion, t(4; 14), t(14;16), and PCLI > 1%, P < .05) and are shown here to have short survival (11.1 months versus 39.1 months, P < .001). On multivariate regression, a high CI is an independent prognostic factor. Given that centrosome amplification is already observed in MGUS and probably integral to early chromosomal instability and myeloma genesis, and patients with more extensive centrosome amplification have shorter survival, the mechanisms leading to centrosome amplification should be investigated because these may offer new avenues for therapeutic intervention.

Adult↗

PubMed2005

Phase III clinical trial of thalidomide plus dexamethasone compared with dexamethasone alone in newly diagnosed multiple myeloma: a clinical trial coordinated by the Eastern Cooperative Oncology Group.

PURPOSE: To determine if thalidomide plus dexamethasone yields superior response rates compared with dexamethasone alone as induction therapy for newly diagnosed multiple myeloma. PATIENTS AND METHODS: Patients were randomly assigned to receive thalidomide plus dexamethasone or dexamethasone alone. Patients in arm A received thalidomide 200 mg orally for 4 weeks; dexamethasone was administered at a dose of 40 mg orally on days 1 to 4, 9 to 12, and 17 to 20. Cycles were repeated every 4 weeks. Patients in arm B received dexamethasone alone at the same schedule as in arm A. RESULTS: Two hundred seven patients were enrolled: 103 were randomly assigned to thalidomide plus dexamethasone and 104 were randomly assigned to dexamethasone alone; eight patients were ineligible. The response rate with thalidomide plus dexamethasone was significantly higher than with dexamethasone alone (63% v 41%, respectively; P = .0017). The response rate allowing for use of serum monoclonal protein levels when a measurable urine monoclonal protein was unavailable at follow-up was 72% v 50%, respectively. The incidence rates of grade 3 or higher deep vein thrombosis (DVT), rash, bradycardia, neuropathy, and any grade 4 to 5 toxicity in the first 4 months were significantly higher with thalidomide plus dexamethasone compared with dexamethasone alone (45% v 21%, respectively; P < .001). DVT was more frequent in arm A than in arm B (17% v 3%); grade 3 or higher peripheral neuropathy was also more frequent (7% v 4%, respectively). CONCLUSION: Thalidomide plus dexamethasone demonstrates significantly superior response rates in newly diagnosed myeloma compared with dexamethasone alone. However, this must be balanced against the greater toxicity seen with the combination.

Adult↗

PubMed2005

Prognostic and therapeutic significance of myeloma genetics and gene expression profiling.

Molecular diagnostic tools and novel therapeutics now offer the potential for accurate prognostic and personalized treatment road maps for patients with multiple myeloma (MM). We will review the evidence and provide specific recommendations for routine clinical molecular genetic testing and use of such information to guide therapeutic decision making. In particular, the negative prognostic impact of specific IgH translocations such as the t(4;14), t(14;16), chromosome 13 deletion by conventional cytogenetics and loss of 17p13 by interphase fluorescence in situ hybridization are now established. Preliminary gene expression profiling studies have also demonstrated that individual genes (CSK1-B) or groups of genes can define prognosis with greater accuracy than conventional genetic markers and can provide pharmacogenomic and biologic insight into the pathophysiology, therapeutics, and future targets of myeloma. Importantly, we recommend that all clinical trials now adopt routine genetic testing and risk stratification.

Chromosome Aberrations↗

PubMed2005

Combination therapy with lenalidomide plus dexamethasone (Rev/Dex) for newly diagnosed myeloma.

We report the results of a phase 2 trial using lenalidomide plus dexamethasone (Rev/Dex) as initial therapy for myeloma. Thirty-four patients were enrolled. Lenalidomide was given orally 25 mg daily on days 1 to 21 of a 28-day cycle. Dexamethasone was given orally 40 mg daily on days 1 to 4, 9 to 12, and 17 to 20 of each cycle. Objective response was defined as a decrease in serum monoclonal protein level by 50% or greater and a decrease in urine M protein level by at least 90% or to a level less than 200 mg/24 hours, confirmed by 2 consecutive determinations at least 4 weeks apart. Thirty-one of 34 patients achieved an objective response, including 2 (6%) achieving complete response (CR) and 11 (32%) meeting criteria for both very good partial response and near complete response, resulting in an overall objective response rate of 91%. Of the 3 remaining patients not achieving an objective response, 2 had minor response (MR) and one had stable disease. Forty-seven percent of patients experienced grade III or higher nonhematologic toxicity, most commonly fatigue (15%), muscle weakness (6%), anxiety (6%), pneumonitis (6%), and rash (6%). Rev/Dex is a highly active regimen with manageable side effects in the treatment of newly diagnosed myeloma.

Adult↗

PubMed2005

Prognostic value of circulating plasma cells in monoclonal gammopathy of undetermined significance.

PURPOSE: Monoclonal gammopathy of undetermined significance (MGUS) progresses to multiple myeloma or another related plasma cell disorder (PCD) at a rate of approximately 1% per year. Identification of patients with MGUS at high risk of progression will allow development of preventive strategies. We studied the prognostic value of circulating plasma cells (PCs) in patients with MGUS to predict progression. PATIENTS AND METHODS: Patients were eligible for this retrospective analysis if they were seen at the Mayo Clinic between 1984 and 1997, were diagnosed with MGUS, and had an analysis of the peripheral blood for circulating PCs by the slide-based immunofluorescence method. Patients were observed for progression to another PCD. RESULTS: Three hundred twenty-five patients were eligible and 63 (19%) had circulating PCs. Patients with circulating PCs were twice as likely (hazard ratio, 2.1) to experience progression to another PCD (most commonly myeloma), compared with those without circulating PCs (95% CI, 1.1 to 4.3; P = .03). In patients with circulating PCs, the median progression-free survival was 138 months compared with a median not yet reached for those without circulating PCs (P = .028). The median overall survival also was shorter for those with circulating PCs. Other factors with prognostic value were high levels of M protein and non-immunoglobulin G heavy-chain type. CONCLUSION: The presence of circulating PCs, especially when combined with other known prognostic factors such as M protein concentration and immunoglobulin isotype, identify a group of individuals with MGUS at higher risk of progression to overt multiple myeloma.

Adolescent↗

PubMed2005

Relationship of patient survival and chromosome anomalies detected in metaphase and/or interphase cells at diagnosis of myeloma.

The clinical efficacy of evaluating genetic anomalies in metaphase cells versus interphase nuclei for multiple myeloma (MM) is poorly understood. Therefore, survival for 154 patients with newly diagnosed untreated MM was compared with results from analysis of metaphase and interphase cells. Metaphases were studied by conventional cytogenetics and fluorescent-labeled DNA probes (fluorescence in situ hybridization [FISH]), whereas inter-phase nuclei were evaluated only by FISH. All FISH studies were done using DNA probes to detect t(4;14)(p16;q32), t(11;14)(q13;q32), t(14;16)(q32;q23), del(17) (p13.1), and chromosome 13 anomalies. Metaphases were abnormal by cytogenetics and/or metaphase FISH in 61 (40%) patients. Abnormal interphase nuclei were observed in 133 (86%) patients, including each patient with abnormal metaphases. FISH was a necessary adjunct to cytogenetics to detect t(4;14) and t(14;16) in metaphase cells. Patient survival was especially poor for patients with greater than 50% abnormal interphase nuclei, although this result was more likely due to level of plasma cells than specific chromosome anomalies. For metaphase data, patients with t(4;14), t(14;16), del(17) (p13.1), and/or chromosome 13 anomalies (primarily monosomy 13) had poor survival. A different outcome was observed for interphase data as patients with t(4;14) or t(14;16) had poor survival, whereas patients with chromosome 13 anomalies had intermediate survival: interphase FISH did not substitute for metaphase analysis.

Adult↗

PubMed2005

Phase II trial of single-agent temsirolimus (CCI-779) for relapsed mantle cell lymphoma.

PURPOSE: Mantle cell lymphoma (MCL) is characterized by a t(11;14) resulting in overexpression of cyclin D1 messenger RNA. This study tested whether temsirolimus (previously known as CCI-779), an inhibitor of the mammalian target of rapamycin kinase that regulates cyclin D1 translation, could produce tumor responses in patients with MCL. PATIENTS AND METHODS: Patients with relapsed or refractory MCL were eligible to receive temsirolimus 250 mg intravenously every week as a single agent. Patients with a tumor response after six cycles were eligible to continue drug for a total of 12 cycles or two cycles after complete remission, and were then observed without maintenance. RESULTS: Thirty-five patients were enrolled and were assessable for toxicity; one patient had MCL by histology but was cyclin D1 negative and was ineligible for efficacy. The median age was 70 years (range, 38 to 89 years), 91% were stage 4, and 69% had two or more extranodal sites. Patients had received a median of three prior therapies (range, one to 11), and 54% were refractory to the last treatment. The overall response rate was 38% (13 of 34 patients; 90% CI, 24% to 54%) with one complete response (3%) and 12 partial responses (35%). The median time-to-progression in all patients was 6.5 months (95% CI, 2.9 to 8.3 months), and the duration of response for the 13 responders was 6.9 months (95% CI, 5.2 to 12.4 months). Hematologic toxicities were the most common, with 71% (25 of 35 patients) having grade 3 and 11% (four of 35 patients) having grade 4 toxicities observed. Thrombocytopenia was the most frequent cause of dose reductions but was of short duration, typically resolving within 1 week. CONCLUSIONS: Single-agent temsirolimus has substantial antitumor activity in relapsed MCL. This study demonstrates that agents that selectively target cellular pathways dysregulated in MCL cells can produce therapeutic benefit. Further studies of this agent in MCL and other lymphoid malignancies are warranted.

Adult↗

PubMed2005

Clinical implications of t(11;14)(q13;q32), t(4;14)(p16.3;q32), and -17p13 in myeloma patients treated with high-dose therapy.

Fluorescence in situ hybridization (FISH) is more sensitive than conventional cytogenetics for recognizing chromosomal changes. Several FISH-detected abnormalities have been associated with inferior prognosis, including deletion of chromosomes 17 and 13 (Delta13) and t(4;14)(p16.3;q32). We analyzed the prognostic value of FISH testing in 238 patients who received high-dose therapy between January 1990 and September 2001. All patients had pretransplantation cytoplasmic immunoglobulin FISH done on cytospin slides from bone marrow aspirates for t(11;14), t(4;14), and -17(p13.1) (TP53). Time to progression and overall survival were significantly shorter for patients with t(4;14) and those with -17(p13.1) but were not affected by t(11;14). Overall survival was significantly shorter for patients with both t(4;14) and Delta13 abnormalities than for those with Delta13 alone (26.8 vs 18.8 months). In a multivariable analysis of the effect of Delta13 and t(4;14), the risk ratio for t(4;14) was greater than for Delta13 (2.6 vs 1.5). For high-dose therapy patients, -17(p13) and t(4;14) have clinical importance for estimating time to progression and overall survival. The presence of t(4;14) identifies a subset of patients whose time to progression is only 8.2 months. These patients receive minimal benefit from autologous stem cell transplantation and are candidates for novel therapeutic approaches.

Adult↗