Summary
Bone disease is the major feature of multiple myeloma (MM). Imaging is required for correct staging, in the follow‐up after treatment and, as recently highlighted, is predictor of prognosis. ...In the near future, whole‐body X‐Ray may be replaced by more sensitive techniques, such as whole‐body low‐dose computerized tomography (CT). Magnetic resonance imaging (MRI) is the gold standard method for assessing bone marrow infiltration of the spine, predicting the risk of vertebral fracture and distinguishing between benign and malignant osteoporosis. Positron emission tomography (PET) with CT (PET/CT) provides important information about the extent of whole‐body disease, including soft tissue masses, and is the best tool to distinguish between active or inactive disease after therapy. Both MRI and PET/CT are predictors of clinical outcome. A prospective use of these newer imaging techniques in both clinical trials and clinical practice may help optimize MM management in the near future.
Chronic myeloid leukemia (CML) is characterized by the presence of the
fusion gene, which encodes a constitutive active tyrosine kinase considered to be the pathogenic driver capable of initiating ...and maintaining the disease. Despite the remarkable efficacy of tyrosine kinase inhibitors (TKIs) targeting BCR-ABL1, some patients may not respond (primary resistance) or may relapse after an initial response (secondary resistance). In a small proportion of cases, development of resistance is accompanied or shortly followed by progression from chronic to blastic phase (BP), characterized by a dismal prognosis. Evolution from CP into BP is a multifactorial and probably multistep phenomenon. Increase in BCR-ABL1 transcript levels is thought to promote the onset of secondary chromosomal or genetic defects, induce differentiation arrest, perturb RNA transcription, editing and translation that together with epigenetic and metabolic changes may ultimately lead to the expansion of highly proliferating, differentiation-arrested malignant cells. A multitude of studies over the past two decades have investigated the mechanisms underlying the closely intertwined phenomena of drug resistance and disease progression. Here, we provide an update on what is currently known on the mechanisms underlying progression and present the latest acquisitions on BCR-ABL1-independent resistance and leukemia stem cell persistence.
Deregulated activity of BCR-ABL1, a nonreceptor tyrosine kinase encoded by the fusion gene resulting from the t(9;22)(q34;q11) chromosomal translocation, is thought to be the driver event responsible ...for initiation and maintenance of chronic myeloid leukemia (CML). BCR-ABL1 was one of the first tyrosine kinases to be implicated in a human malignancy and the first to be successfully targeted. Imatinib mesylate, the first tyrosine kinase inhibitor (TKI) to be approved for therapeutic use, was hailed as a magic bullet against cancer and remains one of the safest and most effective anticancer agents ever developed. Second- and third-generation TKIs were later introduced to prevent or counteract the problem of drug resistance, that may arise in a small proportion of patients. They are more potent molecules, but have been associated to more serious side effects and complications. Patients achieving stable optimal responses to TKI therapy are predicted to have the same life expectancy of the general population. However, TKIs do not 'cure' CML. Only a small proportion of cases may attempt therapy discontinuation without experiencing subsequent relapse. The great majority of patients will have to assume TKIs indefinitely - which raises serious pharmacoeconomic concerns and is now shifting the focus from efficacy to compliance and quality of life issues. Here we retrace the steps that have led from the biological acquisitions regarding BCR-ABL1 structure and function to the development of inhibitory strategies and we discuss drug resistance mechanism and how they can be addressed.
Summary
With increasing number of therapies available for the treatment of multiple myeloma, it is timely to examine the course of patients' journeys. We investigated patient characteristics, ...treatment durations and outcomes, and symptom burden across the treatment pathway in Belgium, France, Germany, Italy, Spain, Switzerland and the UK. In total, 435 physicians retrospectively reviewed 4997 patient charts. Profiles of patients diagnosed with multiple myeloma during the last 12 months were similar across countries; bone pain was the most common presentation. Median duration of first‐line therapy was 6 months, followed by a median treatment‐free interval of 10 months; both these decreased with increasing lines of therapy, as did time to progression. Depth of response, as assessed by the treating physician, also decreased with each additional line of therapy: 74% of patients achieved at least a very good partial response at first line, compared with only 11% at fifth line. Deeper responses were associated with longer time to progression, although these were physician‐judged. Toxicities and co‐morbidities increased with later treatment lines, and were more likely to have led to discontinuation of treatment. These real‐world data provide an insight into patient outcomes and treatment decisions being made in clinical practice.
The clinical outcome of multiple myeloma (MM) is heterogeneous. A simple and reliable tool is needed to stratify patients with MM. We combined the International Staging System (ISS) with chromosomal ...abnormalities (CA) detected by interphase fluorescent in situ hybridization after CD138 plasma cell purification and serum lactate dehydrogenase (LDH) to evaluate their prognostic value in newly diagnosed MM (NDMM).
Clinical and laboratory data from 4,445 patients with NDMM enrolled onto 11 international trials were pooled together. The K-adaptive partitioning algorithm was used to define the most appropriate subgroups with homogeneous survival.
ISS, CA, and LDH data were simultaneously available in 3,060 of 4,445 patients. We defined the following three groups: revised ISS (R-ISS) I (n = 871), including ISS stage I (serum β2-microglobulin level < 3.5 mg/L and serum albumin level ≥ 3.5 g/dL), no high-risk CA del(17p) and/or t(4;14) and/or t(14;16), and normal LDH level (less than the upper limit of normal range); R-ISS III (n = 295), including ISS stage III (serum β2-microglobulin level > 5.5 mg/L) and high-risk CA or high LDH level; and R-ISS II (n = 1,894), including all the other possible combinations. At a median follow-up of 46 months, the 5-year OS rate was 82% in the R-ISS I, 62% in the R-ISS II, and 40% in the R-ISS III groups; the 5-year PFS rates were 55%, 36%, and 24%, respectively.
The R-ISS is a simple and powerful prognostic staging system, and we recommend its use in future clinical studies to stratify patients with NDMM effectively with respect to the relative risk to their survival.
Proteasome inhibition has emerged as an important therapeutic strategy in multiple myeloma (MM). Since the publication of the first phase 1 trials of bortezomib 10 years ago, this first-in-class ...proteasome inhibitor (PI) has contributed substantially to the observed improvement in survival in MM patients over the past decade. Although first approved as a single agent in the relapsed setting, bortezomib is now predominantly used in combination regimens. Furthermore, the standard twice-weekly schedule may be replaced by weekly infusion, especially when bortezomib is used as part of combination regimens in frontline therapy. Indeed, bortezomib is an established component of induction therapy for patients eligible or ineligible for autologous stem cell transplantation. Bortezomib has also been incorporated into conditioning regimens before autologous stem cell transplantation, as well as into post-ASCT consolidation therapy, and in the maintenance setting. In addition, a new route of bortezomib administration, subcutaneous infusion, has recently been approved. Recently, several new agents have been introduced into the clinic, including carfilzomib, marizomib, and MLN9708, and trials investigating these “second-generation” PIs in patients with relapsed/refractory MMs have demonstrated positive results. This review provides an overview of the role of PIs in the treatment of MM, focusing on developments over the past decade.
In this Policy Review, the Bone Working Group of the International Myeloma Working Group updates its clinical practice recommendations for the management of multiple myeloma-related bone disease. ...After assessing the available literature and grading recommendations using the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) method, experts from the working group recommend zoledronic acid as the preferred bone-targeted agent for patients with newly diagnosed multiple myeloma, with or without multiple myeloma-related bone disease. Once patients achieve a very good partial response or better, after receiving monthly zoledronic acid for at least 12 months, the treating physician can consider decreasing the frequency of or discontinuing zoledronic acid treatment. Denosumab can also be considered for the treatment of multiple myeloma-related bone disease, particularly in patients with renal impairment. Denosumab might prolong progression-free survival in patients with newly diagnosed multiple myeloma who have multiple myeloma-related bone disease and who are eligible for autologous stem-cell transplantation. Denosumab discontinuation is challenging due to the rebound effect. The Bone Working Group of the International Myeloma Working Group also found cement augmentation to be effective for painful vertebral compression fractures. Radiotherapy is recommended for uncontrolled pain, impeding or symptomatic spinal cord compression, or pathological fractures. Surgery should be used for the prevention and restoration of long-bone pathological fractures, vertebral column instability, and spinal cord compression with bone fragments within the spinal route.
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.
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