Immunomodulatory drugs lenalidomide and pomalidomide inhibit multiple myeloma-induced osteoclast formation and the RANKL/OPG ratio in the myeloma microenvironment targeting the expression of adhesion molecules

Expert panel consensus statement on the optimal use of pomalidomide in relapsed and refractory multiple myeloma

In this report, a panel of European myeloma experts discuss the role of pomalidomide in the treatment of relapsed and refractory multiple myeloma (RRMM). Based on the available evidence, the combination of pomalidomide and low-dose dexamethasone is a well-tolerated and effective treatment option for patients with RRMM who have exhausted treatment with lenalidomide and bortezomib. The optimal starting dose of pomalidomide is 4 mg given on days 1-21 of each 28-day cycle, whereas dexamethasone is administered at a dose of 40 mg weekly (reduced to 20 mg for patients aged >75 years). The treatment should continue until evidence of disease progression or unacceptable toxicity. Dose-modification schemes have been established for patients who develop neutropenia, thrombocytopaenia and other grade 3-4 adverse events during pomalidomide therapy. Guidance on the prevention and management of infections and venous thromboembolism is provided, based on the available clinical evidence and the experience of panel members. The use of pomalidomide in special populations, such as patients with advanced age, renal impairment or unfavourable cytogenetic features, is also discussed.

Preclinical and clinical results with pomalidomide in the treatment of relapsed/refractory multiple myeloma

Despite the evolution of effective frontline treatment strategies, many patients with myeloma inevitably relapse. Treatment can be complicated by the interplay of disease-, treatment-, and patient-related factors. Unfortunately, many patients eventually develop disease that is refractory to lenalidomide and bortezomib and have few treatment options. Pomalidomide is a distinct IMiD agent recently approved in the US and Europe. We review the pomalidomide mechanism of action, summarizing its direct antimyeloma, immunomodulatory, and stromal-support inhibitory activities. We also detail its clinical development, including establishment of the approved dose/schedule, phase 2 and 3 trials in relapsed and refractory patients, and novel pomalidomide-based combinations.

Pomalidomide in the treatment of relapsed multiple myeloma

The novel agents bortezomib and lenalidomide improve outcomes in multiple myeloma, yet most patients will relapse after exhausting treatment. Management of relapsed and refractory multiple myeloma (RRMM) is challenging owing to disease-, patient- and treatment-related factors, and new therapies for these patients are required. Pomalidomide (POM) is an immunomodulatory compound that has been recently approved in the USA for the treatment of RRMM after two prior therapies, including lenalidomide and bortezomib. POM has several potential mechanisms of action and has a unique pharmacokinetic profile. Several trials demonstrate the efficacy and safety of POM in RRMM, including subjects refractory to lenalidomide and bortezomib. Herein, POM is reviewed as a clinically active new treatment option for RRMM.

Trial Watch: Lenalidomide-based immunochemotherapy

Lenalidomide is a synthetic derivative of thalidomide currently approved by the US Food and Drug Administration for use in patients affected by multiple myeloma (in combination with dexamethasone) and low or intermediate-1 risk myelodysplastic syndromes that harbor 5q cytogenetic abnormalities. For illustrative purposes, the mechanism of action of lenalidomide can be subdivided into a cancer cell-intrinsic, a stromal, and an immunological component. Indeed, lenalidomide not only exerts direct cell cycle-arresting and pro-apoptotic effects on malignant cells, but also interferes with their physical and functional interaction with the tumor microenvironment and mediates a robust, pleiotropic immunostimulatory activity. In particular, lenalidomide has been shown to stimulate the cytotoxic functions of T lymphocytes and natural killer cells, to limit the immunosuppressive impact of regulatory T cells, and to modulate the secretion of a wide range of cytokines, including tumor necrosis factor α, interferon γ as well as interleukin (IL)-6, IL-10, and IL-12. Throughout the last decade, the antineoplastic and immunostimulatory potential of lenalidomide has been investigated in patients affected by a wide variety of hematological and solid malignancies. Here, we discuss the results of these studies and review the status of clinical trials currently assessing the safety and efficacy of this potent immunomodulatory drug in oncological indications.

Diagnosis and treatment of bone disease in multiple myeloma: spotlight on spinal involvement

Bone disease is observed in almost 80% of newly diagnosed symptomatic multiple myeloma patients, and spine is the bone site that is more frequently affected by myeloma-induced osteoporosis, osteolyses, or compression fractures. In almost 20% of the cases, spinal cord compression may occur; diagnosis and treatment must be carried out rapidly in order to avoid a permanent sensitive or motor defect. Although whole body skeletal X-ray is considered mandatory for multiple myeloma staging, magnetic resonance imaging is presently considered the most appropriate diagnostic technique for the evaluation of vertebral alterations, as it allows to detect not only the exact morphology of the lesions, but also the pattern of bone marrow infiltration by the disease. Multiple treatment modalities can be used to manage multiple myeloma-related vertebral lesions. Surgery or radiotherapy is mainly employed in case of spinal cord compression, impending fractures, or intractable pain. Percutaneous vertebroplasty or balloon kyphoplasty can reduce local pain in a significant fraction of treated patients, without interfering with subsequent therapeutic programs. Systemic antimyeloma therapy with conventional chemotherapy or, more appropriately, with combinations of conventional chemotherapy and compounds acting on both neoplastic plasma cells and bone marrow microenvironment must be soon initiated in order to reduce bone resorption and, possibly, promote bone formation. Bisphosphonates should also be used in combination with antimyeloma therapy as they reduce bone resorption and prolong patients survival. A multidisciplinary approach is thus needed in order to properly manage spinal involvement in multiple myeloma.

Maintaining bone health in patients with multiple myeloma: survivorship care plan of the International Myeloma Foundation Nurse Leadership Board

About 90% of individuals with multiple myeloma will develop osteolytic bone lesions from increased osteoclastic and decreased osteoblastic activity. Severe morbidities from pathologic fractures and other skeletal events can lead to poor circulation, blood clots, muscle wasting, compromised performance status, and overall poor survival. Supportive care targeting bone disease is an essential adjunct to antimyeloma therapy. In addition, the maintenance of bone health in patients with multiple myeloma can significantly improve quality of life. Oncology nurses and other healthcare providers play a central role in the management of bone disease and maintenance throughout the course of treatment. Safe administration of bisphosphonates, promotion of exercise, maintenance of adequate nutrition, vitamin and mineral supplementation, scheduled radiographic examinations, and monitoring of bone complications are among the important functions that oncology nurses and healthcare providers perform in clinical practice.