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Summary: The phase 3 PANORAMA‐1 trial led to regulatory approvals of panobinostat (PAN) in combination with bortezomib (BTZ) and dexamethasone (DEX) for the treatment of multiple myeloma after ≥2 prior regimens, including BTZ and an immunomodulatory drug. Patient‐reported outcomes (PROs) were assessed in PANORAMA‐1, with data available for 73 patients in the PAN + BTZ + DEX arm and 74 patients in the placebo (PBO) + BTZ + DEX arm. Per the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire‐Core 30 (EORTC QLQ‐C30), global health status/quality of life (QoL) scores initially declined with PAN + BTZ + DEX during the first 24 weeks before approaching baseline scores and remaining steady during the next 24 weeks, with no difference between arms at Week 48. The EORTC QLQ‐Myeloma module (EORTC QLQ‐MY20) demonstrated initial improvements and subsequent stabilization of disease symptom scores in both arms and initial worsening and subsequent improvement of side effects of treatment scores, with the initial worsening more pronounced and recovery less pronounced with PAN + BTZ + DEX. Functional Assessment of Cancer Therapy/Gynecologic Oncology Group‐Neurotoxicity scores remained relatively stable and similar between the arms. Overall, these PRO findings support the addition of PAN to the BTZ+DEX regimen as an efficacious treatment option, with limited symptomatology and impact on patients’ QoL. The reported results are based on a descriptive analysis of the data. No formal statistical tests have been performed. [ABSTRACT FROM AUTHOR]

Panobinostat is a potent pan-deacetylase inhibitor that affects the growth and survival of multiple myeloma (MM) cells through alteration of epigenetic mechanisms and protein metabolism. Panobinostat plus bortezomib and dexamethasone (PAN-BTZ-Dex) led to a significant increase in progression-free survival (PFS) vs placebo plus bortezomib and dexamethasone (Pbo-BTZ-Dex) in patients with relapsed or relapsed and refractory MM in the phase 3 PANORAMA 1 trial. This subgroup analysis evaluated outcomes in patients in the PANORAMA 1 trial based on prior treatment: a prior immunomodulatory drug (IMiD; n = 485), prior bortezomib plus an IMiD (n = 193), and ≥2 prior regimens including bortezomib and an IMiD (n = 147). Median PFS with PAN-BTZ-Dex vs Pbo-BTZ-Dex across subgroups was as follows: prior IMiD (12.3 vs 7.4 months; hazard ratio [HR], 0.54; 95% confidence interval [CI], 0.43-0.68), prior bortezomib plus IMiD (10.6 vs 5.8 months; HR, 0.52; 95% CI, 0.36-0.76), and ≥2 prior regimens including bortezomib and an IMiD (12.5 vs 4.7 months; HR, 0.47; 95% CI, 0.31-0.72). Common grade 3/4 adverse events and laboratory abnormalities in patients who received PAN-BTZ-Dex across the prior treatment groups included thrombocytopenia, lymphopenia, neutropenia, diarrhea, and asthenia/fatigue. Incidence of on-treatment deaths among patients who received prior bortezomib and an IMiD (regardless of number of prior regimens) was similar between treatment arms. This analysis demonstrated a clear PFS benefit of 7.8 months with PAN-BTZ-Dex among patients who received ≥2 prior regimens including bortezomib and an IMiD, a population with limited treatment options and poorer prognosis. [ABSTRACT FROM AUTHOR]

Recently, outcomes for patients with multiple myeloma have improved dramatically due to improved and innovative therapies. However, most patients will either relapse or become refractory to current therapy. Thus, a significant unmet need remains for novel agents to treat this patient population. Panobinostat, a potent pan-deacetylase inhibitor with a unique mechanism of action targeting both epigenetic regulation of gene expression and protein metabolism, has preclinical synergy with a number of agents, including the proteasome inhibitor bortezomib. In a phase 3 trial of panobinostat with bortezomib and dexamethasone, addition of panobinostat significantly prolonged the median progression-free survival of patients with relapsed or relapsed and refractory multiple myeloma. This review focuses on clinical development of panobinostat, with particular emphasis on pharmacokinetics and adverse event management. [ABSTRACT FROM PUBLISHER]

The proteasome inhibitor bortezomib is an effective therapy for the treatment of relapsed and refractory multiple myeloma (RRMM); however, prolonged treatment can be associated with toxicity, peripheral neuropathy and drug resistance. Our earlier studies showed that the novel proteasome inhibitor marizomib is distinct from bortezomib in its chemical structure, mechanisms of action and effects on proteasomal activities, and that it can overcome bortezomib resistance. Pomalidomide, like lenalidomide, has potent immunomodulatory activity and has been approved by the US Food and Drug Administration for the treatment of RRMM. Here, we demonstrate that combining low concentrations of marizomib with pomalidomide induces synergistic anti-MM activity. Marizomib plus pomalidomide-induced apoptosis is associated with: (i) activation of caspase-8, caspase-9, caspase-3 and PARP cleavage, (ii) downregulation of cereblon (CRBN), IRF4, MYC and MCL1, and (iii) suppression of chymotrypsin-like, caspaselike, and trypsin-like proteasome activities. CRBN-siRNA attenuates marizomib plus pomalidomide-induced MM cells death. Furthermore, marizomib plus pomalidomide inhibits the migration of MM cells and tumour-associated angiogenesis, as well as overcomes cytoprotective effects of bone marrow microenvironment. In human MM xenograft model studies, the combination of marizomib and pomalidomide is well tolerated, inhibits tumour growth and prolongs survival. These preclinical studies provide the rationale for on-going clinical trials of combined marizomib and pomalidomide to improve outcome in patients with RRMM. [ABSTRACT FROM AUTHOR]

Toward our goal of personalized medicine, we comprehensively profiled pre-treatment malignant plasma cells from multiple myeloma patients and prospectively identified pathways predictive of favourable response to bortezomib-based treatment regimens. We utilized two complementary quantitative proteomics platforms to identify differentially-regulated proteins indicative of at least a very good partial response ( VGPR) or complete response/near complete response ( CR/ nCR) to two treatment regimens containing either bortezomib, liposomal doxorubicin and dexamethasone ( VDD), or lenalidomide, bortezomib and dexamethasone ( RVD). Our results suggest enrichment of 'universal response' pathways that are common to both treatment regimens and are probable predictors of favourable response to bortezomib, including a subset of endoplasmic reticulum stress pathways. The data also implicate pathways unique to each regimen that may predict sensitivity to DNA-damaging agents, such as mitochondrial dysfunction, and immunomodulatory drugs, which was associated with acute phase response signalling. Overall, we identified patterns of tumour characteristics that may predict response to bortezomib-based regimens and their components. These results provide a rationale for further evaluation of the protein profiles identified herein for targeted selection of anti-myeloma therapy to increase the likelihood of improved treatment outcome of patients with newly-diagnosed myeloma. [ABSTRACT FROM AUTHOR]

Although multiple myeloma remains incurable with conventional treatments, management of the disease has recently been transformed with the introduction of three novel agents, bortezomib, thalidomide, and lenalidomide. The proteasome inhibitor bortezomib is approved for the treatment of patients who have received one prior therapy; there is a growing body of clinical evidence showing its effectiveness alone and in combination in the frontline setting, with high response rates and consistently high rates of complete response. Thalidomide plus dexamethasone is approved as frontline treatment of multiple myeloma. Other combination regimens including thalidomide have demonstrated substantial activity in both relapsed and frontline settings. Recently, the thalidomide analogue lenalidomide has been approved, in combination with dexamethasone, for the treatment of patients who have received one prior therapy; this regimen has shown promising results in the frontline setting. These agents represent a new generation of treatments for multiple myeloma that affect both specific intracellular signaling pathways and the tumor microenvironment. Other novel, targeted therapies are also being evaluated in preclinical and clinical studies. Regimens incorporating bortezomib, thalidomide, lenalidomide, and other novel agents, together with commonly used conventional drugs, represent a promising future direction in myeloma treatment. At present, further investigation is required to assess the safety and activity of combinations integrating these other novel agents. However, bortezomib, thalidomide, and lenalidomide are now in widespread clinical use. This review therefore focuses on the extensive clinical data available from studies of these drugs in the treatment of newly diagnosed and advanced multiple myeloma. [ABSTRACT FROM AUTHOR]

Hematologic malignancies, including multiple myeloma (MM], will account for more than 1OO,OOO new cases of cancer and over 57,000 deaths in the United States in 2003. Treatment of MM is a serious challenge, because despite a variety of available therapies, median survival is short. A new therapeutic area focuses on inhibiting the activity of the proteasome, a 26S protease complex involved in cell cycle regulation, cell adhesion, inflammation, and protein turnover. The novel proteasome inhibitor, 5ortezomi5 (Velcade®), was recently approved for use in patients with refractory and relapsed MM and to date is the only proteasome inhibitor to have entered clinical trials. Borte- zomib has demonstrated activity with manageable toxicity in a variety of hematologic malignancies in addition to MM, including leukemia and non-Hodgkin's lymphoma. This article reviews clinical information on bortezomib in hematologic malignancies both as monotherapy and in combination with dexamethasone. Preliminary reports of bortezomib in combination with Doxil (pegylated liposomal doxorubicin), melphalan, and thalidomide arc discussed, and current trials arc described. Available data suggest that bortezomib will be useful in the treatment of a variety of hematologic malignancies. [ABSTRACT FROM AUTHOR]