Pharmacokinetic drug evaluation of ixazomib citrate for the treatment of multiple myeloma.

INTRODUCTION: multiple myeloma (MM) is a plasma cell disorder that represents the second most frequent hematologic cancer. Although MM is still an incurable disease, prognosis has improved in the last decades thanks to the introduction of novel agents such as proteasome inhibitors (PIs), immunomodulatory drugs, monoclonal antibodies, and histone deacetylase inhibitors. Areas covered: ixazomib is the first oral PI recently approved by Food and Drug Administration (FDA) and European Medicine Agency (EMA) in combination with lenalidomide and dexamethasone as salvage therapy in MM patients. In this paper, we focus on its pharmacokinetics features, as well as its safety and efficacy in clinical studies. Expert opinion: ixazomib can be considered an oral analogue of bortezomib, with 9.5-day half-life, 58% of oral bioavailability, and a large distribution volume of 543L. These features make it a versatile molecule, potentially useful both in combination and as single agent. Oral route of administration and good efficacy/safety profile are its winning characteristics, providing the rationale for a future role also in the maintenance setting.

Melphalan hydrochloride for the treatment of multiple myeloma.

INTRODUCTION: Multiple myeloma (MM) is an incurable disease characterized by clonal plasma cell proliferation and overproduction of monoclonal paraprotein, hypercalcemia, renal failure, anemia, osteolytic bone lesions, and infections. Melphalan, a nitrogen mustard, is an alkylating agent synthesized in 1953, and it has been used in multiple myeloma therapy for fifty years. Although novel agents have been introduced in the past few decades improving prognosis of the disease, melphalan still maintains a crucial role in the treatment of MM acting both as cytotoxic agent through damage to DNA, and as immunostimulatory drug by inhibiting Interleukin-6, as well as interaction with dendritic cells, and immunogenic effects in tumor microenvironment. Areas covered: This review focuses on available data about melphalan pharmacology and its role in clinical practice. Expert opinion: Melphalan remains crucial in therapy of multiple myeloma because of its good manageability, safety profile, efficacy, and economic sustainability. These characteristics make it pivotal also for new regimens in combination with novel agents.

Minimal residual disease after transplantation or lenalidomide-based consolidation in myeloma patients: a prospective analysis.

We analyzed 50 patients who achieved at least a very good partial response in the RV-MM-EMN-441 study. Patients received consolidation with autologous stem-cell transplantation (ASCT) or cyclophosphamide-lenalidomide-dexamethasone (CRD), followed by Lenalidomide-based maintenance. We assessed minimal residual disease (MRD) by multi-parameter flow cytometry (MFC) and allelic-specific oligonucleotide real-time quantitative polymerase chain reaction (ASO-RQ-PCR) after consolidation, after 3 and 6 courses of maintenance, and thereafter every 6 months until progression. By MFC analysis, 19/50 patients achieved complete response (CR) after consolidation, and 7 additional patients during maintenance. A molecular marker was identified in 25/50 patients, 4/25 achieved molecular-CR after consolidation, and 3 additional patients during maintenance. A lower MRD value by MFC was found in ASCT patients compared with CRD patients (p=0.0134). Tumor burden reduction was different in patients with high-risk vs standard-risk cytogenetics (3.4 vs 5.2, ln-MFC; 3 vs 6 ln-PCR, respectively) and in patients who relapsed vs those who did not (4 vs 5, ln-MFC; 4.4 vs 7.8 ln-PCR). MRD progression anticipated clinical relapse by a median of 9 months while biochemical relapse by a median of 4 months. MRD allows the identification of a low-risk group, independently of response, and a better characterization of the activity of treatments.

Association of RAMP1†rs7590387 with the risk of migraine transformation into medication overuse headache.

OBJECTIVES/BACKGROUND: We herein investigated the role of polymorphisms in calcitonin gene-related peptide (CGRP)-related genes looking at the association of rs3781719 (T > C) in the calcitonin gene-related polypeptide-alpha (CALCA) gene and of rs3754701 (T > A) and rs7590387 (C > G) at the receptor activity modifying 1 (RAMP1) locus with triptan response in patients with migraine without aura (MwoA). In addition, their role was evaluated as risk factors for transformation of episodic migraine into medication overuse headache (MOH). The CGRP has a central role in the pathogenesis of migraine; however, little information is currently available concerning the role of polymorphisms in CGRP-related genes as determinants of clinical response to anti-migraine drugs or as risk factors for migraine chronification. METHODS: Genotyping was conducted retrospectively by real-time polymerase chain reaction allelic discrimination assay in 219 patients with MwoA and 130 with MOH in whom migraine was the primary headache type. Gene variants association was evaluated by logistic regression analysis adjusted by confounding factors. The threshold of statistical significance was set according to the total number of polymorphisms analyzed in the current study and in previous publications arising from overlapping datasets. RESULTS: No evidence of association was found between the three polymorphisms tested and triptan response in MwoA patients. Conversely, carriers of RAMP1 rs7590387GG displayed a lower risk of episodic migraine transformation into MOH (vs C allele carriers, odds ratio [OR]: 0.27, 95% confidence interval [CI]: 0.13-0.57, P = 0.0002; threshold of significance set at P < 0.0029). When genotype distribution for RAMP1 rs7590387 was compared between healthy controls (n = 209) and MOH patients, carriers of rs7590387GG were found at lower risk of developing MOH (OR: 0.43, 95%CI: 0.22-0.85, P = 0.011). CONCLUSION: These results suggest that RAMP1 rs7590387 may have a role in the transformation of episodic migraine into MOH.

Pharmacophore modeling technique applied for the discovery of proteasome inhibitors.

INTRODUCTION: The 26S proteasome has many important roles in the biological functions of the cells, and proteasome inhibitors have multiple and complex activities on cells. These compounds can be natural or synthesized. Most synthetic derivatives have been rationally designed, synthesized and optimized to obtain the best selectivity and increase the activity. The design of chemical entities with desired molecular identification, which plays an important role in biological systems, is provided by pharmacophore modeling. Indeed, pharmacophore models can be established either in a ligand-based manner or in a receptor-based manner. AREAS COVERED: The authors discuss the application of pharmacophore modeling techniques to proteasome inhibitors development. Furthermore, the article reviews the classification of the currently discovered proteasome inhibitors where the principal mechanism of action and clinical application are represented. EXPERT OPINION: In the era of new drug development, database of compounds should be thoroughly evaluated with a combination of methods that consider both pharmacophore- and ligand-based virtual screening. The concept of pharmacophore helps to discover new active compounds and to evaluate their activity. The nature of proteasome inhibitor pharmacophore affects the secondary active-site specificity; indeed, increasing specificity decreases the cytotoxicity of the proteasome inhibitors. It is hypothesized that the balanced simultaneous modulation of a few druggable targets may have superior efficacy and fewer side effects than single-target or combination therapies for the treatment of human cancers. The discovery of new compounds should aim to find more active compounds that improve the compliance of patients.

Pomalidomide for the treatment of relapsed-refractory multiple myeloma: a review of biological and clinical data.

Despite the improvements thanks to the introduction of proteasome inhibitors and immunomodulatory drugs (IMiDs), nearly all myeloma patients eventually become refractory to these drugs. Consequently, the outcome of these patients is very poor. Pomalidomide is a new IMiD with a similar structure to the commonly used IMiD thalidomide and lenalidomide. Pomalidomide exhibited more potent anti-myeloma activity and a similar favorable safety profile compared with thalidomide and lenalidomide. In Phase I-II studies pomalidomide plus low-dose dexamethasone demonstrated activity in myeloma patients refractory to both bortezomib and IMiDs. Based on the results of a Phase III trial, the FDA and EMA agencies granted accelerated approval to pomalidomide, which is now considered a new effective strategy for relapsed and/or refractory myeloma patients. Very promising results were obtained when pomalidomide-dexamethasone was used in combination with other compounds. This review provides updated information about pharmacokinetics, mechanism of action, resistance, clinical efficacy and safety of pomalidomide.

The mechanism of action, pharmacokinetics, and clinical efficacy of carfilzomib for the treatment of multiple myeloma.

INTRODUCTION: The development of novel agents, such as immunomodulatory drugs and proteasome inhibitors, has led to a considerable increment in the response rate (RR) and outcomes for multiple myeloma (MM) patients. Unfortunately, MM patients will inevitably relapse and become resistant to new drugs. This led to the continuous development of novel agents. Carfilzomib is a second-generation proteasome inhibitor, demonstrating promising results in relapsed/refractory (RR) and newly diagnosed (ND) MM patients. AREAS COVERED: Herein, the authors review Phase I and II trials on carfilzomib for the treatment of MM. They also describe the profile of the drug during Phase I escalating doses and evaluate the efficacy of carfilzomib both alone and in combination. Finally, the authors also review and discuss the carfilzomib safety profile. EXPERT OPINION: Clinical trials (Phases I and II) with carfilzomib, used both as single agent or in combination with other therapies, established the maximum tolerated dose and recommended schedule of administration. Preliminary data showed that it had a high efficacy and a good safety profile both in RRMM and NDMM patients. Carfilzomib seems to be effective in patients previously treated with bortezomib. Future Phase II and III studies will better define the role of carfilzomib in the treatment of MM as well as its optimum dose.

Evaluation of the pharmacokinetics, preclinical, and clinical efficacy of lenalidomide for the treatment of multiple myeloma.

INTRODUCTION: Lenalidomide is an oral immunomodulatory drug, which was recently introduced for the treatment of multiple myeloma (MM). It has been used for the treatment of newly diagnosed and relapsed MM patients, as both maintenance and preventive therapy. Available data show a progression-free survival and overall survival improvement associated with this drug. AREAS COVERED: Efficacy results of lenalidomide in Phase I, II, and III trials in MM are reported herein. The recent use of lenalidomide as maintenance and preventive therapy is described. An overview of the most important adverse events is also presented, such as myelosuppression, thromboembolic events, fatigue, dermatologic toxicity, infections, teratogenic potential, and second primary malignancies. The literature reviewed consists of clinical trials published from 2001 to 2012. EXPERT OPINION: Lenalidomide is one of the most important therapeutic agents for MM treatment. Various trials have confirmed its remarkable anticancer activity, alone or combined with high- or low-dose dexamethasone, or other drugs. Lenalidomide-related adverse events can be controlled with dose reductions, supportive therapy, and appropriate prophylaxis.