Alternate day pomalidomide retains anti-myeloma effect with reduced adverse events and evidence of in vivo immunomodulation

Thrombosis in multiple myeloma: mechanisms, risk assessment and management

Multiple myeloma (MM) is associated with an increased risk of venous and arterial thrombosis. Pathophysiologic mechanisms include patient, disease and treatment related factors. Risk assessment models have been developed to determine whichpatients are at highest thrombotic risk and pursuant to this, risk adapted thrombosis prophylaxis has been suggested. Areas in which further basic and clinical research is imperative include the molecular and cellular mechanisms of thrombosis in myeloma, the inclusion of relevant biomarkers in risk assessment scores and controlled clinical trials of VTE prophylaxis and treatment using direct oral anticoagulants.

Cellular immunity in the era of modern multiple myeloma therapy

Multiple myeloma (MM) is a relapsing clonal plasma cell malignancy and incurable thus far. With the increasing understanding of myeloma, highlighting the critical importance of the immune system in the pathogenesis of MM is essential. The immune changes in MM patients after treatment are associated with prognosis. In this review, we summarize currently available MM therapies and discuss how they affect cellular immunity. We find that the modern anti-MM treatments enhance antitumour immune responses. A deeper understanding of the therapeutic activity of individual drugs offers more effective treatment approaches that enhance the beneficial immunomodulatory effects. Furthermore, we show that the immune changes after treatment in MM patients can provide useful prognostic marker. Analysing cellular immune responses offers new perspectives for evaluating clinical data and making comprehensive predictions for applying novel therapies in MM patients.

Pomalidomide and dexamethasone combination with additional cyclophosphamide in relapsed/refractory multiple myeloma (AMN001)-a trial by the Asian Myeloma Network

Pomalidomide is a third generation immunomodulatory drug which in combination with dexamethasone, has been shown to be active in relapsed/refractory multiple myeloma. However, the data in Asian patients remain limited. We conducted a prospective phase two clinical trial in major cancer centers in Singapore, South Korea, Taiwan, Japan and Hong Kong to assess the efficacy and safety of pomalidomide and dexamethasone combination (PomDex) +/− cyclophosphamide in Asian patients with relapsed/refractory multiple myeloma who failed lenalidomide and bortezomib. Patients were treated with pomalidomide (4 mg daily for 21 days every 4 weeks) and dexamethasone (40 mg weekly). If there is less than a minimal response after three cycles of PomDex, cyclophosphamide 300 mg/m² can be added (PomCyDex). A total of 136 patients were enrolled. The median PFS was 9 and 10.8 months for the PomDex and PomCyDex group, respectively. The median OS was 16.3 months. This regimen appears to be active across age groups and prior lines of treatment. This combination was overall well tolerated with grade 3 and 4 adverse events of mainly cytopenias. PomDex is highly active and well-tolerated in Asian patients. The addition of cyclophosphamide can improve the response and outcomes further in patients with suboptimal response to PomDex.

Pomalidomide, cyclophosphamide, and dexamethasone for relapsed multiple myeloma

It is important to have an effective therapy for patients with multiple myeloma (MM) at first relapse, particularly if an autologous stem cell transplant (ASCT) is considered at this stage. This multicenter, phase 2 trial evaluated the efficacy and safety of weekly oral pomalidomide-cyclophosphamide-dexamethasone (PCD) in patients with MM in first relapse after treatment with lenalidomide-bortezomib-dexamethasone (RVD). All patients had received RVD as induction and consolidation therapy, plus lenalidomide maintenance for 1 year (arm A). Half had also received an ASCT after induction (arm B). At MM relapse, all patients received 4 oral cycles of pomalidomide 4 mg (days 1-21), cyclophosphamide 300 mg (days 1, 8, 15, and 22), and dexamethasone 40 mg (days 1-4 and days 15-18 of a 28-day cycle; PCD). Responding patients in arm A underwent ASCT and received 2 additional cycles of PCD, whereas those in arm B received 5 cycles of PCD. All patients received pomalidomide-dexamethasone maintenance until disease progression. Primary end point was partial remission or better after the initial 4 cycles of PCD. Responses were obtained in 82/97 (85%) patients evaluated: complete remission (n = 1; 1%), very good partial remission (n = 32; 33%), and partial remission (n = 49; 51%). Three patients (3%) had stable disease, and 6 (6%) had disease progression (6 response failures). Forty-five (94%) of the 48 patients in arm A underwent planned ASCT. PCD was effective therapy after first relapse with RVD. After 4 cycles, the rate of partial remission or better was 85%, and 94% of planned ASCTs were performed. Toxicity was mostly hematologic and manageable. This trial was registered at www.clinicaltrials.gov as #NCT02244125.

New Insights in Anti-Angiogenesis in Multiple Myeloma

Angiogenesis is a constant hallmark of multiple myeloma (MM) progression and involves direct production of angiogenic cytokines by plasma cells and their induction within the bone marrow microenvironment. This article summarizes the more recent literature data concerning the employment of anti-angiogenic therapeutic agents actually used in preclinical models and clinical settings for the treatment of multiple myeloma.

A historical perspective on milestones in multiple myeloma research

The first well-documented case of multiple myeloma was reported in 1844 by Samuel Solly. In this article, the author presents a historical review of the disease. In particular, the review is focused on the main steps, including the definition of Bence Jones proteinuria, the characterization of tumoral plasma cells and serum globulins, and the fundamental contribution of Jan Waldenstrom. Finally, treatment of multiple myeloma, as well as the development of new agents, is discussed.

Immunotherapy Strategies Against Multiple Myeloma

Multiple myeloma is a monoclonal B-cell malignancy characterized by an accumulation of malignant plasma cells in the bone marrow, the presence of a monoclonal protein in the serum and/or urine, decreased normal immunoglobulin levels, and lytic bone disease. Patients with multiple myeloma benefit from combination therapy including novel therapeutic agents followed by autologous stem cell transplantation prolonged maintenance therapy. However, multiple myeloma remains incurable; most patients with multiple myeloma will eventually become resistant to chemotherapy, and progression or relapse of the disease is inevitable. Immunotherapy represents a novel therapeutic approach with few adverse effects and good targeting capability that might be a powerful pool to allow long-term control of minimal residual disease. This article reviews the literature evaluating 4 major immunotherapeutic approaches for multiple myeloma including cellular immunotherapy, humoral immunotherapy, radio immunotherapy, and immunomodulation.

Thalidomide and its analogues: A review of the potential for immunomodulation of fibrosis diseases and opthalmopathy

The US Food and Drug Administration approved thalidomide and its analogues for the treatment of erythema nodosum leprosum, in spite of the notoriety of reports of severe birth defects in the middle of the last century. As immunomodulatory drugs, thalidomide and its analogues have been used to effectively treat various diseases. In the present review, preclinical data about the effects of thalidomide and its analogues on the immune system are integrated, including the effects of cytokines on transdifferentiation, the anti-inflammatory effect, immune cell function regulation and angiogenesis. The present review also investigates the latest developments of thalidomide as a therapeutic option for the treatment of idiopathic pulmonary fibrosis, skin fibrosis, and ophthalmopathies.

Pomalidomide-dexamethasone in refractory multiple myeloma: long-term follow-up of a multi-cohort phase II clinical trial

Despite therapeutic advances, multiple myeloma remains incurable, with limited options for patients with refractory disease. We conducted a large, multi-cohort clinical trial testing various doses and treatment schedules of pomalidomide and dexamethasone (Pom/dex) in patients with refractory multiple myeloma. Overall, 345 patients were enrolled to six cohorts based on number and type of prior lines of therapy, pomalidomide dose and schedule. Median prior lines of therapy were three with near universal prior exposure to proteasome inhibitors and/or immunomodulatory drugs. A confirmed response rate of 35% was noted for all cohorts (range 23-65%) with higher responses in cohorts with fewer prior lines of therapy. Median time to confirmed response was ⩽2 months and the longest progression-free survival and overall survival seen in any cohort were 13.1 and 47.9 months, respectively. Observed adverse reactions were as expected, with myelosuppression and fatigue being the most common hematologic and non-hematologic adverse events (AEs), respectively. Longer durations of treatment and response, higher response rates and fewer AEs were noted with the 2 mg pomalidomide dose. This is the longest follow-up data for Pom/dex in refractory multiple myeloma and will help shape the real-world utilization of this regimen.

Emerging drugs and combinations to treat multiple myeloma

In the past few years, multiple targeted therapies and immunotherapies including second generation immunomodulatory drugs (pomalidomide) and proteasome inhibitors (carfilzomib, ixazomib), monoclonal antibodies and checkpoint inhibitors were approved for the treatment of myeloma or entered advanced phases of clinical testing. These agents showed significant activity in advanced myeloma and increased the available treatment strategies. Pomalidomide is well-tolerated and effective in patients with relapsed/refractory multiple myeloma who have exhausted any possible treatment with lenalidomide and bortezomib. Carfilzomib, a second-generation proteasome inhibitor, is active as a single agent and in combination with other anti-myeloma agents. Ixazomib is the first oral proteasome inhibitor to be evaluated in myeloma and is associated with a good safety profile and anti-myeloma activity in relapsed/refractory patients, even in those refractory to bortezomib. Monoclonal antibodies and immune checkpoint inhibitors are likely to play a major role in the treatment of myeloma over the next decade. In phase 3 studies, triplet regimens based on these agents combined with a backbone therapy (including lenalidomide, pomalidomide or bortezomib) were more efficacious than doublet regimens in patients with relapsed/refractory multiple myeloma, with limited additional toxic effects. This paper aims to provide an overview of the recent use of these agents for the treatment of myeloma, in particular focusing on the role of multi-agent combinations.

Serendipity in Cancer Drug Discovery: Rational or Coincidence?

Novel drug development leading to final approval by the US FDA can cost as much as two billion dollars. Why the cost of novel drug discovery is so expensive is unclear, but high failure rates at the preclinical and clinical stages are major reasons. Although therapies targeting a given cell signaling pathway or a protein have become prominent in drug discovery, such treatments have done little in preventing or treating any disease alone because most chronic diseases have been found to be multigenic. A review of the discovery of numerous drugs currently being used for various diseases including cancer, diabetes, cardiovascular, pulmonary, and autoimmune diseases indicates that serendipity has played a major role in the discovery. In this review we provide evidence that rational drug discovery and targeted therapies have minimal roles in drug discovery, and that serendipity and coincidence have played and continue to play major roles. The primary focus in this review is on cancer-related drug discovery.

Pomalidomide alone or in combination with dexamethasone in Japanese patients with refractory or relapsed and refractory multiple myeloma

This phase 1, open‐label, dose‐escalation study investigated the tolerated dose (recommended dose), safety, efficacy, and pharmacokinetics of pomalidomide alone or pomalidomide plus low‐dose dexamethasone in Japanese patients with refractory or relapsed and refractory multiple myeloma. Twelve patients were enrolled. Patients received pomalidomide 2 mg (Cohort 1) or 4 mg (Cohort 2) orally on day 1 and days 3–21 of a 28‐day cycle. The tolerated dose of pomalidomide was determined to be 4 mg given on days 1–21 of a 28‐day cycle. Efficacy outcomes with pomalidomide plus low‐dose dexamethasone were consistent with those of previous studies. Responses (partial response or better) were achieved by three patients (25%; 1 [17%] in Cohort 1 and 2 [33%] in Cohort 2), and the median time to response was 6.4 months overall (9.0 months for Cohort 1 and 4.2 months for Cohort 2). The median progression‐free survival was 5.5 months overall (5.1 months for Cohort 1 and not reached for Cohort 2). The most frequently occurring grade ≥3 adverse events were neutropenia (67%), anemia (25%), lymphopenia (25%), and pneumonia (25%), consistent with previous studies of pomalidomide plus low‐dose dexamethasone in refractory or relapsed and refractory multiple myeloma. Further investigation of pomalidomide is recommended for Japanese patients with refractory or relapsed and refractory multiple myeloma. This study was registered with ClinicalTrials.gov (NCT01568294).

Novel drug combinations for the management of relapsed/refractory multiple myeloma

The outcomes and management of multiple myeloma (MM) in the United States have changed dramatically over the past 15 years with the approval by the US Food and Drug Administration (FDA) of 6 new drugs (thalidomide, lenalidomide, bortezomib, pegylated liposomal doxorubicin [Doxil], carfilzomib, and pomalidomide). Despite these advances, a majority of patients with MM relapse, requiring subsequent lines of therapy to manage their disease as a chronic condition. Even though oncologists recognize the heterogeneity in the biology and clinical presentation of patients with newly diagnosed MM, clinical investigations still approach MM in a one-size-fits-all manner. The clinical management becomes even more challenging for relapsed/refractory MM, in which the clinician is balancing disease biology, disease burden, host factors, and financial limitations. There are several new drug targets and antibodies making their way through clinical development, but clinical trials remain an important avenue for patients with relapsed/refractory MM. The present review highlights some of the novel agent combinations in clinical trials that include the 2 most recently approved anti-MM agents, carfilzomib and pomalidomide, and looks ahead toward new drugs and targets in myeloma.

Pomalidomide for the management of refractory multiple myeloma

PURPOSE

The pharmacology, pharmacokinetics, clinical efficacy, safety, dosage and administration, and place in therapy of pomalidomide for the management of refractory multiple myeloma are reviewed.

SUMMARY

Pomalidomide is a second-generation immunomodulatory agent that has been approved by the Food and Drug Administration (FDA) for the management of multiple myeloma refractory to both lenalidomide and bortezomib, with or without the addition of dexamethasone. The overarching mechanism of action is thought to be antiproliferative and directly cytotoxic to malignant plasma cells in the bone marrow. Clinical trials have demonstrated both safety and efficacy with the 4-mg dose given orally on days 1-21 of a 28-day cycle with the possible addition of dexamethasone 40 mg weekly. The most common nonhematologic toxicities found in clinical trials were fatigue, pneumonia, and deep vein thrombosis. The most common hematologic toxicity was neutropenia, which was the only dose-limiting factor of pomalidomide. In order to be able to prescribe and dispense pomalidomide, physicians, patients, and pharmacies must enroll in an FDA-mandated risk evaluation and mitigation strategy program due to the drug's teratogenic effects. Future studies will evaluate the use of pomalidomide with other oncolytic agents, as well as combination regimens with proteasome inhibitors, such as bortezomib, for the management of multiple myeloma.

CONCLUSION

Pomalidomide when administered with weekly low-dose dexamethasone appears to be both safe and effective for the treatment of relapsed or refractory multiple myeloma in patients who have had disease progression after completing treatment with bortezomib, lenalidomide, or both.

Profile of pomalidomide and its potential in the treatment of myelofibrosis

Myelofibrosis, a Philadelphia-negative myeloproliferative neoplasm, is in a new treatment era after the discovery of the JAK2V617F mutation in 2005. JAK inhibitors boast improvements in disease-related symptoms, splenomegaly, and overall survival; however, treatment of myelofibrosis remains a challenge, given the lack of improvement in cytopenias with these agents. Second-generation immunomodulatory agents, such as pomalidomide, have shown efficacy in myelofibrosis-associated anemia within multiple clinical trials. Five major pomalido-mide clinical trials have been completed to date, and demonstrate tolerability and efficacy with low-dose pomalidomide (0.5 mg/day) in the treatment of myelofibrosis, and no clinical benefit of elevated dosing regimens (≥2.5 mg/day). Anemia responses ranged from 17% to 36% as per the International Working Group for Myelofibrosis Research and Treatment consensus guidelines, while improvements in splenomegaly were rare, and observed in <1% of most clinical trials. In comparison with earlier immunomodulatory agents, pomalidomide was associated with an improved toxicity profile, with substantially lower rates of myelosuppression and neuropathy. Given the low overall response rate to pomalidomide as a single agent, combination strategies are of particular interest for future studies. Pomalidomide is currently being tested in combination with ruxolitinib, and other novel combinations are likely on the horizon.

Pomalidomide: evaluation of cytochrome P450 and transporter-mediated drug-drug interaction potential in vitro and in healthy subjects

Pomalidomide offers an alternative for patients with relapsed/refractory multiple myeloma who have exhausted treatment options with lenalidomide and bortezomib. Little is known about pomalidomide's potential for drug-drug interactions (DDIs); as pomalidomide clearance includes hydrolysis and cytochrome P450 (CYP450)-mediated hydroxylation, possible DDIs via CYP450 and drug-transporter proteins were investigated in vitro and in a clinical study. In vitro pomalidomide was neither an inducer nor inhibitor of CYP450, nor an inhibitor of transporter proteins P glycoprotein (P-gp), BCRP, OAT1, OAT3, OCT2, OATP1B1, and OATP1B3. Oxidative metabolism of pomalidomide was predominately mediated by CYP1A2 and CYP3A4, and pomalidomide was shown to be a P-gp substrate. In healthy males, co-administration of oral (4 mg) pomalidomide with ketoconazole (CYP3A/P-gp inhibitor) or carbamazepine (CYP3A/P-gp inducer) did not result in clinically relevant changes in pomalidomide exposure. Co-administration of pomalidomide with fluvoxamine (CYP1A2 inhibitor) in the presence of ketoconazole approximately doubled pomalidomide exposure. Pomalidomide appears to have low potential for clinically relevant DDI and is unlikely to affect the clinical exposure of other drugs. Avoid co-administration of strong CYP1A2 inhibitors unless medically necessary. Pomalidomide dose should be reduced by 50% if co-administered with strong CYP1A2 inhibitors and strong CYP3A/P-gp inhibitors.

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.

Novel agents and new therapeutic approaches for treatment of multiple myeloma

This review summarizes the therapeutic strategies and the drugs actually in development for the management of myeloma patients. Multiple myeloma is caused by the expansion of monoclonal plasma cells and secretion of M-protein (immunoglobulins, Bence Jones protein and free light chains). Multiple myeloma still remains an incurable disease with a high incidence rate in the elderly, despite the introduction of several new therapeutic agents (bortezomib, lenalidomide and thalidomide) which have changed its natural history. The high heterogeneity of this disease leads to large differences in clinical responses to treatments. Thus, the choice of the best treatment is a difficult issue. However, the introduction of new drugs has made it possible to achieve high response rates and good quality responses with long-term disease control. Interactions between tumor cells and their bone marrow microenvironment play a pivotal role in the development, maintenance, and progression of myeloma, inducing also drug resistance. These knowledges have improved treatment options, leading to the approval of new drugs which not only target the malignant cell itself, but also its microenvironment. These agents are in preclinical/early clinical evaluation and they appear to further improve disease control, but their use is still not approved outside of clinical trials.

Pomalidomide in the treatment of multiple myeloma and perspectives in other hematological malignancies

SUMMARY 

Pomalidomide is an immunomodulatory drug recently approved by the US FDA and EMA for the treatment of refractory and relapsed multiple myeloma. Pomalidomide appears to be more potent and less toxic than thalidomide and lenalidomide and has proven to be effective in a proportion of patients already exposed and refractory to these agents. The approved combination of pomalidomide and weekly dexamethasone offers clinical benefit to at least one-third of patients with multiple myeloma that have failed both bortezomib and lenolidomide treatment. This review will focus on the preclinical data and clinical experience in this setting. Off-label use of pomalidomide, mainly its combination with other active drugs for multiple myeloma and the role of pomalidomide in other hematologic malignancies still remain to be explored in depth and are discussed briefly.

Management of double-refractory multiple myeloma

Widespread use of the novel agents bortezomib and lenalidomide has improved outcomes in multiple myeloma (MM). Despite remarkable progress, patients will eventually relapse after exhausting treatment with these drugs. Management of myeloma that is refractory to both bortezomib and lenalidomide (double-refractory MM, DRMM) is complicated due to disease, patient, and treatment-related factors and new therapies for these patients are required. A review of the unique challenges of treating DRMM, recently FDA-approved therapeutic agents, and selected novel drugs under active clinical investigation, is presented below.

A multicenter phase II study of single-agent enzastaurin in previously treated multiple myeloma

Enzastaurin is an oral serine/threonine kinase inhibitor of the protein kinase C (PKC) and phosphatidylinositol 3 (PI3) kinase/Akt pathways that induces apoptosis in multiple myeloma (MM) cell lines in a caspase-independent manner. A phase II study was conducted to assess response rate, time to progression (TTP), safety and biomarker association with clinical outcomes after monotherapy with the PKC inhibitor enzastaurin in previously treated patients with MM. Eligible patients (n = 14) were treated with enzastaurin 250 mg twice daily after receiving loading doses on day 1. One minimal response was observed. The median TTP was 5.11 months. There were two grade 3 adverse events, anemia and prolonged QTc interval, and no grade 4 adverse events. Single-agent enzastaurin was well tolerated but not effective in this heavily pretreated population with MM.

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.

Pomalidomide alone or in combination with low-dose dexamethasone in relapsed and refractory multiple myeloma: a randomized phase 2 study

This multicenter, open-label, randomized phase 2 study assessed the efficacy and safety of pomalidomide (POM) with/without low-dose dexamethasone (LoDEX) in patients with relapsed/refractory multiple myeloma (RRMM). Patients who had received ≥2 prior therapies (including lenalidomide [LEN] and bortezomib [BORT]) and had progressed within 60 days of their last therapy were randomized to POM (4 mg/day on days 1-21 of each 28-day cycle) with/without LoDEX (40 mg/week). The primary end point was progression-free survival (PFS). In total, 221 patients (median 5 prior therapies, range 1-13) received POM+LoDEX (n = 113) or POM (n = 108). With a median follow-up of 14.2 months, median PFS was 4.2 and 2.7 months (hazard ratio = 0.68, P = .003), overall response rates (ORRs) were 33% and 18% (P = .013), median response duration was 8.3 and 10.7 months, and median overall survival (OS) was 16.5 and 13.6 months, respectively. Refractoriness to LEN, or resistance to both LEN and BORT, did not affect outcomes with POM+LoDEX (median PFS 3.8 months for both; ORRs 30% and 31%; and median OS 16 and 13.4 months). Grade 3-4 neutropenia occurred in 41% (POM+LoDEX) and 48% (POM); no grade 3-4 peripheral neuropathy was reported. POM+LoDEX was effective and generally well tolerated and provides an important new treatment option for RRMM patients who have received multiple prior therapies. This trial was registered at www.clinicaltrials.gov as #NCT00833833.

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.

New drugs and novel mechanisms of action in multiple myeloma in 2013: a report from the International Myeloma Working Group (IMWG)

Treatment in medical oncology is gradually shifting from the use of nonspecific chemotherapeutic agents toward an era of novel targeted therapy in which drugs and their combinations target specific aspects of the biology of tumor cells. Multiple myeloma (MM) has become one of the best examples in this regard, reflected in the identification of new pathogenic mechanisms, together with the development of novel drugs that are being explored from the preclinical setting to the early phases of clinical development. We review the biological rationale for the use of the most important new agents for treating MM and summarize their clinical activity in an increasingly busy field. First, we discuss data from already approved and active agents (including second- and third-generation proteasome inhibitors (PIs), immunomodulatory agents and alkylators). Next, we focus on agents with novel mechanisms of action, such as monoclonal antibodies (MoAbs), cell cycle-specific drugs, deacetylase inhibitors, agents acting on the unfolded protein response, signaling transduction pathway inhibitors and kinase inhibitors. Among this plethora of new agents or mechanisms, some are specially promising: anti-CD38 MoAb, such as daratumumab, are the first antibodies with clinical activity as single agents in MM. Moreover, the kinesin spindle protein inhibitor Arry-520 is effective in monotherapy as well as in combination with dexamethasone in heavily pretreated patients. Immunotherapy against MM is also being explored, and probably the most attractive example of this approach is the combination of the anti-CS1 MoAb elotuzumab with lenalidomide and dexamethasone, which has produced exciting results in the relapsed/refractory setting.

Future agents and treatment directions in multiple myeloma

The development of bortezomib and immunomodulatory agents resulted in a revolution in the treatment of multiple myeloma (MM). Moreover, second-generation proteasome inhibitors (carfilzomib) and immunomodulatory agents (pomalidomide) have recently been approved. Nevertheless, the incurability of this disease requires other drugs with different mechanisms of action to either prolong the survival of patients refractory to current therapies, or achieve cure. Active research has been done exploring the pathogenesis of MM and searching for novel, druggable targets. In this regard, some of these novel agents seem promising, such as monoclonal antibodies (anti-CD38 - daratumumab or anti-CS1 - elotuzumab) or the kinesin protein inhibitor Arry-520. Other agents under investigation are kinase inhibitors, signaling pathways inhibitors or deacetylase inhibitors. With so many novel agents under investigation, future therapy in MM will probably involve the combined use of the already approved drugs with some of those newly discovered.

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.

New drugs in multiple myeloma - role of carfilzomib and pomalidomide

Carfilzomib (CFZ), an epoxyketone with specific chymotrypsin-like activity, is a second-generation proteasome inhibitor with significant activity in patients with relapsed and refractory multiple myeloma. On July 20, 2012, the US Food and Drug Administration approved CFZ to treat patients with multiple myeloma who have received at least two prior therapies including bortezomib (BORT) and an immunomodulatory agent and have demonstrated disease progression on or within 60 days of completion of the last therapy. Cytogenetic abnormalities did not appear to have a significant impact on the CFZ activity. Carfilzomib was well tolerated and demonstrated promising efficacy in patients with renal insufficiency. Pomalidomide (POM) (CC-4047) is a novel immunomodulatory derivative (IMID) with a stronger in vitro anti-myeloma effect compared with “older” IMIDs – thalidomide and lenalidomide (LEN). On February 8, 2013, the US Food and Drug Administration approved POM (Pomalyst, Celgene) for the treatment of MM patients who have received at least two prior therapies including LEN and BORT and have demonstrated progression on or within 60 days of completion of the last therapy. Pomalidomide is a novel IMID with significant anti-myeloma activity and manageable toxicity. This compound has shown high efficacy in MM patients who were resistant to prior use of LEN/BORT as well as in patients with a high-risk cytogenetic profile. Carfilzomib and POM have very high efficacy and will be used also in first line therapy in future.

A sensitive and robust HPLC assay with fluorescence detection for the quantification of pomalidomide in human plasma for pharmacokinetic analyses

Pomalidomide is a second generation IMiD (immunomodulatory agent) that has recently been granted approval by the Food and Drug Administration for treatment of relapsed multiple myeloma after prior treatment with two antimyeloma agents, including lenalidomide and bortezomib. A simple and robust HPLC assay with fluorescence detection for pomalidomide over the range of 1-500ng/mL has been developed for application to pharmacokinetic studies in ongoing clinical trials in various other malignancies. A liquid-liquid extraction from human plasma alone or pre-stabilized with 0.1% HCl was performed, using propyl paraben as the internal standard. From plasma either pre-stabilized with 0.1% HCl or not, the assay was shown to be selective, sensitive, accurate, precise, and have minimal matrix effects (<20%). Pomalidomide was stable in plasma through 4 freeze-thaw cycles (<12% change), in plasma at room temperature for up to 2h for samples not pre-stabilized with 0.1% HCl and up to 8h in samples pre-stabilized with 0.1% HCl, 24h post-preparation at 4°C (<2% change), and showed excellent extraction recovery (∼90%). This is the first reported description of the freeze/thaw and plasma stability of pomalidomide in plasma either pre-stabilized with 0.1% HCl or not. The information presented in this manuscript is important when performing pharmacokinetic analyses. The method was used to analyze clinical pharmacokinetics samples obtained after a 5mg oral dose of pomalidomide. This relatively simple HPLC-FL assay allows a broader range of laboratories to measure pomalidomide for application to clinical pharmacokinetics.

Pomalidomide

Pomalidomide (originally CC-4047 or 3-amino-thalidomide) is a derivative of thalidomide that is antiangiogenic and also acts as an immunomodulator. Pomalidomide, as the newest immunomodulatory agent (IMiD), has shown substantial in vitro antiproliferative and proapoptotic effects. In vivo studies have suggested limited cross-resistance between lenalidomide and pomalidomide, and the response of pomalidomide in relapsed and refractory (RR) multiple myeloma (MM) patients, including those who are refractory to both lenalidomide and bortezomib, has induced notable enthusiasm. Several studies have evaluated continuous (2 mg/day) or alternate (5 mg/2 day) dose schedules of pomalidomide, as well as 2 versus 4 mg schedules, and pomalidomide alone versus in combination with dexamethasone or other antimyeloma agents. Since pomalidomide plus low-dose dexamethasone has shown better responses, progression-free and overall survival than high-dose dexamethasone or pomalidomide alone, subsequent trials investigating pomalidomide combination therapy have been initiated. Among these trials combinations with alkylating agents (cyclophosphamide, bendamustin), anthracyclins (pegylated liposomal doxorubicin), proteasome inhibitors (bortezomib, carfilzomib), and various others can be found. Pomalidomide has also been assessed in AL amyloidosis, MPNs (myelofibrosis [MF]), Waldenstrom's macroglobulinemia, solid tumors (sarcoma, lung cancer), or HIV and--for AL amyloidosis and MF--has already proven remarkable activity. Due to its potency, pomalidomide was approved by the US Food and Drug Administration (FDA) for RRMM in 2/2013 and has also been approved by the European Medicines Agency (EMA).

Activity of 129 single-agent drugs in 228 phase I and II clinical trials in multiple myeloma

BACKGROUND

More than 400 preclinical studies report ≥ 1 compound as cytotoxic to multiple myeloma (MM) cells; however, few of these agents became relevant in the clinic. Thus, the utility of such assays in predicting future clinical value is debatable.

PATIENTS AND METHODS

We examined the application of early-phase trial experiences to predict future clinical adoption. We identified 129 drugs explored as single agents in 228 trials involving 7421 patients between 1961 and 2013.

RESULTS

All drugs in common use in MM (melphalan, dexamethasone, prednisone, cyclophosphamide, bendamustine, thalidomide, lenalidomide, pomalidomide, bortezomib, carfilzomib, and doxorubicin) demonstrated a best reported response rate of ≥ 22%. Older agents, including teniposide, fotemustine, paclitaxel, and interferon, also appear active by this criterion; however, if mean response rates from all reported trials for an agent are considered, then only drugs with a mean response rate of 15% partial response are in clinical use.

CONCLUSION

Our analysis suggests that thresholds of 20% for best or 15% for mean response are highly predictive of future clinical success. Below these thresholds, no drug has yet reached regulatory approval or widespread use in the clinic. Thus, this benchmark provides 1 element of the framework for guiding choice of drugs for late-stage clinical testing.

Choosing treatment options for patients with relapsed/refractory multiple myeloma

Multiple myeloma (MM) is a clonal plasma cell disorder that is still incurable using conventional treatments. Over the last decade, advances in front-line therapy have led to an increase in survival, but there are still some doubts in the case of relapsed/refractory disease. We searched the PubMed database for articles on treatment options for patients with relapsed/refractory MM published between 1996 and 2013. These treatments included hematopoietic cell transplantation (HCT), rechallenges using previous chemotherapy regimens, and trials of new regimens. The introduction of new agents such as the immunomodulatory drugs (IMIDs) thalidomide and lenalidomide, and the first-in-its-class proteasome inhibitor bortezomib, has greatly improved clinical outcomes in patients with relapsed/refractory MM, but not all patients respond and those that do may eventually relapse or become refractory to treatment. The challenge is therefore to select the optimal treatment for each patient by balancing efficacy and toxicity. To do this, it is necessary to consider disease-related factors, such as the quality and duration of responses to previous therapies, and the aggressiveness of the relapse, and patient-related factors such as age, comorbidities, performance status, pre-existing toxicities and cytogenetic patterns. The message from the trials reviewed in this article is that the new agents may be used to re-treat relapsed/refractory disease, and that the sequencing of their administration should be modulated on the basis of the various disease and patient-related factors. Moreover, our understanding of the pharmacology and molecular action of the new drugs will contribute to the possibility of developing tailored treatment.

Novel investigational agents for the treatment of scleroderma

INTRODUCTION

The purpose of this article is to highlight novel therapies that are being used in scleroderma (SSc). Therapeutic interventions in SSc generally target at least one of three ongoing biological processes characteristic of the disease: vasculopathy, autoimmunity and tissue fibrosis. Treatment decisions in SSc are determined by the level of disease activity and the degree of specific organ involvement. Traditional therapy has primarily focused on organ-specific management without clear evidence of overall disease modification.

AREAS COVERED

The authors provide a review of a variety of agents, which are already used for other autoimmune diseases, that are now being used to treat active SSc skin or lung disease, including rituximab, tocilizumab and IVIG. Several agents studied in vitro and in animal models of fibrosis have shown promise, including bortezomib, LPA-1 antagonists, anti-CCN2 therapy, anti-IL-13 and thrombin antagonists. The authors also provide details on targeting intracellular molecular pathways and matricellular proteins, which is another novel area of investigation.

EXPERT OPINION

Combination therapy may be necessary to control the complex biological network active in SSc. Most of the current evidence that suggest benefit of these agents is based on small population studies. Ultimately well-designed clinical trials are required to define the role of these agents in treating SSc.

Immunomodulatory effects in a phase II study of lenalidomide combined with cetuximab in refractory KRAS-mutant metastatic colorectal cancer patients

This study assessed the immunomodulatory effects in previously treated KRAS-mutant metastatic colorectal cancer patients participating in a phase II multicenter, open-label clinical trial receiving lenalidomide alone or lenalidomide plus cetuximab. The main findings show the T cell immunostimulatory properties of lenalidomide as the drug induced a decrease in the percentage CD45RA⁺ naïve T cells 3-fold while increasing the percentage HLA-DR⁺ activated T helper cells and percentage total CD45RO⁺ CD8⁺ memory T cytotoxic cells, 2.6- and 2.1-fold respectively (p<0.0001). In addition, lenalidomide decreased the percentage of circulating CD19⁺ B cells 2.6-fold (p<0.0001). Lenalidomide increased a modest, yet significant, 1.4-fold change in the percentage of circulating natural killer cells. Our findings indicate that lenalidomide significantly activates T cells, suggestive of an immunotherapeutic role for this drug in settings of maintenance therapy and tumor immunity. Furthermore, reported for the first time is the effect of lenalidomide in combination with cetuximab on T cell function, including increases in circulating naïve and central memory T cells. In summary, lenalidomide and cetuximab have significant effects on circulating immune cells in patients with colorectal carcinoma.

Trial Registration

ClinicalTrials.gov NCT01032291

Glutamic acid and its derivatives: candidates for rational design of anticancer drugs

Throughout the history of human civilizations, cancer has been a major health problem. Its treatment has been interesting but challenging to scientists. Glutamic acid and its derivative glutamine are known to play interesting roles in cancer genesis, hence, it was realized that structurally variant glutamic acid derivatives may be designed and developed and, might be having antagonistic effects on cancer. The present article describes the state-of-art of glutamic acid and its derivatives as anticancer agents. Attempts have been made to explore the effectivity of drug-delivery systems based on glutamic acid for the delivery of anticancer drugs. Moreover, efforts have also been made to discuss the mechanism of action of glutamic acid derivatives as anticancer agents, clinical applications of glutamic acid derivatives, as well as recent developments and future perspectives of glutamic acid drug development have also been discussed.

Pomalidomide: the new immunomodulatory agent for the treatment of multiple myeloma

In this report, we provide a comprehensive review on the preclinical and clinical investigations conducted in development of the next-generation immunomodulatory drug (IMiD) pomalidomide for the treatment of relapsed/refractory multiple myeloma (MM). We consulted PubMed, MEDLINE, ASH, ASCO annual symposium abstracts and http://clinicaltrials.gov/ for the purpose of this literature review. Twenty-six preclinical and 11 clinical studies were examined. These studies delineate the mechanisms of action of pomalidomide and attest to the robust clinical activity in relapsed/refractory MM. MM is the second most common hematological malignancy in the US. Despite availability of several therapeutic agents, MM remains incurable. Thus, the development of new therapies remains a priority. Pomalidomide is the newest member of the IMiDs class of drugs, and in preclinical and clinical investigations, it has demonstrated an improved efficacy and toxicity profile in comparison to its sister compounds, lenalidomide and thalidomide. Importantly, recent clinical studies have demonstrated its activity in relapsed or refractory myeloma, particularly in lenalidomide and bortezomib-refractory patients. Thus, the addition of pomalidomide to the anti-myeloma armamentarium is widely anticipated to have a significant impact on the overall clinical outcome of advanced stage relapsed and refractory MM patients.