Vinflunine: drug safety evaluation of this novel synthetic vinca alkaloid

INTRODUCTION: Vinca alkaloid agents have been widely used in several different types of malignancies. However, cancer cells, ultimately, develop resistance to these agents. Therefore, the development of new agents with improved efficacy is warranted. Recently, a new synthetic vinca alkaloid, vinflunine, was developed through the addition of two fluor molecules by superacidic chemistry. AREAS COVERED: The authors describe the development of the new vinca alkaloid vinflunine from preclinical studies to the late-stage clinical trials, highlighting the most important clinical and safety data of vinflunine. In vitro and in vivo studies have shown a superior efficacy of vinflunine over other vinca alkaloids and with an improved safety profile. Early clinical trials have demonstrated a significant activity of vinflunine against different malignancies. Phase III trials showed that vinflunine increases survival in patients with advanced transitional cell carcinoma of the urothelium (TCCU) tract treated in the second-line and is as effective as docetaxel in second-line NSCLC. EXPERT OPINION: Vinflunine is currently approved in Europe for the treatment of second-line TCCU and is currently being developed in other malignancies. It has been shown to have predictable and manageable adverse effects, such as neutropenia, anemia, constipation and fatigue.     

Vinflunine for the treatment of breast cancer

Introduction: Breast cancer is the most frequently diagnosed cancer and the highest cause of cancer mortality in females worldwide. The development of drugs improving overall survival in late-stage metastatic breast cancer remains a challenge.

Vinflunine is the most recently developed drug in the vinca alkaloid class. Its arrival has been eagerly awaited for treatment of solid tumors, and in particular, for metastatic breast cancer.

Areas covered: The pharmacological features of vinflunine are described. Its clinical development as monotherapy or in combination in metastatic breast cancer is detailed. A literature search on the topic was conducted through PubMed, clinical trials and the proceedings of the main cancer congresses.

Expert opinion: The overall results from phase III studies, and in particular those that combined vinflunine with capecitabine, have been less favorable. The combination’s effectiveness was at best moderate compared with other drugs which also target metastatic breast cancer, and complicated by significant hematological and gastrointestinal adverse effects. Its use in advanced metastatic breast cancer cannot currently be recommended.     

Vinflunine for the treatment of non-small cell lung cancer

Introduction: Vinflunine belongs to the class of vinca alkaloids and acts by disrupting the microtubule dynamics during cell cycle; this agent is currently available for previously treated advanced transitional cell carcinoma in Europe. The aim of this invited review is to evaluate the potential role of vinflunine for the treatment of non-small cell lung cancer (NSCLC).

Areas covered: The potential role of vinflunine in NSCLC is discussed on the basis of the available data, including full papers and meeting abstracts. Relevant preclinical studies describing the pharmacological properties of vinflunine are also included. The review also summarizes clinical studies, including phase I trials involving NSCLC among other tumors as well as phase II/III trials specifically addressing this malignancy. Additionally, the safety profile and the current regulatory status of vinflunine is discussed.

Expert opinion: Vinflunine is active as single agent and as part of platinum-based combinations in NSCLC. It results non-inferior to docetaxel in a randomized phase III trial including previously treated NSCLC patients; additionally, its safety profile is generally considered manageable. Ultimately, further studies are needed to confirm the role of vinflunine in NSCLC, in consideration of the evolving evidence regarding targeted therapies and immune check-point inhibitors.     

Vinflunine as second-line treatment in platin-resistant metastatic urothelial carcinoma: a review

The novel third-generation bifluorinated semisynthetic vinca alkaloid, vinflunine, is a microtubule inhibitor that shows superior antitumor activity and a favorable safety profile compared with other vinca alkaloids. The main antineoplastic effects of vinflunine arise from its interaction with tubulin, the major component of microtubules in mitotic spindles. Vinflunine is known to have low affinity for tubulin, high intracellular accumulation, and important effects on microtubule dynamics. It has been shown to have activity against transitional cell carcinoma of the urothelial tract. Vinflunine was investigated in a randomized phase III clinical trial comparing vinflunine and best supportive care versus best supportive care alone in patients with advanced transitional cell carcinoma of the urothelial tract, who were progressive after first-line platinum-containing therapy. At an acceptable safety profile without cumulative toxicity, second-line treatment with vinflunine has shown a survival advantage and has therefore been approved in 2009 for this indication. This review gives a brief outline on vinflunine as a second-line treatment for platin-resistant advanced urothelial carcinoma; it describes pharmacology, efficacy studies, tolerance, and side effects and briefly discusses future clinical perspectives.     

Vinflunine: a fluorinated vinca alkaloid for bladder cancer therapy

Vinflunine is a novel third-generation bifluorinated semisynthetic vinca alkaloid that has been shown to have activity against a variety of solid tumor types including advanced transitional cell carcinoma of the urothelium. In contrast to other vinca alkaloids, vinflunine shows superior antitumor activity and an excellent safety profile. Vinflunine interacts with tubulin and has a lower affinity to tubulin; it has a high intracellular accumulation rate and therefore significant effects on microtubule dynamics. A large, phase III trial comparing vinflunine with best supportive care versus best supportive care alone showed an improvement in overall survival in the vinflunine arm in preplanned secondary analyses. In addition, the drug has shown a moderate adverse event profile in the phase II and III trials. In September 2009, vinflunine was approved as a second-line treatment for patients with urothelial carcinoma resistant to first-line platinum-containing chemotherapy by the European Medicines Agency.     

Current investigational drugs in psoriasis

Introduction : The advent of biologic therapies has revolutionized the treatment of psoriasis. Increased understanding of immunogenetic pathways has allowed for the development of more selective targeted biologic therapies. Multiple new treatments are currently in development for the treatment of psoriasis. Preliminary data for many of these agents, particularly with regard to agents targeting the IL-23/Th17 pathway, are promising. Proven long-term safety, however, is an absolute necessity with newly developed drugs, and should, therefore, still be considered second-line agents to current established treatments with long-term safety data.

Areas covered : This review details the mechanisms of action of drugs currently in development or in clinical trials for the treatment of psoriasis, using clinical trial registries and associated publications. Readers will gain a comprehensive overview about the mechanism of action of emerging treatments targeting various immune pathways deeply involved in psoriasis. Pathogenesis, clinical efficacy and safety data for these treatments are discussed where available.

Expert opinion : Psoriasis remains a heavily undertreated systemic immune-mediated disease despite increased understanding of immunopathogenesis of the disease and advent of a multitude of novel therapeutic agents with potentially improved bioavailability and safety profiles. Limitations, however, remain in the realm of topical agents for treatment of mild to moderate psoriasis, which has seen little progress over the years. A concerted effort will need to be made among researchers, clinicians and patient advocacy groups to ensure new therapeutic agents are developed and gain proper exposure.     

Pemetrexed in advanced non-small-cell lung cancer

Importance of the field: Current therapeutic options for advanced non-small-cell lung cancer (NSCLC) yield relatively modest improvements in survival leading to an ongoing search for new active treatment agents. In the past decade, pemetrexed has had an increasingly established role in the treatment of advanced NSCLC in both first- and second-line settings.

Areas covered in this review: Currently available published data on mechanism of action, pharmacokinetics, safety and efficacy of pemetrexed in the treatment of advanced NSCLC are described. Peer-reviewed publications on the development of pemetrexed and its clinical use in NSCLC were reviewed (1995 – 2009).

What the reader will gain: Pemetrexed is a multitargeted antifolate cytotoxic agent. Key Phase II and Phase III trials are described that have shown pemetrexed's efficacy in both the first- and second-line treatment of advanced NSCLC. The efficacy of pemetrexed seems to vary between squamous and nonsquamous histologies. Possible reasons for this are explored. Additionally, the potential role of pemetrexed in maintenance therapy is discussed.

Take home message: Pemetrexed is an effective treatment for advanced NSCLC, with an overall favorable toxicity profile. There is growing evidence that, in patients treated with pemetrexed, nonsquamous tumors have improved outcomes compared to squamous cell tumors. Pemetrexed may also have a role in maintenance therapy for NSCLC.     

Emerging role of the histone deacetylase inhibitor romidepsin in hematologic malignancies

Importance of the field: Histone acetylation plays a crucial role in chromatin modification and the regulation of gene expression. Histone deacetylase inhibitors (HDACi) are a novel class of antitumor agents with pleiotropic effects; they are under active clinical investigation. The HDACi romidepsin is being evaluated in a variety of tumors and was recently approved for the treatment of cutaneous T-cell lymphomas (CTCL).

Areas covered in this review: This review focuses on the findings from early Phase trials involving romidepsin, and the Phase II trial results that led to the approval of romidepsin in CTCL.

What the reader will gain: Mechanisms of action of HDACi, including romidepsin, are described in this review and the pharmacodynamic and pharmacokinetic properties of romidepsin are summarized. The efficacy and safety profile of romidepsin in clinical trials in T-cell lymphoma is reviewed, and emerging data on single-agent and combination strategies in myeloid and B-lymphoid malignancies is outlined.

Take home message: Romidepsin has significant activity and an acceptable safety profile in CTCL and peripheral T-cell lymphomas. Its use in rationally designed combination approaches is under active investigation in B-lymphoid malignancies.     

Ramucirumab for the treatment of gastric cancers,colorectal adenocarcinomas,and other gastrointestinal malignancies

Introduction: The use of antiangiogenic strategy in the treatment of advanced colorectal cancers has been largely evidence-based. More recently, novel vascular endothelial growth factor receptor (VEGFR) inhibitors have been studied in other gastrointestinal diseases. Ramucirumab, a recombinant monoclonal antibody that binds to VEGFR2 extracellular domain with a much greater affinity compared to its natural ligand, showed second-line effectiveness for patients with gastric or colorectal carcinomas.

Areas covered: We perform a narrative literature review. The aims of our work are to recall the current evidence of its efficacy in the treatment of gastric, hepatocellular and colorectal cancers and to present the ongoing studies enrolling gastrointestinal cancer patients in which ramucirumab is being tested.

Expert commentary: The landscape of angiogenesis-inhibition for the treatment of GI malignancies is rapidly evolving. The results of the REGARD and RAINBOW trials renewed the interest for antiangiogenic agents in gastric cancer and determined a swift change in the treating paradigm for this disease. Accordingly, ramucirumab was shown to be effective in pretreated colorectal cancer patients and it is being tested in other gastrointestinal malignancies.     

Clinical and economic comparison of epoetin alfa and darbepoetin alfa

SUMMARY

Background: The pharmacoeconomics of erythropoietic therapy for the treatment of anemia is receiving renewed attention due to the current availability of two agents. Epoetin alfa has been the standard of therapy for patients with renal disease and cancer-related anemia for more than a decade. Darbepoetin alfa, an alternative agent, is now approved for anemia resulting from renal disease and cancer chemotherapy.

Methodology: Although direct comparative trials have not been performed with these agents, information published in the last several years regarding their clinical efficacy, safety, and dosing is sufficient, in most cases, to compare costs. With the disclaimer that any efficacy comparison of competing products using published reports has certain limitations, a cost-minimization approach from a provider's perspective was conducted.

Results:To provide background for the economic evaluation, pharmacokinetic and pharmacodynamic data for these two agents are discussed. Recent clinical trials in the nephrology and oncology therapeutic areas are summarized, highlighting study designs, dosing regimens, patient entry criteria, study endpoints, and published results. Cost data, based on average wholesale prices (AWP) in 2003, are compared and calculated from available clinical data with an emphasis on efficacy.

Conclusion: These evaluations largely conclude that epoetin alfa is the better pharmacoeconomic value of the two currently available erythropoietic agents.     

The potential of neurotrophic tyrosine kinase (NTRK) inhibitors for treating lung cancer

Introduction: Molecular alterations in neurotrophic tyrosine kinase (NTRK) genes have been identified in several solid tumors including lung cancer. Pre-clinical and clinical evidence suggested their potential role as oncogenic drivers and predictive biomarkers for targeted inhibition, leading to the clinical development of a new class of compounds blocking the NTRK molecular pathway, which are currently undner early clinical investigation.

Area covered: This review describes the biology of the NTRK pathway and its molecular alterations in lung cancer. It focuses on the pre-clinical and clinical development of emerging NTRK inhibitors, which have shown very promising activity in early phase I studies.

Expert opinion: Among the several NTRK-inhibitors, entrectinib and LOXO-101 are those in more advanced stage of clinical development. Both agents have shown encouraging activity along with a tolerable safety profile in patients with different solid tumors harboring NTRK-fusions, emerging as new promising therapeutic options for molecularly selected patients with advanced Trk-driven lung cancers. Results from ongoing phase II basket trials are eagerly awaited.     

The expanding role of nilotinib in chronic myeloid leukemia

Importance of the field: Several therapeutic options, including tyrosine kinase inhibitors, exist for the treatment of patients with Philadelphia chromosome (Ph)-positive chronic myeloid leukemia (CML). Despite impressive results, there is room for improvement for those patients who are either resistant or intolerant to imatinib.

Areas covered in this review: An overview is given on the clinical results with nilotinib, a rationally designed second-generation tyrosine kinase inhibitor, as first- and second-line therapy in patients with Ph-positive CML. Important factors in predicting resistance to nilotinib and guiding therapeutic decisions are addressed.

What the reader will gain: Knowledge on the clinical efficacy and safety of nilotinib after imatinib failure and as first-line treatment. Point mutations in the kinase domain (KD) of BCR-ABL1 are important determinants of clinical sensitivity to currently available tyrosine kinase inhibitors, including nilotinib. Information on specific BCR-ABL1 KD mutations and safety profiles assist in therapeutic decision making.

Take home message: Nilotinib is a highly effective and well-tolerated therapeutic option in patients with Ph-positive CML after imatinib failure. Early evidence demonstrating increased efficacy has allowed expanding nilotinib to previously untreated patients in chronic phase. Insights into mechanisms of resistance to tyrosine kinase inhibitors and predictive factors for response will allow for a more individualized use of these agents.     

Vinflunine: clinical perspectives of an emerging anticancer agent

Background: Vinflunine is a novel second generation of Vinca alkaloid. The binding of vinflunine to tubulin and subsequent cellular arrest in mitosis is the core mechanism of this antineoplastic agent. In addition, its potential vascular-disrupting and antiangiogenic activities uphold further clinical development of this compound. Objective: To review and summarise the pharmacological and latest clinical data, and discuss the impact of vinflunine on current treatment regimens. Methods: A review of published literature and conference abstracts for results of previous preclinical and latest clinical studies in all cancer types was performed. Results/conclusions: Noteworthy results from Phase II studies for treatment of non-small cell lung cancer (NSCLC), breast cancer and bladder cancer supported Phase III studies. One of the Phase III studies for treatment of advanced NSCLC showed important results. Encouraging results of combination use of vinflunine and other biologic agents also opened areas to investigate its synergistic or auxiliary role to existing therapies.     

Novel integrase inhibitors for HIV

Importance of the field: Integrase inhibitors are the newest class of antiretroviral agents developed to treat HIV-1 infection. Raltegravir (RAL), the only integrase inhibitor (INI) currently approved for the treatment of HIV-infected patients, has proven to be a potent and well-tolerated antiretroviral (ARV) agent. It is currently approved and used for the treatment of both ARV-experienced and ARV-naive patients. Nevertheless, the relatively low genetic barrier for resistance of RAL encourages the search for new INIs with different mechanisms of actions and resistance profiles.

Areas covered in this review: Here we review the data available about INI that are currently being tested in clinical trials or are in preclinical development: elvitegravir (EVG), S/GSK1349572, S/GSK1265744 and LEDGINs. We focus on their clinical efficacy, pharmacokinetic, safety and resistance profiles.

What the reader will gain: Up-to-date overview on the currently available, clinically relevant INIs and promising preclinical inhibitors at all phases of development.

Take home message: Integrase inhibitors represent the newest therapeutic class available to treat HIV-1 infection. There are a variety of compounds either available in the clinic (RAL), advancing to Phase III trials (EVG), or in earlier phases of development. Taken together, this class offers new treatment options for the HIV-infected individual.     

Prospects for MEK inhibitors for treating cancer

Introduction: The MAPK pathway is a signaling network that plays a key role in many normal cellular processes and in a large number of human malignancies. One of its effectors, MEK, is essential for the carcinogenesis of different tumors. In recent years, several drugs able to inhibit MEK have been assessed in clinical trials. Trametinib has recently become the first MEK inhibitor licensed for cancer treatment (advanced melanoma).

Areas covered: We comprehensively review the safety and clinical efficacy of the family of MEK inhibitors, either alone or in combination with other drugs. We discuss data ranging from the Phase III trial of trametinib in melanoma to the most recent drugs with early signs of antitumor activity. In addition, we explain the reasons for the unsuccessful results of the early trials with MEK inhibitors and provide a view of their role in cancer treatment in forthcoming years.

Expert opinion: MEK inhibitors are a potentially safe and active treatment option for the treatment of many human malignancies. The information provided by a large series of studies currently ongoing will be very valuable in order to optimize their use. Adequate selection of patients is crucial for achieving successful results with these compounds.     

Update on immunomodulatory drugs (IMiDs) in hematologic and solid malignancies

Introduction: Thalidomide and its analogs [small molecule immunomodulatory drugs (IMiDs®)] are among the most successful new therapeutic agents of recent years. Thalidomide is now an integral part of multiple myeloma (MM) therapy. Lenalidomide has been approved for the treatment of patients with relapsed MM and 5q-myelodysplastic syndromes (MDS). Currently, more than 400 clinical trials are evaluating the activity of lenalidomide, alone or in combination with other conventional or novel therapies, in newly diagnosed MM and 5q-MDS. Based on their broad range of actions within the tumor microenvironment, IMiDs are currently also evaluated in a wide variety of additional hematologic and solid malignancies.

Areas covered: This paper reviews the historic development of thalidomide and its derivatives and presents novel insights into their mode of action. Moreover, it discusses up-to-date clinical trials investigating IMiDs and potential future research and therapeutic perspectives in MM and other malignancies.

Expert opinion: Although IMiDs have emerged as powerful agents for the treatment of hematologic and solid tumors, more preclinical and clinical studies are urgently needed both to increase our knowledge of their mechanisms of action, and to optimize their clinical use, in order to further improve the patient's quality of life and survival.     

An evaluation of fulvestrant for the treatment of metastatic breast cancer

ABSTRACT

Introduction: Fulvestrant is currently the only selective estrogen receptor degrader (SERD) that is approved for clinical use in estrogen receptor (ER) positive advanced breast cancer (ABC). The drug is approved as single-agent therapy in the first and second-line setting of metastatic ER-positive breast cancer.

Areas covered: In this review, the authors review the preclinical studies that were pivotal in the development of fulvestrant, the pharmacologic properties of the drug, and the key clinical trials that resulted in its approval for clinical use. The authors discuss mechanisms of endocrine resistance and potential targets for endocrine refractory disease while highlighting ongoing studies that assess fulvestrant use with novel agents.

Expert opinion: While fulvestrant has limited use in the first-line setting in advanced breast cancer, it is most frequently used in the second line after progression with aromatase inhibitors. The combination of fulvestrant with CDK4/6 inhibitors has shown a clear benefit over monotherapy in patients who progress on prior endocrine therapy. Further study is necessary to assess if patient outcomes can be enhanced by optimizing the sequence of endocrine therapies, targeting resistance pathways with novel agents, and development of new agents in the SERD class.     

An overview of early drug development for endometriosis

Introduction: Endometriosis is an estrogen-dependent chronic disease of women of fertile age requiring chronic therapy. Although available drugs have good efficacy and safety profiles, some patients experience partial or no improvement of pain with conventional treatment and recurrence of symptoms after discontinuation of the therapies. For these reasons, many new compounds are currently under investigation for the treatment of endometriosis.

Areas covered: This review offers the reader a complete and updated overview on emerging therapies for the treatment of endometriosis. The authors describe, in detail, the laboratory and clinical studies on these therapies and highlight the potential advantages and limitations associated with the administration of these new agents.

Expert opinion: Gonadotropin-releasing hormone antagonists are the most intriguing emerging agents for the treatment of patients with endometriosis. It should be noted that while there are a number of drugs under investigation, a large majority of these new compounds have only been investigated in laboratory studies with more extensive research required to better elucidate their efficacy and safety profiles.     

Patupilone in cancer treatment

Importance of the field: Since the introduction of taxane-based chemotherapy for advanced solid tumors in the 1990s, the median overall survival of patients with metastatic breast cancer increased from 2 years to almost 5 years. Similarly, the 5-year overall survival for ovarian cancer has increased from 30% to more than 40%.

Areas covered in this review: Patupilone is a novel cytotoxic compound, with similar microtubule-binding and apoptotic properties of taxanes and is active in taxane-resistant cell lines. Over 1200 patients have been treated with patupilone in Phase I – III clinical trials and a wealth of knowledge has accumulated about this compound. This review discusses current pharmacology and data from clinical trials with patupilone from the last seven years.

What the reader will gain: We present a comprehensive summary of data from Phase II and III trials, as well as an overview of currently accruing trials.

Take home message: Although patupilone has not demonstrated superiority over pegylated liposomal doxorubicin in a large Phase III trial in relapsed or refractory ovarian cancer, its evaluation is continuing in a range of other malignancies, especially in primary or secondary tumors of the CNS.