Randomized Multicenter Phase II Study of Larotaxel (XRP9881) in Combination with Cisplatin or Gemcitabine as First-Line Chemotherapy in Nonirradiable Stage IIIB or Stage IV Non-small Cell Lung Cancer

HPLC separation, synthesis, isolation and characterization of process related and degradation impurities in larotaxel including method development and validation

In the synthesis of larotaxel, a new-generation toxoid, eleven related impurities were detected. In this study, Impurity-I, II, III, IV, VII, IX, X and XI were synthesized, and Impurity-VI, VIII were isolated with the help of preparative high-performance liquid chromatography (HPLC). The structures of all impurities were characterized using high-resolution mass spectrometry (HRMS) and nuclear magnetic resonance (NMR) spectral data, and the possible origins of them were explained. Furthermore, a sensitive and accurate HPLC method was developed for the determination of larotaxel and its eleven impurities. The method was validated to fulfill the requirements of the International Conference on Harmonisation (ICH) guidelines, including specificity, sensitivity, precision, accuracy, linearity, and robustness. The validated method can be applied for routine quality control analysis of larotaxel.

The Progress of the Anticancer Agents Related to the Microtubules Target

Anticancer drugs based on the microtubules target are potent mitotic spindle poison agents, which interact directly with the microtubules, and were classified as microtubule-stabilizing agents and microtubule-destabilizing agents. Researchers have worked tremendously towards the improvements of anticancer drugs, in terms of improving the efficacy, solubility and reducing the side effects, which brought about advancement in chemotherapy. In this review, we focused on describing the discovery, structures and functions of the microtubules as well as the progress of anticancer agents related to the microtubules, which will provide adequate references for researchers.

[Spectrometric analyses of larotaxel and larotaxel liposomes quantification by high performance liquid chromatography]

OBJECTIVE

Larotaxel is a new chemical structure drug, which has not been marketed worldwide. Accordingly, the standard identification and quantification methods for larotaxel remain unclear. The spectrometric analyses were performed for verifying weight molecular formula, molecular weight and chemical structure of larotaxel. Besides, a quantification method was developed for measuring larotaxel in the liposomes.

METHODS

The molecular formula, molecular weight and chemical structure of larotaxel were studied by using mass spectrometry (MS), infra-red (IR), nuclear magnetic resonance (NMR) and ultraviolet-visible (UV-vis) spectrometric techniques. The absorption wavelength of larotaxel was investigated by UV-vis spectrophotometry full-wavelength scanning. Besides, a quantification method was developed by high performance liquid chromatography (HPLC), and then validated by measuring the encapsulation efficacy of larotaxel liposomes.

RESULTS

The four spectral characteristics of larotaxel were revealed and the corresponding standard spectra were defined. It was confirmed that larotaxel had the structure of tricyclic diterpenoids, with the molecular formula of C45H53NO14, the molecular weight of 831.900 1, and the maximum absorption wavelength of 230 nm. The quantitative method of larotaxel was established by using HPLC with a reversed phase C18 column (5 μm, 250 mm×4.6 mm), a mobile phase of acetonitrile-water (75:25, volume/volume), and a detection wavelength of 230 nm. The validation study exhibited that the established HPLC method was stable, and had a high recovery and precision in the quantitative measurement of larotaxel in liposomes. In addition, a new kind of larotaxel liposomes was also successfully prepared. The particle size of the liposomes was about 105 nm, with an even size distribution. And the encapsulation efficiency of larotaxel in the liposomes was above 80%.

CONCLUSION

The present study offers reference standard spectra of larotaxel, including MS, IR, NMR, and UV-vis, and confirms the molecular formula, molecular weight and chemical structure of larotaxel. Besides, the study develops a rapid HPLC method for quality control of larotaxel liposomes.

Degradation kinetics of larotaxel and identification of its degradation products in alkaline condition

Larotaxel, a new taxane compound prepared by partial synthesis from 10-deacetyl baccatin III, is active against tumors. In this research, a selective LC-MS method was developed and validated for the study of degradation kinetics of larotaxel, which was carried out in aqueous solutions with different pH (1.5, 3.0, 5.0, 6.5, 7.4, 9.0, 10 and 11.0) and temperature (0, 25, 37 and 45 °C). The linear range was 0.5-25 μg/mL, the intra- and inter-day precisions were less than 7.0%, and accuracy ranged from 97.4-104.5% for each analyte. The observed rate obtained by measuring the remaining intact larotaxel was shown to follow first-order kinetics. The activation energies for degradation were 126.7 and 87.01 kJ/mol at pH 1.5 and 11, respectively. Although larotaxel was stable in pH 5, 6.5 and 7.4 buffers at 37 °C for 24 h during our study, increasing or decreasing the pH of the solutions would decrease its stabilities. Moreover, three main degradation products in alkaline condition were separated by HPLC and identified by Q-TOF-MS. The three degradation products were confirmed as 10-deacetyl larotaxel, 7, 8-cyclopropyl baccatin Ⅲ and 10-deacetyl-7, 8-cyclopropyl baccatin Ⅲ.

Pharmacokinetics and tissue distribution of larotaxel in rats: comparison of larotaxel solution with larotaxel-loaded folate receptor-targeting amphiphilic copolymer-modified liposomes

1. The aim of this study was to compare the pharmacokinetics (PKs) and tissue distribution of larotaxel (LTX) solution with a newly developed formulation called LTX-loaded folate-poly (PEG-cyanoacrylate-co-cholesteryl cyanoacrylate) (FA-PEG-PCHL)-modified liposomes in rats. 2. An ultra-performance liquid chromatography-tandem mass spectrometry method has been developed and validated for the determination of LTX in rat plasma and tissues to investigate the influence of FA-PEG-PCHL-modified lipid carrier on LTX PKs and tissue distribution. 3. The PK study result showed significantly higher area under the concentration-time curve (97.2%, **p < 0.01), slower clearance (49.2%, **p < 0.01) and lower volume of distribution (42.5%, **p < 0.01) in rats following intravenous administration of modified liposomes. The biodistribution results exhibited significantly lower uptake of LTX-loaded modified liposomes in heart (20.4%, **p < 0.01), lung (8.33%, **p < 0.01), muscle (13.4%, *p < 0.05) and spleen (15.0%, **p < 0.01) among all sampled tissues, indicating that the modified lipid carriers may avoid the trapping by the reticuloendothelial system and the modified liposomes may reduce toxicity in cardiovascular system compared to LTX solution. Moreover, markedly higher concentrations of LTX in the kidney (100%, **p < 0.01) were found in LTX-loaded modified liposome treated rats and could be explained by the high folate receptor level in kidney. 4. These results indicated that the FA-PEG-PCHL-modified liposome could be an effective parenteral carrier for the delivery of LTX in cancer treatment.

Chemotherapy for advanced non-small cell lung cancer in the elderly population

BACKGROUND

Approximately 50% of patients with newly diagnosed non-small cell lung cancer (NSCLC) are over 70 years of age at diagnosis. Despite this fact, these patients are underrepresented in randomized controlled trials (RCTs). As a consequence, the most appropriate regimens for these patients are controversial, and the role of single-agent or combination therapy is unclear. In this setting, a critical systematic review of RCTs in this group of patients is warranted.

OBJECTIVES

To assess the effectiveness and safety of different cytotoxic chemotherapy regimens for previously untreated elderly patients with advanced (stage IIIB and IV) NSCLC. To also assess the impact of cytotoxic chemotherapy on quality of life.

SEARCH METHODS

We searched the following electronic databases: Cochrane Central Register of Controlled Trials (CENTRAL; 2014, Issue 10), MEDLINE (1966 to 31 October 2014), EMBASE (1974 to 31 October 2014), and Latin American Caribbean Health Sciences Literature (LILACS) (1982 to 31 October 2014). In addition, we handsearched the proceedings of major conferences, reference lists from relevant resources, and the ClinicalTrial.gov database.

SELECTION CRITERIA

We included only RCTs that compared non-platinum single-agent therapy versus non-platinum combination therapy, or non-platinum therapy versus platinum combination therapy in patients over 70 years of age with advanced NSCLC. We allowed inclusion of RCTs specifically designed for the elderly population and those designed for elderly subgroup analyses.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed search results, and a third review author resolved disagreements. We analyzed the following endpoints: overall survival (OS), one-year survival rate (1yOS), progression-free survival (PFS), objective response rate (ORR), major adverse events, and quality of life (QoL).

MAIN RESULTS

We included 51 trials in the review: non-platinum single-agent therapy versus non-platinum combination therapy (seven trials) and non-platinum combination therapy versus platinum combination therapy (44 trials). Non-platinum single-agent versus non-platinum combination therapy Low-quality evidence suggests that these treatments have similar effects on overall survival (hazard ratio (HR) 0.92, 95% confidence interval (CI) 0.72 to 1.17; participants = 1062; five RCTs), 1yOS (risk ratio (RR) 0.88, 95% CI 0.73 to 1.07; participants = 992; four RCTs), and PFS (HR 0.94, 95% CI 0.83 to 1.07; participants = 942; four RCTs). Non-platinum combination therapy may better improve ORR compared with non-platinum single-agent therapy (RR 1.79, 95% CI 1.41 to 2.26; participants = 1014; five RCTs; low-quality evidence).Differences in effects on major adverse events between treatment groups were as follows: anemia: RR 1.10, 95% 0.53 to 2.31; participants = 983; four RCTs; very low-quality evidence; neutropenia: RR 1.26, 95% CI 0.96 to 1.65; participants = 983; four RCTs; low-quality evidence; and thrombocytopenia: RR 1.45, 95% CI 0.73 to 2.89; participants = 914; three RCTs; very low-quality evidence. Only two RCTs assessed quality of life; however, we were unable to perform a meta-analysis because of the paucity of available data. Non-platinum therapy versus platinum combination therapy Platinum combination therapy probably improves OS (HR 0.76, 95% CI 0.69 to 0.85; participants = 1705; 13 RCTs; moderate-quality evidence), 1yOS (RR 0.89, 95% CI 0.82 to 0.96; participants = 813; 13 RCTs; moderate-quality evidence), and ORR (RR 1.57, 95% CI 1.32 to 1.85; participants = 1432; 11 RCTs; moderate-quality evidence) compared with non-platinum therapies. Platinum combination therapy may also improve PFS, although our confidence in this finding is limited because the quality of evidence was low (HR 0.76, 95% CI 0.61 to 0.93; participants = 1273; nine RCTs).Effects on major adverse events between treatment groups were as follows: anemia: RR 2.53, 95% CI 1.70 to 3.76; participants = 1437; 11 RCTs; low-quality evidence; thrombocytopenia: RR 3.59, 95% CI 2.22 to 5.82; participants = 1260; nine RCTs; low-quality evidence; fatigue: RR 1.56, 95% CI 1.02 to 2.38; participants = 1150; seven RCTs; emesis: RR 3.64, 95% CI 1.82 to 7.29; participants = 1193; eight RCTs; and peripheral neuropathy: RR 7.02, 95% CI 2.42 to 20.41; participants = 776; five RCTs; low-quality evidence. Only five RCTs assessed QoL; however, we were unable to perform a meta-analysis because of the paucity of available data.

AUTHORS' CONCLUSIONS

In people over the age of 70 with advanced NSCLC who do not have significant co-morbidities, increased survival with platinum combination therapy needs to be balanced against higher risk of major adverse events when compared with non-platinum therapy. For people who are not suitable candidates for platinum treatment, we have found low-quality evidence suggesting that non-platinum combination and single-agent therapy regimens have similar effects on survival. We are uncertain as to the comparability of their adverse event profiles. Additional evidence on quality of life gathered from additional studies is needed to help inform decision making.

Tubulin: an example of targeted chemotherapy

Anticancer drugs directed against the microtubule, including taxanes and vinca alkaloids, have been the backbone of many chemotherapy regimes for decades. These drugs have, however, significant limitations, which have prompted the development of novel microtubule targeting agents (MTAs). This article will discuss MTAs for anticancer therapies and recent debates regarding their mechanisms of action. Furthermore, the limitations of taxanes, including hypersensitivity reactions, neurotoxicity, drug resistance and lack of validated biomarkers to guide therapy will be discussed, all of which have driven the development of novel agents. The mechanisms of action and drug development of new generations of MTAs will also be outlined. Agents demonstrating utility in Phase III clinical trials, including eribulin, ixabepilone, cabazitaxel and trastuzumab-DM1 will be highlighted, as well as novel agents currently in development and future directions for MTAs.

Update on taxane development: new analogs and new formulations

The taxanes (paclitaxel and docetaxel) represent an important class of antineoplastic agents that interfere with microtubule function leading to altered mitosis and cellular death. Paclitaxel (Taxol(®)) was originally extracted from a yew tree (Taxus spp., Taxaceae) a small slow-growing evergreen, coniferous tree. Due to the initial scarcity of paclitaxel, docetaxel (Taxotere(®)) a semisynthetic analog of paclitaxel produced from the needles of European yew tree, Taxus baccata was developed. Docetaxel differs from paclitaxel in two positions in its chemical structure and this small alteration makes it more water soluble. Today, paclitaxel and docetaxel are widely prescribed antineoplastic agents for a broad range of malignancies including lung cancer, breast cancer, prostate cancer, Kaposi's sarcoma, squamous cell carcinoma of the head and neck, gastric cancer, esophageal cancer, bladder cancer, and other carcinomas. Although very active clinically, paclitaxel and docetaxel have several clinical problems including poor drug solubility, serious dose-limiting toxicities such as myelosuppression, peripheral sensory neuropathy, allergic reactions, and eventual development of drug resistance. A number of these side effects have been associated with the solvents used for dilution of these antineoplastic agents: Cremophor EL for paclitaxel and polysorbate 80 for docetaxel. In addition, reports have linked these solvents to the alterations in paclitaxel and docetaxel pharmacokinetic profiles. In this review, we provide preclinical and clinical data on several novel taxanes formulations and analogs which are currently US Food and Drug Administration (FDA)-approved or in clinical development in various solid tumor malignancies. Of the new taxanes nab-paclitaxel and cabazitaxel have enjoyed clinical success and are FDA-approved; while many of the other compounds described in this review are unlikely to be further developed for clinical use in daily practice. Furthermore, the successful clinical emergence of novel nontaxane microtubule-targeting chemotherapy agents such as epothilones and eribulin is liable to further restrict the development of novel taxanes.

Risk of venous thromboembolism in patients with cancer treated with Cisplatin: a systematic review and meta-analysis

PURPOSE

Several reports suggest that cisplatin is associated with an increased risk of thromboembolism. However, because the excess risk of venous thromboembolic events (VTEs) with cisplatin-based chemotherapy has not been well described, we conducted a systemic review and meta-analysis of randomized controlled trials evaluating the incidence and risk of VTEs associated with cisplatin-based chemotherapy.

METHODS

PubMed was searched for articles published from January 1, 1990, to December 31, 2010. Eligible studies included prospective randomized phase II and III trials evaluating cisplatin-based versus non-cisplatin-based chemotherapy in patients with solid tumors. Data on all-grade VTEs were extracted. Study quality was calculated using Jadad scores. Incidence rates, relative risks (RRs), and 95% CIs were calculated using a random effects model.

RESULTS

A total of 8,216 patients with various advanced solid tumors from 38 randomized controlled trials were included. The incidence of VTEs was 1.92% (95% CI, 1.07 to 2.76) in patients treated with cisplatin-based chemotherapy and 0.79% (95% CI, 0.45 to 1.13) in patients treated with non-cisplatin-based regimens. Patients receiving cisplatin-based chemotherapy had a significantly increased risk of VTEs (RR, 1.67; 95% CI, 1.25 to 2.23; P = .01). Exploratory subgroup analysis revealed the highest RR of VTEs in patients receiving a weekly equivalent cisplatin dose > 30 mg/m(2) (2.71; 95% CI, 1.17 to 6.30; P = .02) and in trials reported during 2000 to 2010 (1.72; 95% CI, 1.27 to 2.34; P = .01).

CONCLUSION

Cisplatin is associated with a significant increase in the risk of VTEs in patients with advanced solid tumors when compared with non-cisplatin-based chemotherapy.

A phase I study of larotaxel (XRP9881) administered in combination with carboplatin in chemotherapy-naïve patients with stage IIIB or stage IV non-small cell lung cancer

PURPOSE

This primary objective of this phase I dose-escalation study was to define the maximum tolerated dose (MTD) and dose limiting toxicity (DLT) of larotaxel administered in combination with carboplatin in chemotherapy-naïve patients with advanced/metastatic non-small cell lung cancer (NSCLC).

METHODS

Eighteen patients with stage IIIB or IV NSCLC, in cohorts of three to six evaluable patients, were to receive every 3 weeks: larotaxel beginning at 45 mg/m(2) administered as a 1-h infusion, followed after 30 min by carboplatin (area under the concentration-time curve (AUC) = 6 mg/mL × min, later AUC = 5) as a 1-h infusion. Dose escalation of larotaxel up to 90 mg/m(2) was permitted according to DLT occurrence. Patients received ondansetron as prophylactic anti-emetic premedication.

RESULTS

In view of the toxicity encountered, the carboplatin dose was decreased for the later part of the study to AUC = 5 mg/mL × min. Eight of 18 treated patients experienced DLTs in the first cycle, including neutropenia and associated complications, diarrhea and fatigue. The MTD of the combination was defined as larotaxel 60 mg/m(2) with a carboplatin AUC of 6 mg/mL × min. Neutropenia, reported at grade 3/4 in 15/18 patients (83%), was the most common severe adverse event, reaching grade 4 in 14 patients (78%). Eleven patients (61%) experienced grade 3/4 non-hematological toxicity, predominantly dehydration, fatigue, infection, nausea and vomiting. One patient (6%) achieved a partial response and 11 (61%) had stable disease.

CONCLUSIONS

The combination of larotaxel and carboplatin is feasible and shows modest activity in chemotherapy-naïve patients with advanced/metastatic NSCLC. The principal toxicity was grade 3/4 neutropenia.

Microtubule-binding agents: a dynamic field of cancer therapeutics

Microtubules are dynamic filamentous cytoskeletal proteins composed of tubulin and are an important therapeutic target in tumour cells. Agents that bind to microtubules have been part of the pharmacopoeia of anticancer therapy for decades and until the advent of targeted therapy, microtubules were the only alternative to DNA as a therapeutic target in cancer. The screening of a range of botanical species and marine organisms has yielded promising new antitubulin agents with novel properties. In the current search for novel microtubule-binding agents, enhanced tumour specificity, reduced neurotoxicity and insensitivity to chemoresistance mechanisms are the three main objectives.

Larotaxel: broadening the road with new taxanes

Significant advances in cancer treatment have been achieved with novel targeted and state-of-the-art treatments. While the targeted treatments have received much attention in recent years, the more 'traditional' chemotherapeutic agents continue to play an important role in several malignancies. Former taxanes such as docetaxel and paclitaxel, with their broad anticancer activity, have contributed significantly to the improved treatment of a number of neoplastic diseases. Unfortunately, until now, the achievements obtained with these compounds have been mitigated by clinical limitations such as acquired or intrinsic resistance of tumors, poor CNS activity, allergic reactions and unfavorable toxicity profiles. Larotaxel (RPR 109881A) is a taxane analogue with a broad spectrum of activity and different toxicity profile and with the possible advantages of surpassing some mechanisms of resistance and penetrating into the CNS. The development path of this drug, its core clinical data and future treatment perspectives are discussed in this article.

Microtubule dynamics as a target in oncology

Drugs that affect microtubule dynamics, including the taxanes and vinca alkaloids, have been a mainstay in the treatment of leukemias and solid tumors for decades. New, more effective microtubule-targeting agents continue to enter into clinical trials and some, including the epothilone ixapebilone, have been approved for use. In contrast, several other drugs of this class with promising preclinical data were later shown to be ineffective or intolerable in animal models or clinical trials. In this review, we discuss the molecular mechanisms as well as preclinical and clinical results for a variety of microtubule-targeting agents in various stages of development. We also offer a frank discussion of which microtubule-targeting agents are amenable to further development based on their availability, efficacy and toxic profile.