Maximum Tolerated Dose and Pharmacokinetics of Paclitaxel Micellar in Patients with Recurrent Malignant Solid Tumours: A Dose-Escalation Study

A Library of Custom PEG-Lipids reveals a Double-PEG-Lipid with Drastically Enhanced Paclitaxel Solubility and Human Cancer Cell Cytotoxicity when used in Fluid Micellar Nanoparticles

Paclitaxel (PTX) is one of the most widely utilized chemotherapeutics globally. However, the extremely poor water solubility of paclitaxel necessitates a mechanism of delivery within blood. Fluid lipid PTX nanocarriers (lipids in the chain-melted state) show promise as PTX delivery vectors, but remain limited by their solubility of PTX within the membrane. To improve pharmacokinetics, membrane surfaces are typically coated with polyethylene glycol (PEG). Recent work has demonstrated the generation of a population of micelles within fluid lipid formulations containing a 2kDa PEG-lipid at a 10 mol% ratio. Driven by the positive curvature of the PEG-lipid (i.e. area of head group > area of tails), micelle-containing formulations were found to exhibit significantly higher uptake in cancer cells, cytotoxicity, and in vivo antitumor efficacy compared to formulations containing solely liposomes. Here, we describe the custom synthesis of a library of high-curvature micelle-inducing PEG-lipids and examine the effects of PEG chain length, chain branching (single- or double-PEG-lipid), and cationic charge on PTX solubility and cytotoxicity. We examined PEG-lipids at standard (10 mol%) and high (100-x mol%, where x=PTX mol%) formulation ratios. Remarkably, all formulations containing the synthesized high-curvature PEG-lipids had improved PTX solubility over unPEGylated formulations and commercially available DOPE-5k. The highest PTX solubility was found within the 100-xPTX mol% PEG-lipid micellar formulations, with particles made from 2k2 (two PEG2k chains) encapsulating 13 mol% PTX for up to 24 h. The pancreatic cancer cell line PC3 exhibited higher sensitivity to formulations containing PEG-lipid at 100-xPTX mol%, the most potent of which being formulations made from 2k2 (IC50 = 14 nM). The work presented here suggests formulations employing high-curvature PEG-lipids, particularly the double-PEG-lipid 2k2, hold great potential as next-generation PTX delivery systems owing to their high PTX solubility, enhanced cell cytotoxicity, and ability for precision targeting by affixation of ligands to the PEG molecules.

Paclitaxel Drug-Drug Interactions in the Military Health System

Background

Paclitaxel is an antineoplastic agent used to treat breast, lung, endometrial, cervical, pancreatic, sarcoma, and thymoma cancer. However, drugs that induce, inhibit, or are substrates of cytochrome P450 (CYP) isoenzymes 2C8 or 3A4 may alter the metabolism of paclitaxel, potentially impacting its effectiveness. The purposes of this study are to provide an overview of paclitaxel use, identify potential drugs that interact with paclitaxel, and describe their clinical manifestations.

Methods

A retrospective analysis was performed on patients receiving paclitaxel to evaluate types and stages of cancer, treatment regimens, and adverse events of paclitaxel alone or paclitaxel in combination with other antineoplastic drugs, using data retrieved in March 2022 from the US Department of Defense Cancer Registry. Additionally, the study compared the health issues and prescriptions of patients who completed treatment with those who discontinued treatment. It evaluated interactions of paclitaxel with noncancer drugs, particularly antidepressants metabolizing and inhibiting CYP3A4, using data from the Comprehensive Ambulatory/Professional Encounter Record and the Pharmacy Data Transaction Service database. Data were retrieved in October 2022.

Results

Of 702 patients prescribed paclitaxel, 338 completed treatment. Paclitaxel discontinuation alone vs concomitantly (P < .001) and 1 drug vs combination (P < .001) both were statistically significant. Patients who took paclitaxel concomitantly with a greater number of prescription drugs had a higher rate of treatment discontinuation than those who received fewer medications. Patients in the completed group received 9 to 56 prescription drugs, and those in the discontinued group were prescribed 6 to 70. Those who discontinued treatment had more diagnosed medical issues than those who completed treatment.

Conclusions

The study provides a comprehensive overview of paclitaxel usage from 1996 through 2022 and highlights potential drug interactions that may affect treatment outcomes. While the impact of prescription drugs on paclitaxel discontinuation is uncertain, paclitaxel and antidepressants do not have significant drug-drug interactions.

Polymeric Nanoparticles for Drug Delivery

The recent emergence of nanomedicine has revolutionized the therapeutic landscape and necessitated the creation of more sophisticated drug delivery systems. Polymeric nanoparticles sit at the forefront of numerous promising drug delivery designs, due to their unmatched control over physiochemical properties such as size, shape, architecture, charge, and surface functionality. Furthermore, polymeric nanoparticles have the ability to navigate various biological barriers to precisely target specific sites within the body, encapsulate a diverse range of therapeutic cargo and efficiently release this cargo in response to internal and external stimuli. However, despite these remarkable advantages, the presence of polymeric nanoparticles in wider clinical application is minimal. This review will provide a comprehensive understanding of polymeric nanoparticles as drug delivery vehicles. The biological barriers affecting drug delivery will be outlined first, followed by a comprehensive description of the various nanoparticle designs and preparation methods, beginning with the polymers on which they are based. The review will meticulously explore the current performance of polymeric nanoparticles against a myriad of diseases including cancer, viral and bacterial infections, before finally evaluating the advantages and crucial challenges that will determine their wider clinical potential in the decades to come.

Preclinical evaluation of singlet oxygen-cleavable prodrugs in combination with protoporphyrin IX-photodynamic therapy in an orthotopic rat model of non-muscle-invasive bladder cancer†

Photodynamic therapy (PDT) initially employed red light, which caused some patients to experience permanent bladder contractions. PDT using the FDA-approved drug hexaminolevulinate (HAL), which produces protoporphyrin IX (PpIX) in the tumor, showed some promise but has low efficacy in treating non-muscle-invasive bladder cancer (NMIBC). We developed singlet oxygen-activatable prodrugs of two anticancer drugs, paclitaxel and mitomycin C, to enhance the antitumor effect of PpIX-PDT without producing systemic side effects, by promoting only local release of the active chemotherapeutic agent. Orthotopic NMIBC model was used to compare the efficacy of prodrugs only, PpIX-PDT, and prodrugs + PpIX-PDT. 532 nm laser with a total power of 50 mW for 20 min (60 J, single treatment) was used with HAL and prodrugs. Histology and microscopic methods with image analysis were used to evaluate the tumor staging, antitumor efficacy, and local toxicity. Prodrug + PpIX-PDT produced superior antitumor efficacy than PpIX-PDT alone with statistical significance. Both PpIX-PDT alone and combination therapy resulted in mild damage to the bladder epithelium in the normal bladder area with no apparent damage to the muscle layer. Overall, SO-cleavable prodrugs improved the antitumor efficacy of PpIX-PDT without causing severe and permanent damage to the bladder muscle layer.

Nab-Paclitaxel in the Treatment of Gastrointestinal Cancers-Improvements in Clinical Efficacy and Safety

Taxanes (paclitaxel and docetaxel) are one of the most useful classes of anticancer drugs. Taxanes are highly hydrophobic; therefore, these drugs must be dissolved in organic solvents (polysorbate or Cremophor EL), which contribute to their toxicities. To reduce this toxicity and to enhance their efficacy, novel formulations have been developed. Nanoparticle albumin-bound paclitaxel (nab-paclitaxel) is an albumin-stabilized, Cremophor-free, and water-soluble nanoparticle formulation of paclitaxel. Nab-paclitaxel has better solubility and less infusion-associated toxicity compared to solvent-based paclitaxel. Additionally, nab-paclitaxel can be given at higher doses and concentrations compared with solvent-based paclitaxel. Based on its superior clinical efficacy and safety profile, nab-paclitaxel received FDA approval for metastatic breast cancer (2008) and NSCLC (2011). Among gastrointestinal cancers, it is now approved in the USA for treating patients with metastatic adenocarcinoma of the pancreas as first-line therapy in combination with gemcitabine. Furthermore, several clinical trials have suggested the potential efficacy of nab-paclitaxel as a single agent or in combination with other agents for the treatment of metastatic esophageal, gastric, bowel, and biliary tract cancers. Nab-paclitaxel has been demonstrated to have greater overall response rates (ORR) with enhanced progression-free survival (PFS), overall survival (OS) and a superior safety profile with fewer adverse effects in patients with gastrointestinal tract cancers. This review summarizes the advantages associated with nab-paclitaxel-based regimens in terms of improving clinical efficacy and the safety profile in upper gastrointestinal cancer.

Chronotherapy in dentistry: A scoping review

The circadian clock modulates almost all vital aspects of our physiology and metabolism, including processes relevant to dentistry, such as healing, inflammation and nociception. Chronotherapy is an emerging field aiming to improve therapeutic efficacy and decrease adverse effects on health outcomes. This scoping review aimed to systematically map the evidence underpinning chronotherapy in dentistry and to identify gaps in knowledge. We conducted a systematic scoping search using four databases (Medline, Scopus, CINAHL and Embase). We identified 3908 target articles screened by two blinded reviewers, and only original animal and human studies investigating the chronotherapeutic use of drugs or interventions in dentistry were included. Of the 24 studies included, 19 were human studies and five were animal studies. Chrono-radiotherapy and chrono-chemotherapy reduced treatment side effects and improved therapeutic response, leading to higher survival rates in cancer patients. Animal studies reported that tooth movement and periodontal tissue response to orthodontic forces follow a diurnal rhythm that might influence bone metabolism. Profound and prolonged local anesthesia could be achieved when injected in the evening. Although the overall quality of the included studies was low, chronotherapy applications in dentistry seem to have favourable outcomes, especially in head and neck cancer treatments.

Nanoparticle-mediated therapeutic management in cholangiocarcinoma drug targeting: Current progress and future prospects

Patients with cholangiocarcinoma (CCA) often have an unfavorable prognosis because of its insidious nature, low resectability rate, and poor response to anticancer drugs and radiotherapy, which makes early detection and treatment difficult. At present, CCA has a five-year overall survival rate (OS) of only 5%, despite advances in therapies. New an increasing number of evidence suggests that nanoplatforms may play a crucial role in enhancing the pharmacological effects and in reducing both short- and long-term side effects of cancer treatment. This document reviews the advantages and shortcomings of nanoparticles such as liposomes, polymeric nanoparticle，inorganic nanoparticle, nano-metals and nano-alloys, carbon dots, nano-micelles, dendrimer, nano-capsule, bio-Nanomaterials in the diagnosis and treatment of CCA and discuss the current challenges in of nanoplatforms for CCA.

Natural Taxanes: From Plant Composition to Human Pharmacology and Toxicity

Biologically active taxanes, present in small- to medium-sized evergreen conifers of various Taxus species, are widely used for their antioxidant, antimicrobial and anti-inflammatory effects, but mostly for their antitumour effects used in the treatment of solid tumours of the breast, ovary, lung, bladder, prostate, oesophagus and melanoma. More of the substances found in Taxus plant extracts have medical potential. Therefore, at the beginning of this review, we describe the methods of isolation, identification and determination of taxanes in different plant parts. One of the most important taxanes is paclitaxel, for which we summarize the pharmacokinetic parameters of its different formulations. We also describe toxicological risks during clinical therapy such as hypersensitivity, neurotoxicity, gastrointestinal, cardiovascular, haematological, skin and renal toxicity and toxicity to the respiratory system. Since the effect of the drug-form PTX is enhanced by various Taxus spp. extracts, we summarize published clinical intoxications and all fatal poisonings for the Taxus baccata plant. This showed that, despite their significant use in anticancer treatment, attention should also be focused on the risk of fatal intoxication due to ingestion of extracts from these plants, which are commonly found in our surroundings.

A tumor microenvironment-activated metal-organic framework-based nanoplatform for amplified oxidative stress-induced enhanced chemotherapy

Engineering a highly tumor microenvironment-responsive nanoplatform toward effective chemotherapy has always been a challenge in targeted cancer treatment. Metal-organic frameworks are a promising delivery system to reformulate previously approved drugs for enhanced chemotherapy, such as disulfiram (DSF). Herein, a tumor microenvironment-activated metal-organic framework-based nanoplatform DSF@MOF-199@FA has been fabricated to realize amplified oxidative stress-induced enhanced chemotherapy. Our results unveil that the copper ions and DSF released by DSF@MOF-199@FA in an acidic environment can be converted into toxic bis(N, N-diethyl dithiocarbamate) copper and then induce cell apoptosis. Simultaneously, we determined that the apoptosis outcome is further promoted by amplified oxidative stress through effective generation of reactive oxygen species and GSH elimination. In conclusion, this work provides a promising platform for effective anticancer treatment.

Anticancer Nanotherapeutics in Clinical Trials: The Work behind Clinical Translation of Nanomedicine

The ultimate goal of nanomedicine has always been the generation of translational technologies that can ameliorate current therapies. Cancer disease represented the primary target of nanotechnology applied to medicine, since its clinical management is characterized by very toxic therapeutics. In this effort, nanomedicine showed the potential to improve the targeting of different drugs by improving their pharmacokinetics properties and to provide the means to generate new concept of treatments based on physical treatments and biologics. In this review, we considered different platforms that reached the clinical trial investigation, providing an objective analysis about their physical and chemical properties and the working mechanism at the basis of their tumoritr opic properties. With this review, we aim to help other scientists in the field in conceiving their delivering platforms for clinical translation by providing solid examples of technologies that eventually were tested and sometimes approved for human therapy.

Current progress of nanomedicine for prostate cancer diagnosis and treatment

Prostate cancer (PCa) is the most common new cancer case and the second most fatal malignancy in men. Surgery, endocrine therapy, radiotherapy and chemotherapy are the main clinical treatment options for PCa. However, most prostate cancers can develop into castration-resistant prostate cancer (CRPC), and due to the invasiveness of prostate cancer cells, they become resistant to different treatments and activate tumor-promoting signaling pathways, thereby inducing chemoresistance, radioresistance, ADT resistance, and immune resistance. Nanotechnology, which can combine treatment with diagnostic imaging tools, is emerging as a promising treatment modality in prostate cancer therapy. Nanoparticles can not only promote their accumulation at the pathological site through passive targeting techniques for enhanced permeability and retention (EPR), but also provide additional advantages for active targeting using different ligands. This property results in a reduced drug dose to achieve the desired effect, a longer duration of action within the tumor and fewer side effects on healthy tissues. In addition, nanotechnology can create good synergy with radiotherapy, chemotherapy, thermotherapy, photodynamic therapy and gene therapy to enhance their therapeutic effects with greater scope, and reduce the resistance of prostate cancer. In this article, we intend to review and discuss the latest technologies regarding the use of nanomaterials as therapeutic and diagnostic tools for prostate cancer.

Beyond Formulation: Contributions of Nanotechnology for Translation of Anticancer Natural Products into New Drugs

Nature is the largest pharmacy in the world. Doxorubicin (DOX) and paclitaxel (PTX) are two examples of natural-product-derived drugs employed as first-line treatment of various cancer types due to their broad mechanisms of action. These drugs are marketed as conventional and nanotechnology-based formulations, which is quite curious since the research and development (R&D) course of nanoformulations are even more expensive and prone to failure than the conventional ones. Nonetheless, nanosystems are cost-effective and represent both novel and safer dosage forms with fewer side effects due to modification of pharmacokinetic properties and tissue targeting. In addition, nanotechnology-based drugs can contribute to dose modulation, reversion of multidrug resistance, and protection from degradation and early clearance; can influence the mechanism of action; and can enable drug administration by alternative routes and co-encapsulation of multiple active agents for combined chemotherapy. In this review, we discuss the contribution of nanotechnology as an enabling technology taking the clinical use of DOX and PTX as examples. We also present other nanoformulations approved for clinical practice containing different anticancer natural-product-derived drugs.

Novel Self-Assembled Micelles With Increased Tumor Penetration and Anti-Tumor Efficiency Against Breast Cancer

PURPOSE

Recently, docetaxel (DTX) micelles based on retinoic acid derivative surfactants showed lower systemic toxicity and bioequivalence to polysorbate-solubilized docetaxel (Taxotere®) in a phase II clinical study. However, the poor stability of these surfactants in vitro and in vivo led to extremely harsh storage conditions with methanol, and the formed micelles were quickly disintegrated with rapid drug burst release in vivo. To further enhance the stability and accumulation in tumors of DTX micelles, a novel surfactant based on acitretin (ACMeNa) was synthesized and used to prepare DTX micelles to improve anti-tumor efficiency.

METHODS

Novel micelle-forming excipients were synthesized, and the micelles were prepared using the thin film hydration technique. The targeting effect in vitro, distribution in the tumor, and its mechanism were observed. Pharmacokinetics and anti-tumor effect were further investigated in rats and tumor-bearing female mice, respectively.

RESULTS

The DTX-micelles prepared with ACMeNa (ACM-DTX) exhibited a small size (21.9 ± 0.3 nm), 39% load efficiency, and excellent stability in vitro and in vivo. Long circulation time, sustained and steady accumulation, and strong penetration in the tumor were observed in vivo, contributing to a better anti-tumor effect and lower adverse effects.

CONCLUSIONS

The micelles formed by ACMeNa showed a better balance between anti-tumor and adverse effects. It is a promising system for delivering hydrophobic molecules for cancer therapy.

Nanodiscs: a versatile nanocarrier platform for cancer diagnosis and treatment

Cancer therapy is a significant challenge due to insufficient drug delivery to the cancer cells and non-selective killing of healthy cells by most chemotherapy agents. Nano-formulations have shown great promise for targeted drug delivery with improved efficiency. The shape and size of nanocarriers significantly affect their transport inside the body and internalization into the cancer cells. Non-spherical nanoparticles have shown prolonged blood circulation half-lives and higher cellular internalization frequency than spherical ones. Nanodiscs are desirable nano-formulations that demonstrate enhanced anisotropic character and versatile functionalization potential. Here, we review the recent development of theranostic nanodiscs for cancer mitigation ranging from traditional lipid nanodiscs encased by membrane scaffold proteins to newer nanodiscs where either the membrane scaffold proteins or the lipid bilayers themselves are replaced with their synthetic analogues. We first discuss early cancer detection enabled by nanodiscs. We then explain different strategies that have been explored to carry a wide range of payloads for chemotherapy, cancer gene therapy, and cancer vaccines. Finally, we discuss recent progress on organic-inorganic hybrid nanodiscs and polymer nanodiscs that have the potential to overcome the inherent instability problem of lipid nanodiscs.

Enhanced Anti-Tumor Effect of Folate-Targeted FA-AMA-hyd-DOX Conjugate in a Xenograft Model of Human Breast Cancer

Folate-aminocaproic acid-doxorubicin (FA-AMA-hyd-DOX) was firstly synthesized by our group. It was indicated that FA-AMA-hyd-DOX was pH-responsive, and had strong cytotoxicity on a folate receptor overexpressing cell line (KB cells) in vitro. The aim of our study was to further explore the potential use of FA-AMA-hyd-DOX as a new therapeutic drug for breast cancer. The cellular uptake and the antiproliferative activity of the FA-AMA-hyd-DOX in MDA-MB-231 cells were measured. Compared with DOX, FA-AMA-hyd-DOX exhibited higher targeting ability and cytotoxicity to FR-positive tumor cells. Subsequently, the tissue distribution of FA-AMA-hyd-DOX was studied, and the result confirmed that DOX modified by FA can effectively increase the selectivity of drugs in vivo. After determining the maximum tolerated dose (MTD) of FA-AMA-hyd-DOX in MDA-MB-231 tumor-bearing nude mice, the antitumor effects and the in vivo safety of FA-AMA-hyd-DOX were systematically evaluated. The data showed that FA-AMA-hyd-DOX could effectively increase the dose of DOX tolerated by tumor-bearing nude mice and significantly inhibit MDA-MB-231 tumor growth in vivo. Furthermore, FA-AMA-hyd-DOX treatment resulted in almost no obvious damage to the mice. All the positive data suggest that FA-targeted FA-AMA-hyd-DOX is a promising tumor-targeted compound for breast cancer therapy.

All-trans retinoic acid in anticancer therapy: how nanotechnology can enhance its efficacy and resolve its drawbacks

Introduction: All-trans retinoic acid (ATRA, tretinoin) is the main drug used in the treatment of acute promyelocytic leukemia (APL). Despite its impressive activity against APL, the same could not be clinically observed in other types of cancer. Nanotechnology can be a tool to enhance ATRA anticancer efficacy and resolve its drawbacks in APL as well as in other malignancies.Areas covered: This review covers ATRA use in APL and non-APL cancers, the problems that were found in ATRA therapy and how nanoencapsulation can aid to circumvent them. Pre-clinical results obtained with nanoencapsulated ATRA are shown as well as the two ATRA products based on nanotechnology that were clinically tested: ATRA-IV® and Apealea®.Expert opinion: ATRA presents interesting properties to be used in anticancer therapy with a notorious differentiation and antimetastatic activity. Bioavailability and resistance limitations impair the use of ATRA in non-APL cancers. Nanotechnology can circumvent these issues and provide tools to enhance its anticancer activities, such as co-loading of multiple drug and active targeting to tumor site.

Recent progress in nanomedicine for enhanced cancer chemotherapy

As one of the most important cancer treatment strategies, conventional chemotherapy has substantial side effects and leads easily to cancer treatment failure. Therefore, exploring and developing more efficient methods to enhance cancer chemotherapy is an urgently important problem that must be solved. With the development of nanotechnology, nanomedicine has showed a good application prospect in improving cancer chemotherapy. In this review, we aim to present a discussion on the significant research progress in nanomedicine for enhanced cancer chemotherapy. First, increased enrichment of drugs in tumor tissues relying on different targeting ligands and promoting tissue penetration are summarized. Second, specific subcellular organelle-targeted chemotherapy is discussed. Next, different combinational strategies to reverse multidrug resistance (MDR) and improve the effective intracellular concentration of therapeutics are discussed. Furthermore, the advantages of combination therapy for cancer treatment are emphasized. Finally, we discuss the major problems facing therapeutic nanomedicine for cancer chemotherapy, and propose possible future directions in this field.

Emerging nanotaxanes for cancer therapy

The clinical application of taxane (including paclitaxel, docetaxel, and cabazitaxel)-based formulations is significantly impeded by their off-target distribution, unsatisfactory release, and acquired resistance/metastasis. Recent decades have witnessed a dramatic progress in the development of high-efficiency, low-toxicity nanotaxanes via the use of novel biomaterials and nanoparticulate drug delivery systems (nano-DDSs). Thus, in this review, the achievements of nanotaxanes-targeted delivery and stimuli-responsive nano-DDSs-in preclinical or clinical trials have been outlined. Then, emerging nanotherapeutics against tumor resistance and metastasis have been overviewed, with a particular emphasis on synergistic therapy strategies (e.g., combination with surgery, chemotherapy, radiotherapy, biotherapy, immunotherapy, gas therapy, phototherapy, and multitherapy). Finally, the latest oral nanotaxanes have been briefly discussed.

A Compressive Review about Taxol®: History and Future Challenges

Taxol^®, which is also known as paclitaxel, is a chemotherapeutic agent widely used to treat different cancers. Since the discovery of its antitumoral activity, Taxol^® has been used to treat over one million patients, making it one of the most widely employed antitumoral drugs. Taxol^® was the first microtubule targeting agent described in the literature, with its main mechanism of action consisting of the disruption of microtubule dynamics, thus inducing mitotic arrest and cell death. However, secondary mechanisms for achieving apoptosis have also been demonstrated. Despite its wide use, Taxol^® has certain disadvantages. The main challenges facing Taxol^® are the need to find an environmentally sustainable production method based on the use of microorganisms, increase its bioavailability without exerting adverse effects on the health of patients and minimize the resistance presented by a high percentage of cells treated with paclitaxel. This review details, in a succinct manner, the main aspects of this important drug, from its discovery to the present day. We highlight the main challenges that must be faced in the coming years, in order to increase the effectiveness of Taxol^® as an anticancer agent.

A randomized phase III trial in patients with recurrent platinum sensitive ovarian cancer comparing efficacy and safety of paclitaxel micellar and Cremophor EL-paclitaxel

OBJECTIVE

Paclitaxel micellar was developed to avoid Cremophor-EL (Cr-EL) associated dose limiting toxicity and to allow a shorter infusion time. The efficacy and safety of paclitaxel micellar (+carboplatin) was compared to Cr-EL paclitaxel (+carboplatin) in recurrent platinum-sensitive ovarian, fallopian tube or peritoneal carcinoma.

METHODS

This was a multicentre, open-label, randomized phase III trial. Adult patients with recurrent disease was assigned to six 3-week cycles of paclitaxel micellar (250 mg/m²) administered as 1-h infusion or Cr-EL paclitaxel (175 mg/m²) as 3-h infusion. Both arms received carboplatin (AUC 5-6). Primary objective was non-inferiority for progression free survival (PFS) using computed tomography scans. Overall survival (OS) was included as secondary endpoint.

RESULTS

Between 2009 and 2013, 789 patients were randomized to receive experimental (N = 397) or control (N = 392) treatment. PFS for paclitaxel micellar was non-inferior to Cr-EL paclitaxel with a hazard ratio of 0.86 (95% CI: 0.72;1.03) in the per protocol population (PP), favouring paclitaxel micellar (non-inferiority margin was 1.2). Non-inferiority of OS was shown in the PP population with a hazard ratio of 0.95 (95% CI: 0.78; 1.16), favouring paclitaxel micellar (non-inferiority margin was 1.185). The most common adverse event was neutropenia (grade ≥ 3); 245 patients (79%) for paclitaxel micellar vs 213 patients (66%) for Cr-EL paclitaxel. The frequency of peripheral sensory neuropathy (any grade) was similar between the arms; 16% for paclitaxel micellar and 20% for Cr-EL paclitaxel.

CONCLUSION

Paclitaxel micellar (+ carboplatin) is non-inferior to Cr-EL paclitaxel (+ carboplatin) in terms of PFS and OS in the studied population. It provides a treatment option of a higher paclitaxel dose with a shorter infusion time without mandatory premedication.

TRIAL REGISTRATION NUMBER

2008-002668-32 (EudraCT), NCT00989131 (ClinicalTrials.gov).

Pharmacokinetics of Total and Unbound Paclitaxel After Administration of Paclitaxel Micellar or Nab-Paclitaxel: An Open, Randomized, Cross-Over, Explorative Study in Breast Cancer Patients

INTRODUCTION

Paclitaxel micellar is a novel formulation of paclitaxel in which retinoic acid derivates solubilize paclitaxel. The aim of the present study was to compare the unbound and total plasma pharmacokinetics of the new formulation with those of nanoparticle albumin-bound (nab)-paclitaxel and to further assess its safety.

METHODS

In this open, randomized, cross-over study, 28 female patients with breast cancer were given paclitaxel micellar and nab-paclitaxel as a 1-h intravenous infusion at a dose of 260 mg/m2. Plasma samples were collected during 10 h, which were projected to cover at least 80% of the area to infinite time, AUCinf. Unbound paclitaxel was measured in ultrafiltrate of plasma. Total paclitaxel in plasma was measured after protein precipitation with acetonitrile. Both assays used ultra-performance liquid chromatography (UPLC) followed by MS/MS for drug quantification. The unbound fraction, fu, was calculated as the ratio between the unbound and the total concentration.

RESULTS

No difference in fu of paclitaxel between the two formulations was observed. Statistical comparison of AUC0-10h and Cmax of unbound paclitaxel demonstrated that the two formulations met the criteria for bioequivalence. Regarding total paclitaxel levels, Cmax but not AUC0-10h met the criteria. This study supports a safe administration of paclitaxel micellar.

CONCLUSION

The two formulations, paclitaxel micellar and nab-paclitaxel, behaved similarly following infusion. Probably, both formulations dissociate immediately in the blood, whereupon released paclitaxel rapidly distributes into tissue. Judged from the bioequivalence demonstrated for unbound paclitaxel, the two formulations are considered clinically equivalent.

TRIAL REGISTRATION

EudraCT no.: 2010-019838-27.

FUNDING

Oasmia Pharmaceutical AB.