Comparative study of the antitumor activity of Nab-paclitaxel and intraperitoneal solvent-based paclitaxel regarding peritoneal metastasis in gastric cancer

Innovative strategies for effective paclitaxel delivery: Recent developments and prospects

PURPOSE

Paclitaxel is an effective chemotherapeutic agent against a variety of cancer types. However, the clinical utility of paclitaxel is restricted by its poor solubility in water and high toxicity, resulting in low drug tolerance. These difficulties could be resolved by using suitable pharmacological carriers. Hence, it is essential to determine innovative methods of administering this effective medication to overcome paclitaxel's inherent limitations.

METHODS

An extensive literature search was conducted using multiple electronic databases to identify relevant studies published.

RESULTS

In this comprehensive analysis, many different paclitaxel delivery systems are covered and discussed, such as albumin-bound paclitaxel, polymeric micelles, paclitaxel-loaded liposomes, prodrugs, cyclodextrins, and peptide-taxane conjugates. Moreover, the review also covers various delivery routes of conventional paclitaxel or novel paclitaxel formulations, such as oral administration, local applications, and intraperitoneal delivery.

CONCLUSION

In addition to albumin-bound paclitaxel, polymeric micelles appear to be the most promising formulations for innovative drug delivery systems at present. A variety of variants of polymeric micelles are currently undergoing advanced phases of clinical trials.

Preclinical Activity of Two Paclitaxel Nanoparticle Formulations After Intraperitoneal Administration in Ovarian Cancer Murine Xenografts

Background

Epithelial ovarian cancer is associated with high mortality due to diagnosis at later stages associated with peritoneal involvement. Several trials have evaluated the effect of intraperitoneal treatment. In this preclinical study, we report the efficacy, pharmacokinetics and pharmacodynamics of intraperitoneal treatment with two approved nanomolecular formulations of paclitaxel (nab-PTX and mic-PTX) in a murine ovarian cancer xenograft model.

Methods

IC50 was determined in vitro on three ovarian cancer cell lines (OVCAR-3, SK-OV-3 and SK-OV-3-Luc IP1). EOC xenografts were achieved using a modified subperitoneal implantation technique. Drug treatment was initiated 2 weeks after engraftment, and tumor volume and survival were assessed. Pharmacokinetics and drug distribution effects were assessed using UHPLC-MS/MS and MALDI imaging mass spectrometry, respectively. Pharmacodynamic effects were analyzed using immunohistochemistry and transmission electron microscopy using standard protocols.

Results

We demonstrated sub-micromolar IC50 concentrations for both formulations on three EOC cancer cell lines in vitro. Furthermore, IP administration of nab-PTX or mic-PTX lead to more than 2-fold longer survival compared to a control treatment of IP saline administration (30 days in controls, 66 days in nab-PTX treated animals, and 76 days in mic-PTX animals, respectively). We observed higher tissue uptake of drug following nab-PTX administration when compared to mic-PTX, with highest uptake after 4 hours post-treatment, and confirmed this lower uptake of mic-PTX using HPLC on digested tumor samples. Furthermore, apoptosis was not increased in tumor implants up to 24h post-treatment.

Conclusion

Intraperitoneal administration of both nab-PTX and mic-PTX results in a significant anticancer efficacy and survival benefit in a mouse OC xenograft model.

Advances in the management of peritoneal malignancies

Peritoneal surface malignancies (PSMs) are usually associated with a poor prognosis. Nonetheless, in line with advances in the management of most abdominopelvic metastatic diseases, considerable progress has been made over the past decade. An improved understanding of disease biology has led to the more accurate prediction of neoplasia aggressiveness and the treatment response and has been reflected in the proposal of new classification systems. Achieving complete cytoreductive surgery remains the cornerstone of curative-intent treatment of PSMs. Alongside centralization in expert centres, enabling the delivery of multimodal and multidisciplinary strategies, preoperative management is a crucial step in order to select patients who are most likely to benefit from surgery. Depending on the specific PSM, the role of intraperitoneal chemotherapy and of perioperative systemic chemotherapy, in particular, in the neoadjuvant setting, is established in certain scenarios but questioned in several others, although more prospective data are required. In this Review, we describe advances in all aspects of the management of PSMs including disease biology, assessment and improvement of disease resectability, perioperative management, systemic therapy and pre-emptive management, and we speculate on future research directions.

Intraperitoneal drug delivery systems releasing cytostatic agents to target gastro-intestinal peritoneal metastases in laboratory animals: a systematic review

For peritoneal metastases (PM), there are few curative treatment options, and they are only available for a select patient group. Recently, new therapies have been developed to deliver intraperitoneal chemotherapy for a prolonged period, suitable for a larger patient group. These drug delivery systems (DDSs) seem promising in the experimental setting. Many types of DDSs have been explored in a variety of animal models, using different cytostatics. This review aimed to provide an overview of animal studies using DDSs containing cytostatics for the treatment of gastro-intestinal PM and identify the most promising therapeutic combinations. The review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and Systematic Review Center for Laboratory Animal Experimentation (SYRCLE) guidelines. The 35 studies included revealed similar results: using a cytostatic-loaded DDS to treat PM resulted in a higher median survival time (MST) and a lower intraperitoneal tumor load compared to no treatment or treatment with a ‘free’ cytostatic or an unloaded DDS. In 65% of the studies, the MST was significantly longer and in 24% the tumor load was significantly lower in the animals treated with cytostatic-loaded DDS. The large variety of experimental setups made it impossible to identify the most promising DDS-cytostatic combination. In most studies, the risk of bias was unclear due to poor reporting. Future studies should focus more on improving the clinical relevance of the experiments, standardizing the experimental study setup, and improving their methodological quality and reporting.

Efficacy of AS versus SOX regimen as first-line chemotherapy for gastric cancer patients with peritoneal metastasis: a real-world study

Background

To compare the prognosis of first-line systemic chemotherapy of AS (Albumin-bound paclitaxel and S-1) versus SOX (S-1 and oxaliplatin) regimen in Chinese gastric cancer patients with peritoneal metastasis.

Methods

This was a real-world study of gastric cancer patients with peritoneal metastasis who have been treated with AS or SOX regimen as first-line chemotherapy. Patients were matched by the method of propensity score matching (PSM). The primary and secondary endpoints were overall survival (OS) and progress-free survival (PFS).

Results

A total of 108 gastric cancer patients with peritoneal metastasis were enrolled after PSM analysis. There was no significant difference between AS and SOX regimen based on gender, age, ascites, treatment cycles, gastric cancer resection, received checkpoint inhibitors, and HER-2 expression after PSM analysis. The median OS (14.13 vs. 11.17 months, p = 0.0356) and median PFS (10.30 vs. 6.70 months, p = 0.0003) of patients who received AS regimen were longer than those treated by SOX regimen as first-line systemic chemotherapy. In sub-group analysis, the median OS and median PFS were longer for patients in AS regimen than SOX regimen in Lauren diffuse type. The occurrence of toxicity between the two groups was shown no significant difference.

Conclusions

The results verified that AS regimen was more effective than SOX chemotherapy in gastric cancer patients with peritoneal metastasis, especially in Lauren diffuse type.

Addition of sintilimab to nanoparticle albumin-bound paclitaxel and S-1 as adjuvant therapy in stage IIIC gastric cancer

The prognosis of stage III gastric cancer (GC) is not satisfying and the specific chemotherapy regimens for GC of stage IIIC based on the 8th edition of the UICC/AJCC TNM staging system are still inconclusive. Peritoneal recurrence is the common and severe relapse pattern. Nanoparticle albumin-bound paclitaxel (Nab-PTX) is safer and more effective than PTX in the peritoneal metastasis. Clinical trial has demonstrated the safety and efficacy of sintilimab in GC. A combination of Nab-PTX, S-1 and sintilimab could be a promising triplet regimen as adjuvant therapy for GC. The aim of this article is to describe the design of this prospective Dragon-VII trial, conducted to evaluate the safety and efficacy of the combination of Nab-PTX, S-1 and sintilimab. Clinical trial registration: NCT04781413.

Clinical outcome of patients with inoperable pancreatic cancer treated with FOLFIRINOX or gemcitabine plus Nab‑paclitaxel as a first‑line therapy: A retrospective analysis

The present study aimed to evaluate the clinical benefits of leucovorin, 5-fluorouracil, irinotecan and oxaliplatin (FOLFIRINOX) vs. gemcitabine plus Nab-paclitaxel (GnP) as a first-line therapy for patients with inoperable pancreatic cancer. For this purpose, in-house data available for 45 patients who received FOLFIRINOX or GnP as first-line treatment between 2014 and 2019 were retrospectively analyzed. In total, 21 and 24 patients received FOLFIRINOX and GnP, respectively. Although there were no significant differences in the median progression-free survival, the median overall survival was longer in the FOLFIRINOX group than in the GnP group (16.7 vs. 7.2 months). A total of 14 patients received FOLFIRINOX followed by GnP, whereas 3 patients received GnP followed by FOLFIRINOX. All patients who did not switch to second-line therapy owing to poor feasibility were included in the GnP group. The data indicated that patients receiving GnP as first-line therapy were less likely to switch to FOLFIRINOX and, consequently, had a worse prognosis.

Targeting Strategies for Enhancing Paclitaxel Specificity in Chemotherapy

Paclitaxel (PTX) has been used for cancer treatment for decades and has become one of the most successful chemotherapeutics in the clinic and financially. However, serious problems with its use still exist, owing to its poor solubility and non-selective toxicity. With respect to these issues, recent advances have addressed the water solubility and tumor specificity related to PTX application. Many measures have been proposed to remedy these limitations by enhancing tumor recognition via ligand-receptor-mediated targeting as well as other associated strategies. In this review, we investigated various kinds of ligands that have emerged as PTX tumor-targeting tools. In particular, this article highlights small molecule-, protein-, and aptamer-functionalized conjugates and nanoparticles (NPs), providing a promising approach for PTX-based individualized treatment prospects.

Phase 2 study of bevacizumab plus carboplatin/nab-paclitaxel followed by bevacizumab plus nab-paclitaxel for non-squamous non-small cell lung cancer with malignant pleural effusion

Objectives Vascular endothelial growth factor plays an important role in the pathogenesis of malignant pleural effusion (MPE). We previously showed the efficacy of bevacizumab (Bev) plus carboplatin (CBDCA)/paclitaxel (PTX) in the treatment of non-small lung cell cancer (NSCLC) with MPE. However, the toxicities were a little severe, and the efficacy was not satisfied sufficiently. Therefore, we conducted a phase II study for NSCLC with MPE to evaluate the efficacy and safety of Bev plus CBDCA/nab-PTX, which is a new combination therapy. Methods Chemotherapy-naive non-squamous (SQ) NSCLC patients with MPE participated in the study. A single aspiration (not allowing chest tube drainage) was allowed before chemotherapy. Patients received a maximum of six cycles of Bev (15 mg/kg, day1) plus CBDCA (AUC 6, day1)/nab-PTX (100 mg/m², day1, 8) every 3 weeks followed by Bev (15 mg/kg, day1) plus nab-PTX (100 mg/m², day1, 8) every 3 weeks without disease progression or unacceptable severe toxicities. The primary endpoint was objective response rate (ORR). Results The study enrollment was ceased because of suspension of the registration period (as scheduled) after 12 of 20 planned patients were treated successfully between March 2014 and February 2018. The ORR was 58.3 % (95 % CI, 27.7-84.8 %), and the disease control rate was 100 % (95 % CI, 73.5-100 %). Eight patients received maintenance therapy. Median progression-free and overall survival times were 14.4 and 26.9 months, respectively. Most patients experienced hematological toxicities, including ≥ grade 3 neutropenia and anemia; none experienced severe bleeding events and grade 5 toxicities. Conclusion The combination of Bev plus CBDCA/nab-PTX, a novel combination, might have efficacy with acceptable toxicities in chemotherapy-naïve non-SQ NSCLC patients with MPE.Trial Registration University Hospital Medical Information Network in Japan (UMIN) Clinical Trials Registry (No. UMIN000013329) registered on 4th March 2014.

Therapeutic efficacy of a paclitaxel-loaded nanofibrillated bacterial cellulose (PTX/NFBC) formulation in a peritoneally disseminated gastric cancer xenograft model

Nano-fibrillated bacterial cellulose (NFBC) is a safe, biocompatible material that can be prepared by culturing a cellulose-producing bacterium in a culture supplemented with carboxymethylcellulose (CMC) or hydroxypropylcellulose (HPC). CM-NFBC and HP-NFBC, prepared using CMC or HPC, show hydrophilicity and amphiphilicity, respectively, and thus they could be useful carriers for hydrophobic anticancer agents such as paclitaxel (PTX). In the present study, we prepared novel PTX formulations for intraperitoneal administration by associating PTX with either CM-NFBC or HP-NFBC and studied their therapeutic efficacy on peritoneally disseminated gastric cancer in a xenograft nude mouse model. Freeze-dried PTX formulations (PTX/CM-NFBC and PTX/HP-NFBC) were quickly reconstituted with saline without any foaming, compared to nanoparticle albumin-bound PTX (nab-PTX, Abraxane®). Both PTX/NFBC formulations extended the mean survival times in our xenograft murine models compared with either free PTX or nab-PTX. The PTX/NFBC formulations reduced systemic side effects of free PTX relating to weight loss. In our disseminated gastric peritoneal cancer model, the PTX/NFBC formulation increased the therapeutic index for PTX by increasing the therapeutic efficacy and decreasing toxicity. NFBCs should receive consideration as improved carriers for the clinical delivery of hydrophobic anticancer drugs such as PTX in malignancies in the abdominal cavity with peritoneal metastasis and dissemination.

Current status of conversion surgery for stage IV gastric cancer

Palliative chemotherapy with best supportive care is a mainstay for patients with gastric cancer (GC) and distant metastasis. However, with advances in GC chemotherapy, multimodal treatment, including perioperative chemotherapy plus conversion surgery, has attracted attention as a new strategy to improve the outcome of patients with stage IV disease. Conversion surgery is defined as surgical treatment aimed at R0 resection after a good response to induction chemotherapy for tumors originally considered unresectable or marginally resectable for technical and/or oncological reasons. Various biological characteristics differ, depending on each metastatic condition in stage IV GC. The main metastatic pathways of GC can be divided into three categories: lymphatic, hematogenous, and peritoneal. In each category, considerable historical data on conversion surgery have demonstrated the benefits of individualized approaches. However, owing to the diversity of these conditions, a common definition, including the choice of induction chemotherapy, optimal timing of resection, and eligibility for conversion surgery, has not been established among surgical oncologists. Thus, we explore the current and future treatment options by reviewing the literature on this controversial topic comprehensively.

Targeting Strategies for Enhancing Paclitaxel Specificity in Chemotherapy

Paclitaxel (PTX) has been used for cancer treatment for decades and has become one of the most successful chemotherapeutics in the clinic and financially. However, serious problems with its use still exist, owing to its poor solubility and non-selective toxicity. With respect to these issues, recent advances have addressed the water solubility and tumor specificity related to PTX application. Many measures have been proposed to remedy these limitations by enhancing tumor recognition via ligand-receptor-mediated targeting as well as other associated strategies. In this review, we investigated various kinds of ligands that have emerged as PTX tumor-targeting tools. In particular, this article highlights small molecule-, protein-, and aptamer-functionalized conjugates and nanoparticles (NPs), providing a promising approach for PTX-based individualized treatment prospects.

Retrospective cohort study of nanoparticle albumin-bound paclitaxel plus ramucirumab versus paclitaxel plus ramucirumab as second-line treatment in patients with advanced gastric cancer

BACKGROUND

Nanoparticle albumin-bound paclitaxel (nab-PTX) has shown non-inferiority to paclitaxel (PTX) as second-line therapy for advanced gastric cancer (AGC) with fewer infusion-related reactions. The efficacy and safety of nab-PTX plus ramucirumab (RAM) was reported in a phase II trial; however, there is no randomized trial comparing this regimen with PTX plus RAM in patients with AGC. This retrospective study aimed to investigate the efficacy and safety of nab-PTX plus RAM versus PTX plus RAM in patients with AGC.

METHODS

This study included patients with AGC who received nab-PTX plus RAM from September 2017 to January 2019 or PTX plus RAM from June 2015 to August 2017 as second-line chemotherapy in our hospital.

RESULTS

A total of 113 and 138 patients who received nab-PTX plus RAM and PTX plus RAM, respectively, were analyzed. Median progression-free survival (PFS) was 3.9 months (95% confidence interval [CI]: 3.4-4.3) in the nab-PTX plus RAM group and 3.9 months (95% CI: 3.1-4.7) in the PTX plus RAM group (hazard ratio [HR]: 1.08; 95% CI: 0.83-1.40; P = 0.573). Median overall survival (OS) was 10.9 months (95% CI: 9.3-12.7) in the nab-PTX plus RAM group and 10.3 months (95% CI: 8.5-12.0) in the PTX plus RAM group (hazard ratio: 0.82; 95% CI: 0.61-1.10; P = 0.188). In patients with moderate/massive ascites, favorable outcomes for progression-free survival were observed in the nab-PTX plus RAM group compared with the PTX plus RAM group. Although anemia and fatigue (any grade) were more frequent in the nab-PTX plus RAM group, discontinuation of study treatment was not increased in the nab-PTX plus RAM group. There was no occurrence of hypersensitivity reaction in the nab-PTX plus RAM group, while two patients (1.4%) experienced grade 3 hypersensitivity reactions in the PTX plus RAM group.

CONCLUSIONS

The combination of nab-PTX plus RAM showed a similar efficacy and safety profile to PTX plus RAM as second-line treatment for patients with AGC.

EBV-miR-BART12 accelerates migration and invasion in EBV-associated cancer cells by targeting tubulin polymerization-promoting protein 1

Epstein-Barr virus (EBV) infection leads to cancers with an epithelial origin, such as nasopharyngeal cancer and gastric cancer, as well as multiple blood cell-based malignant tumors, such as lymphoma. Interestingly, EBV is also the first virus found to carry genes encoding miRNAs. EBV encodes 25 types of pre-miRNAs which are finally processed into 44 mature miRNAs. Most EBV-encoded miRNAs were found to be involved in the occurrence and development of EBV-related tumors. However, the function of EBV-miR-BART12 remains unclear. The findings of the current study revealed that EBV-miR-BART12 binds to the 3'UTR region of Tubulin Polymerization-Promoting Protein 1 (TPPP1) mRNA and downregulates TPPP1, thereby promoting the invasion and migration of EBV-related cancers, such as nasopharyngeal cancer and gastric cancer. The mechanism underlying this process was found to be the inhibition of TPPP1 by EBV-miRNA-BART12, which, in turn, inhibits the acetylation of α-tubulin, and promotes the dynamic assembly of microtubules, remodels the cytoskeleton, and enhances the acetylation of β-catenin. β-catenin activates epithelial to mesenchymal transition (EMT). These two processes synergistically promote the invasion and metastasis of tumor cells. To the best of our knowledge, this is the first study to reveal the role of EBV-miRNA-BART12 in the development of EBV-related tumors as well as the mechanism underlying this process, and suggests potential targets and strategies for the treatment of EBV-related tumors.

Phase 1 Study of Combined Chemotherapy of Nab-Paclitaxel, S-1, and Oxaliplatin for Gastric Cancer with Peritoneal Metastasis (NSOX Study)

OBJECTIVES

A regimen of S-1 combined with oxaliplatin (SOX) has been widely used as the first-line regimen for advanced gastric cancer. To further improve the antitumor efficacy for gastric cancer patients with peritoneal metastasis, we added nab-paclitaxel to the established SOX regimen (NSOX). Nab-paclitaxel (nanoparticle albumin-bound paclitaxel) has effective transferability to tumor tissues and strong antitumor effects for peritoneal metastasis. We performed a phase 1 study of this regimen to determine the maximum tolerated dose (MTD) and the recommended dose (RD) in patients with gastric cancer with peritoneal metastasis.

METHODS

The NSOX regimen involved 21-day cycles with escalated doses of nab-paclitaxel (50 [level 1] to 80 [level 4] mg/m2 on days 1 and 8) and fixed doses of oxaliplatin (100 mg/m2 on day 1) and S-1 (80 mg/m2/day for 2 weeks).

RESULTS

Six patients with gastric cancer with peritoneal metastasis were enrolled. The MTD was determined to be dose level 2, as 2 of 3 patients experienced dose-limiting toxicities (DLTs), grade 4 non-hematological toxicities. One patient experienced acute myocardial infarction, and the other patient developed jejunal perforation. There were no treatment-related deaths. No patients experienced DLTs, so the RD was determined to be dose level 1.

CONCLUSIONS

The NSOX regimen was shown to be a tolerable regimen and may be a promising triplet therapy for patients with gastric cancer with peritoneal metastasis.

Weekly paclitaxel plus ramucirumab versus weekly nab-paclitaxel plus ramucirumab for unresectable advanced or recurrent gastric cancer with peritoneal dissemination refractory to first-line therapy-the P-SELECT trial (WJOG10617G)-a randomised phase II trial by the West Japan Oncology Group

BACKGROUND

Ramucirumab (RAM) with weekly paclitaxel (wPTX) is a standard second-line therapy for advanced or recurrent gastric cancer. Nanoparticle albumin-bound paclitaxel (nab-PTX), an albumin-bound form of PTX, was developed to improve the therapeutic index of taxane treatment. However, the ABSOLUTE trial showed the non-inferiority of weekly nab-PTX (w-nab-PTX) to wPTX with respect to overall survival (OS) as second-line therapy for advanced or recurrent gastric cancer, and subgroup analysis of patients with peritoneal dissemination showed favourable OS and progression-free survival (PFS) in the w-nab-PTX arm compared to those in the wPTX arm. This study evaluated whether w-nab-PTX plus RAM is more effective than wPTX plus RAM for patients with peritoneal dissemination.

METHODS

The P-SELECT trial (WJOG10617G) is a prospective, open-label, multicentre, randomised phase II study evaluating wPTX plus RAM (arm A) versus w-nab-PTX plus RAM (arm B). Key eligibility criteria include the following: 1) histologically proven adenocarcinoma, 2) unresectable or recurrent gastric cancer, 3) peritoneal dissemination, 4) intolerance or refractory to first-line therapy including fluoropyrimidines, and 5) ECOG Performance Status (PS) 0-2. Patients are randomised to either arm at a 1:1 ratio stratified by institution, PS, and severity of ascites. PTX (80 mg/m2; days 1, 8, and 15) and RAM (8 mg/kg; days 1 and 15) are administered every 4 weeks in arm A, while nab-PTX (100 mg/m2; days 1, 8, and 15) instead of PTX is administered in arm B. The primary endpoint is OS, and the main secondary endpoints are PFS, objective response rate, safety, neuropathy-specific quality of life, and biomarkers. To maintain a probability of ≥70% to ensure the hazard ratio for OS in arm B is lower than 0.90, 105 subjects are required. The study was initiated in October 2018 and is being conducted in 58 centres of the West Japan Oncology Group.

DISCUSSION

The results of this study will determine whether w-nab-PTX plus RAM has the potential to be a preferred therapeutic option for advanced and recurrent gastric cancer with peritoneal dissemination, compared to wPTX plus RAM.

TRIAL REGISTRATION

This study was prospectively registered in the Japan Registry of Clinical Trials (jRCTs031180022, October 1, 2018).

Albumin-based cancer therapeutics for intraperitoneal drug delivery: a review

Albumin is a remarkable carrier protein with multiple cellular receptor and ligand binding sites, which are able to bind and transport numerous endogenous and exogenous compounds. The development of albumin-bound drugs is gaining increased importance in the targeted delivery of cancer therapy. Intraperitoneal (IP) drug delivery represents an attractive strategy for the local treatment of peritoneal metastasis (PM). PM is characterized by the presence of widespread metastatic tumor nodules on the peritoneum, mostly originating from gastro-intestinal or gynaecological cancers. Albumin as a carrier for chemotherapy holds considerable promise for IP delivery in patients with PM. Data from recent (pre)clinical trials suggest that IP albumin-bound chemotherapy may result in superior efficacy in the treatment of PM compared to standard chemotherapy formulations. Here, we review the evidence on albumin-bound chemotherapy with a focus on IP administration and its efficacy in PM.

Conversion Surgery for Gastric Cancer with Peritoneal Metastasis Based on the Diagnosis of Second-Look Staging Laparoscopy

BACKGROUND

Patients with positive peritoneal cytology (CY1) or peritoneal dissemination (P1) have significantly poor prognosis. We performed pre-therapeutic staging laparoscopy (SL) to diagnose peritoneal metastasis for patients with advanced gastric cancer. When peritoneal metastasis disappears by chemotherapy for patients with CY1 or P1, we have intention to perform conversion surgery (CS). This study aims to clarify the clinical significance of CS for such patients.

METHODS

We retrospectively analyzed clinical outcomes of 115 patients with advanced gastric cancer (large type 3, type 4, serosa-invasion) who underwent SL between 2005 and 2014. Disappearance of peritoneal metastasis was confirmed by second-look SL.

RESULTS

CY0P0, CY1P0, and P1 were found in 56, 26, and 33 patients, respectively. In patients with CY1P0, 12 patients (66.7%) underwent CS (R0) as peritoneal cytology turned negative. All cases received S-1-based regimens, with median five treatment courses. The survival of patients with CS was significantly longer than those without CS (median survival time (MST); 41 vs. 11 months, respectively, P < 0.001). We observed no difference in overall survival between patients who underwent CS and patients with CY0P0 at the first SL (P = 0.913). All patients with P1 received chemotherapy. As peritoneal metastasis of five patients (15.2%) disappeared by chemotherapy, those patients underwent the CS (R0). The survival of patients who underwent CS was significantly longer than those who did not (MST; 31 vs. 10 months, respectively, P = 0.034).

CONCLUSION

This study suggests that conversion surgery contributes to improvement in survival of patients with peritoneal metastasis.

Nanoparticle albumin-bound paclitaxel: a big nano for the treatment of gastric cancer

Gastric cancer (GC) is the third cause of cancer-related death worldwide. Patients with unresectable GC can be treated with chemotherapy such as paclitaxel, which is a microtubule stabilizer. The use of nanoparticle albumin-bound paclitaxel (nab-ptx) avoids hypersensitivity reactions due to the absence of solvent needed to dissolve paclitaxel and it can be administered at higher doses. The ABSOLUTE randomized phase-3 clinical trial showed the non-inferiority of the nab-ptx used every week compared to the solvent-based paclitaxel used every week. This review describes the current advancements of the use of nab-ptx in GC in preclinical and clinical study investigations. The possibility of combining nab-ptx with other medications to improve response of patients to their specific molecular needs will also be debated.

Evaluation of the Biological Behavior of a Gold Nanocore-Encapsulated Human Serum Albumin Nanoparticle (Au@HSANP) in a CT-26 Tumor/Ascites Mouse Model after Intravenous/Intraperitoneal Administration

Colorectal cancer is one of the major causes of cancer-related death in Taiwan and worldwide. Patients with peritoneal metastasis from colorectal cancer have reduced overall survival and poor prognosis. Hybrid protein-inorganic nanoparticle systems have displayed multifunctional applications in solid cancer theranostics. In this study, a gold nanocore-encapsulated human serum albumin nanoparticle (Au@HSANP), which is a hybrid protein-inorganic nanoparticle, and its radioactive surrogate ¹¹¹In-labeled Au@HSANP (¹¹¹In-Au@HSANP), were developed and their biological behaviors were investigated in a tumor/ascites mouse model. ¹¹¹In-Au@HSANP was injected either intravenously (iv) or intraperitoneally (ip) in CT-26 tumor/ascites-bearing mice. After ip injection, a remarkable and sustained radioactivity retention in the abdomen was noticed, based on microSPECT images. After iv injection, however, most of the radioactivity was accumulated in the mononuclear phagocyte system. The results of biodistribution indicated that ip administration was significantly more effective in increasing intraperitoneal concentration and tumor accumulation than iv administration. The ratios of area under the curve (AUC) of the ascites and tumors in the ip-injected group to those in the iv-injected group was 93 and 20, respectively. This study demonstrated that the ip injection route would be a better approach than iv injections for applying gold-albumin nanoparticle in peritoneal metastasis treatment.

Peritoneal metastasis as a predictive factor for nab-paclitaxel in patients with pretreated advanced gastric cancer: an exploratory analysis of the phase III ABSOLUTE trial

BACKGROUND

In the ABSOLUTE trial, weekly nanoparticle albumin-bound paclitaxel (w-nab-PTX) showed non-inferiority to weekly solvent-based paclitaxel (w-sb-PTX) for overall survival (OS). Thus, w-nab-PTX might be an option for second-line chemotherapy in advanced gastric cancer (AGC). However, predictive factors for efficacies of these agents have not been evaluated.

METHODS

Patients previously enrolled in the ABSOLUTE trial were divided into apparent peritoneal metastasis group (PM group) and no apparent peritoneal metastasis group (no PM group) based on baseline imaging evaluated by RECIST ver. 1.1 criteria and amount of ascites. OS, progression-free survival, and overall response rate were compared between two arms in each group.

RESULTS

This study included 240 and 243 patients in the w-nab-PTX and w-sb-PTX arms, respectively. In the PM group, the w-nab-PTX arm (n = 88) had longer OS than the w-sb-PTX arm (n = 103), and median survival time (MST) of 9.9 and 8.7 months [hazard ratio (HR) 0.63; 95% CI 0.45-0.88; P = 0.0060], respectively. In the no PM group, the w-nab-PTX arm (n = 140) had shorter OS than the w-sb-PTX arm (n = 152), and MST of 11.6 and 15.7 months (HR 1.40; 95% CI 1.06-1.86; P = 0.0180), respectively. After adjusting for prognostic factors, the HR for OS in the w-nab-PTX arm versus the w-sb-PTX arm was 0.59 (95% CI 0.42-0.83; P = 0.0023; PM group) and 1.34 (95% CI 1.01-1.78; P = 0.0414; no PM group), with significant interaction between treatment efficacy and presence of peritoneal metastasis (P = 0.0003).

CONCLUSIONS

The presence of apparent peritoneal metastasis might be a predictive factor for selecting w-nab-PTX for pretreated AGC patients.

TRIAL REGISTRATION NUMBER

JapicCTI-132059.

Reactive Oxygen Species (ROS)-Responsive Charge-Switchable Nanocarriers for Gene Therapy of Metastatic Cancer

The application of nonviral gene vectors has been limited by their insufficient transfection efficiency because of poor serum stability, high endosomal entrapment, limited intracellular release, and low accumulation in the targeted organelle. It is still challenging to design gene carriers with properties that can overcome all of the barriers. We previously developed a reactive oxygen species (ROS)-responsive cationic polymer, poly[(2-acryloyl)ethyl( p-boronic acid benzyl) diethylammonium bromide] (B-PDEAEA), which switches the charge at high concentrations of intracellular ROS to promote intracellular DNA release. However, its gene-delivery efficiency has been limited by serum instability and lysosomal trapping, and coating with an anionic PEGylated lipid only showed mild enhancement. Herein, we coated the ROS-responsive B-PDEAEA polymer with two cationic lipids to form ROS-responsive lipopolyplexes with integrated properties to overcome multiple delivery barriers. The surface cationic lipids endowed the nanocarrier with improved serum stability, effective cellular uptake, and lysosomal evasion. The interior B-PDEAEA/DNA polyplexes, which were highly stable in the extracellular environment, but quickly dissociated, released DNA, promoted nuclei localization, and achieved efficient transcription. The mechanisms of the ROS-responsive and charge-switchable properties of B-PDEAEA were quantitatively studied. The transfection efficiency and antitumor activity of lipopolyplexes were studied in vitro and in vivo. We found that the ROS-responsive lipopolyplexes effectively delivered therapeutic genes into cell nuclei and caused high tumor inhibition in mice bearing peritoneal or lung metastases.

Nanoformulated paclitaxel and AZD9291 synergistically eradicate non-small-cell lung cancers in vivo

AIM

This study aims to develop new nanoformulations of EGFR T790M targeted inhibitor AZD9291 and paclitaxel (PTX) for combination therapy of lung cancer.

MATERIALS & METHODS

We prepared and characterized PTX- and AZD9291-loaded disulfide cross-linking micelles (DCMs), and evaluate their combination effect and toxicity in vitro and in lung cancer-bearing mice.

RESULTS

Drug-loaded DCMs were relatively small in size, and possessed glutathione-responsive drug release. The combination of PTX-DCMs and AZD92921-DCMs exhibited strong synergistic effects in both cell line and in vivo without additional toxicity. Molecular studies demonstrated the synergistic modification in both IKB-α/NF-κB/Bcl-2 and EGFR/Akt pathways.

CONCLUSION

The combination of DCM-loaded AZD9291 and PTX could potentially offer more effective and less toxicity treatment options for lung cancer patients.

Treatment of patients with peritoneal metastases from gastric cancer

Despite recent advances in chemotherapy, outcomes of patients with peritoneal metastases (PM) from gastric cancer are still very poor and standard treatment has not been established. Although oral S‐1 appears to be effective for patients with PM, the effects of systemic chemotherapy are limited. Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) yield fewer benefits in patients with PM from gastric cancer than in patients with PM from other malignancies. In comparison, repeated intraperitoneal chemotherapy (RIPEC) with taxanes using an implantable peritoneal access port has a pharmacokinetic advantage for the control of peritoneal lesions and in combination with systemic chemotherapy can result in surprisingly long‐term survival in patients with PM from gastric cancer. Herein, we review the results of recent clinical studies specifically targeting PM from gastric cancer and discuss future prospects for an intraperitoneal approach to the ideal treatment of patients with gastric cancer with peritoneal involvement.

Systemic effects of angiogenesis inhibition alter pharmacokinetics and intratumoral delivery of nab-paclitaxel

Angiogenesis is critical to the growth of tumors. Vascularization-targeting agents, with or without cytotoxic drugs, are widely used for the treatment of several solid tumors including esophagogastric adenocarcinoma. However, little is known about the systemic effects of anti-angiogenic therapies and how this affects the pharmacokinetics and intratumoral delivery of cytotoxic agents. In this study, patient-derived xenograft mouse models of esophageal adenocarcinoma were used to identify the effects of DC101, a murine vascular endothelial growth factor receptor 2 (VEGFR2) inhibitor, on the pharmacokinetics and the intratumoral uptake of nab-paclitaxel (NPTX). We showed that DC101 had large systemic effects resulting in decreased vasculature of intraperitoneally located organs. As a consequence, after intraperitoneal administration of NPTX, plasma uptake (5.029 ± 4.35 vs. 25.85 ± 2.27 µM) and intratumoral delivery (5.48 ± 5.32 vs. 38.49 ± 2.805 pmol/mg) of NPTX were greatly impaired in DC101-treated animals compared to control animals. Additionally, routes of NPTX elimination were altered upon angiogenesis inhibition; unchanged renal clearance and intraperitoneal accumulation of NPTX were observed, but NPTX levels were significantly lower in the liver. Histological examination of the intestine revealed a reduced thickness of the intestinal wall following DC101 therapy and suggested seepage of intraperitoneally injected NTPX through the intestinal wall to explain its reduced uptake in liver, plasma, and tumor tissue. These data explain several adverse effects observed in the clinic when using anti-angiogenic therapies and also imply that the combined use of anti-angiogenesis and cytotoxic agents in both preclinical and clinical setting is still suboptimal.

Nanoparticle as a novel tool in hyperthermic intraperitoneal and pressurized intraperitoneal aerosol chemotheprapy to treat patients with peritoneal carcinomatosis

The treatment of peritoneal surface malignances has changed considerably over the last thirty years. Unfortunately, the palliative is the only current treatment for peritoneal carcinomatosis (PC). Two primary intraperitoneal chemotherapeutic methods are used. The first is combination of cytoreductive surgery (CRS) and Hyperthermic IntraPEritoneal Chemotherapy (HIPEC), which has become the gold standard for many cases of PC. The second is Pressurized IntraPeritoneal Aerosol Chemotheprapy (PIPAC), which is promising direction to minimally invasive as safedrug delivery. These methods were improved through multicenter studies and clinical trials that yield important insights and solutions. Major method development has been made through nanomedicine, specifically nanoparticles. Here, we are presenting the latest advances of nanoparticles and their application to precision diagnostics and improved treatment strategies for PC. These advances will likely develop both HIPEC and PIPAC methods that used for in vitro and in vivo studies. Several benefits of using nanoparticles will be discussed including: 1) Nanoparticles as drug delivery systems; 2) Nanoparticles and Near Infrred (NIR) Irradiation; 3) use of nanoparticles in perioperative diagnostic and individualized treatment planning; 4) use of nanoparticles as anticancer dressing's, hydrogels and as active beeds for optimal reccurence prevention; and 5) finally the curent in vitro and in vivo studies and clinical trials of nanoparticles. The current review highlighted use of nanoparticles as novel tools in improving drug delivery to be effective for treatment patients with peritoneal carcinomatosis.

Amphiphilic PEGylated Lanthanide-Doped Upconversion Nanoparticles for Significantly Passive Accumulation in the Peritoneal Metastatic Carcinomatosis Models Following Intraperitoneal Administration

Inorganic nanoparticles have emerged as attractive materials for cancer research, because of their exceptional physical properties and multifunctional engineering. However, inorganic nanoparticle accumulation in the tumors located in the abdominal cavity after intravenous (IV) administration is confined because of the peritoneum-plasma barrier. To improve this situation, we developed lanthanide-doped upconversion nanoparticles (UCNPs), coated by amphiphilic polyethylene glycol (P-PEG), serving as a representative of inorganic nanoparticles. Following intraperitoneal (IP) administration into the peritoneal metastatic carcinomatosis models, UCNPs coated by P-PEG (P-PEG-UCNPs) passively accumulated in the cancerous tissues at a larger amount than that in the main normal organs. On the basis of spatial proximity, P-PEG-UCNPs administrated via the IP route exhibited higher passive accumulation in the tumors in the abdominal cavity compared to that via the IV route. It is suggested that IP administration could be a promising strategy for inorganic nanoparticles to be efficaciously applied in peritoneal cancer research.

High Penetration of Paclitaxel in Abdominal Wall of Rabbits after Hyperthermic Intraperitoneal Administration of Nab-Paclitaxel Compared to Standard Paclitaxel Formulation

PURPOSE

Paclitaxel (PTX) is currently used in combination with cisplatin for Hyperthermic Intraperitoneal Chemotherapy (HIPEC) for the treatment of peritoneal carcinomatosis. Albumin-bound PTX is a promising new drug for HIPEC because of its easy solubility in aqueous perfusion medium and possibly because of the tendency of albumin to cross physiological barriers and accumulate in tumor tissue.

METHODS

We tested the feasibility of using nab-paclitaxel in rabbits treated by HIPEC for 60 min compared with the classical formulation at an equivalent PTX dose. Samples of perfusate and blood were collected at different time points and peritoneal tissues were collected at the end of perfusion. PTX concentrations were determined by HPLC. The depth of paclitaxel penetration through the peritoneal barrier was assessed by mass spectrometry imaging.

RESULTS

PTX after nab-paclitaxel treatment penetrated up to 0.63 mm in the peritoneal wall, but after CRE-paclitaxel, it was not detectable in the peritoneum. Moreover, the peritoneal concentration after nab-paclitaxel was five times that after paclitaxel classical formulation. Despite the high levels reached in the peritoneum, systemic exposure of PTX was low.

CONCLUSIONS

Our results show that nab-paclitaxel penetrates into the abdominal wall better than CRE-paclitaxel, in terms of effective penetration and peritoneal tissue concentration.

Nab-paclitaxel versus solvent-based paclitaxel in patients with previously treated advanced gastric cancer (ABSOLUTE): an open-label, randomised, non-inferiority, phase 3 trial

BACKGROUND

Weekly administration of solvent-based paclitaxel is one of the standard second-line chemotherapy regimens for advanced gastric cancer. Nanoparticle albumin-bound paclitaxel (nab-paclitaxel) was developed to improve the solubility of paclitaxel and does not need premedication to avoid infusion-related reactions associated with solvent-based paclitaxel. Additionally, higher doses of nab-paclitaxel can be administered over a shorter infusion time and at higher drug concentrations compared with solvent-based paclitaxel. We aimed to investigate the efficacy and safety of nab-paclitaxel versus solvent-based paclitaxel in patients with previously treated advanced gastric cancer.

METHODS

We did a randomised, open-label, non-inferiority, phase 3 trial at 72 institutions in Japan. Patients aged 20 years or older with advanced gastric adenocarcinoma refractory to a fluoropyrimidine-containing first-line chemotherapy regimen, with progressive disease or a relapse fewer than 24 weeks after the final dose of adjuvant chemotherapy were randomly assigned (1:1:1) to receive intravenous nab-paclitaxel (260 mg/m²) every 3 weeks (on day 1 of a 21-day cycle), weekly nab-paclitaxel (100 mg/m², on days 1, 8, and 15 of a 28-day cycle), or weekly solvent-based paclitaxel (80 mg/m², on days 1, 8, and 15 of a 28-day cycle). Randomisation was done with the minimisation method, with stratification for previous use of docetaxel, presence of peritoneal metastases, and Eastern Cooperative Oncology Group (ECOG) performance status. The primary endpoint was overall survival in the full analysis set, which included all randomly assigned patients who received at least one dose of study drug, with a non-inferiority margin of 1·25 for the hazard ratio. This trial is registered with Japan Pharmaceutical Information Center Clinical Trial, number JapicCTI-132059, and has been completed.

FINDINGS

Between March 13, 2013, and May 14, 2015, 741 patients were randomly assigned to nab-paclitaxel every 3 weeks (n=247), weekly nab-paclitaxel (n=246), or weekly solvent-based paclitaxel (n=248). Median follow-up for overall survival was 9·99 months (IQR 6·05-15·05). Median overall survival was 10·3 months (95% CI 8·7-11·4) in the group that received in the nab-paclitaxel every 3 weeks, 11·1 months (9·9-13·0) in the weekly nab-paclitaxel group, and 10·9 months (9·4-11·8) in the weekly solvent-based paclitaxel group. Weekly nab-paclitaxel was non-inferior to weekly solvent-based paclitaxel (hazard ratio 0·97, 97·5% CI 0·76-1·23; non-inferiority one-sided p=0·0085), whereas nab-paclitaxel every 3 weeks was not non-inferior to solvent-based paclitaxel (1·06, 95% CI 0·87-1·31; non-inferiority one-sided p=0·062). The main grade 3 or worse adverse drug reactions were neutropenia (158 [65%] of 244 patients in the group that received nab-paclitaxel every 3 weeks vs 99 [41%] of 241 patients in the weekly nab-paclitaxel group vs 71 [29%] of 243 patients in the weekly solvent-based paclitaxel group), peripheral sensory neuropathy (49 [20%] vs six [2%] vs six [2%]), and febrile neutropenia (30 [12%] vs seven [3%] vs two [1%]). Hypersensitivity reactions were less frequent with nab-paclitaxel every 3 weeks (two [1%] patients) and weekly nab-paclitaxel (three [1%] patients) than with weekly solvent-based paclitaxel (13 [5%] patients). Four treatment-related deaths were reported overall (pneumonia in one patient in the group that received nab-paclitaxel every 3 weeks, febrile neutropenia/pneumonia in one patient, and septic shock in one patient in the weekly nab-paclitaxel group, and respiratory disease/interstitial lung disease in one patient in the weekly solvent-based paclitaxel group).

INTERPRETATION

As the trial showed that weekly nab-paclitaxel was non-inferior to weekly solvent-based paclitaxel in terms of overall survival, the advantages of the nab-paclitaxel formulation make it a potential regimen for second-line treatment of gastric cancer.

FUNDING

Taiho Pharmaceutical.

Inhibitory effect of intraperitoneal chemotherapy with sustained-release fluorouracil vs fluorouracil injection on peritoneally transplanted MKN-45 tumors in nude mice

AIM

To compare the inhibitory effect of sustained-release fluorouracil (Sinofuan) and fluorouracil injection on peritoneally transplanted MKN-45 tumors in nude mice.

METHODS

Fifty-one nude mice peritoneally transplanted with MKN-45 cells were randomly divided into three groups: control group, fluorouracil injection group (2 mg/nude mouse), and sustained-release fluorouracil group (2 mg/nude mouse). The general status of the nude mice, body mass changes and survival were observed. Ascites volume was measured, the number of tumor cells per milliliter of ascites was counted, and tumor cell apoptosis was detected.

RESULTS

Compared with the control group, the general status of nude mice from the fluorouracil injection group and sustained-release fluorouracil group were better with regard to slower weight gain, delayed systemic symptoms and prolonged survival (P < 0.05). The median survival of mice in the sustained-release fluorouracil group was prolonged compared with the fluorouracil injection group (25 d vs 19 d, P < 0.01). Ascites volume in the sustained-release fluorouracil group was less than that in the fluorouracil injection group [(5.66 mL ± 1.00 mL) vs (8.78 mL ± 1.19 mL), P < 0.01], but the difference in the number of ascitic tumor cells per milliliter between the two groups was not statistically significant [(2.75 × 10⁸/mL ± 0.71 × 10⁸/mL) vs (3.46 × 10⁸/mL ± 0.69 × 10⁸/mL)]. Tumor cell apoptosis rate was significantly higher in the sustained-release fluorouracil group than in the fluorouracil injection group (14.49% ± 0.80% vs 2.03% ± 0.64%, P < 0.01).

CONCLUSION

Sustained-release fluorouracil is better than fluorouracil injection in intraperitoneal chemotherapy for peritoneally transplanted MKN-45 tumors in nude mice.