Pegylated liposomal doxorubicin and gemcitabine in the front-line treatment of recurrent/metastatic breast cancer: a multicentre phase II study

Pegylated liposomal doxorubicin (Duomeisu®) monotherapy in patients with HER2-negative metastatic breast cancer heavily pretreated with anthracycline and taxanes: a single-arm, phase II study

PURPOSE

To evaluate the efficacy and safety of pegylated liposomal doxorubicin (PLD) in patients with human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer (MBC) heavily pretreated with anthracycline and taxanes.

METHODS

In this single-arm, phase II study, patients with HER2-negative MBC previously treated with anthracycline and taxanes as second- to fifth chemotherapy received PLD (Duomeisu^®, generic doxorubicin hydrochloride liposome) 40 mg/m² every 4 weeks until disease progression, unacceptable toxicity, or completion of six cycles. Primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS), objective response rate (ORR), disease control rate (DCR), clinical benefit rate (CBR), and safety.

RESULTS

Of 44 enrolled patients (median age, 53.5 years; range, 34-69), 41 and 36 were evaluable for safety and efficacy, respectively. In total, 59.1% (26/44) of patients had ≥ 3 metastatic sites, 86.4% (38/44) had visceral disease, and 63.6% (28/44) had liver metastases. Median PFS was 3.7 months (95% confidence interval [CI] 3.3-4.1) and median OS was 15.0 months (95% CI 12.1-17.9). ORR, DCR, and CBR were 16.7%, 63.9%, and 36.1%, respectively. The most common adverse events (AEs) were leukopenia (53.7%), fatigue (46.3%), and neutropenia (41.5%), with no grade 4/5 AEs. The most common grade 3 AEs were neutropenia (7.3%) and fatigue (4.9%). Patients experienced palmar-plantar-erythrodysesthesia (24.4%, 2.4% grade 3), stomatitis (19.5%, 7.3% grade 2), and alopecia (7.3%). One patient displayed a left ventricular ejection fraction decline of 11.4% from baseline after five cycles of PLD therapy.

CONCLUSION

PLD (Duomeisu^®) 40 mg/m² every 4 weeks was effective and well-tolerated in patients with HER2-negative MBC heavily pretreated with anthracycline and taxanes, revealing a potentially viable treatment option for this population. Trial registration Chinese Clinical Trial Registry: ChiCTR1900022568.

Optimized 5-Fluorouridine Prodrug for Co-Loading with Doxorubicin in Clinically Relevant Liposomes

Liposome-based drug delivery systems have allowed for better drug tolerability and longer circulation times but are often optimized for a single agent due to the inherent difficulty of co-encapsulating two drugs with differing chemical profiles. Here, we design and test a prodrug based on a ribosylated nucleoside form of 5-fluorouracil, 5-fluorouridine (5FUR), with the final purpose of co-encapsulation with doxorubicin (DOX) in liposomes. To improve the loading of 5FUR, we developed two 5FUR prodrugs that involved the conjugation of either one or three moieties of tryptophan (W) known respectively as, 5FUR−W and 5FUR−W₃. 5FUR−W demonstrated greater chemical stability than 5FUR−W3 and allowed for improved loading with fewer possible byproducts from tryptophan hydrolysis. Varied drug ratios of 5FUR−W: DOX were encapsulated for in vivo testing in the highly aggressive 4T1 murine breast cancer model. A liposomal molar ratio of 2.5 5FUR−W: DOX achieved a 62.6% reduction in tumor size compared to the untreated control group and a 33% reduction compared to clinical doxorubicin liposomes in a proof-of-concept study to demonstrate the viability of the co-encapsulated liposomes. We believe that the new prodrug 5FUR−W demonstrates a prodrug design with clinical translatability by reducing the number of byproducts produced by the hydrolysis of tryptophan, while also allowing for loading flexibility.

Anticancer and cardio-protective effects of liposomal doxorubicin in the treatment of breast cancer

Breast cancer (BC) is a highly prevalent disease, accounting for the second highest number of cancer-related mortalities worldwide. The anthracycline doxorubicin (DOX), isolated from Streptomyces peucetius var. caesius, is a potent chemotherapeutic drug that is successfully used to treat various forms of liquid and solid tumors and is currently approved to treat BC. DOX exerts its effects by intercalation into DNA and inhibition of topoisomerases I and II, causing damage to DNA and the formation of reactive oxygen species (ROS), resulting in the activation of caspases, which ultimately leads to apoptosis. Unfortunately, DOX also can cause cardiotoxicity, with patients only allowed a cumulative lifetime dose of 550 mg/m². Efforts to decrease cardiotoxicity and to increase the blood circulation time of DOX led to the US Food and Drug Administration (FDA) approval of a PEGylated liposomal formulation (L-DOX), Doxil^® (known internationally as Caelyx^®). Both exhibit better cardiovascular safety profiles; however, they are not currently FDA approved for the treatment of metastatic BC. Here, we provide detailed insights into the mechanism of action of L-DOX and its most common side effects and highlight results of its use in clinical trials for the treatment of BC as single agent and in combination with other commonly used chemotherapeutics.

Schedule dependent synergy of gemcitabine and doxorubicin: Improvement of in vitro efficacy and lack of in vitro-in vivo correlation

Combination chemotherapy is commonly used to treat late stage cancer; however, treatment is often limited by systemic toxicity. Optimizing drug ratio and schedule can improve drug combination activity and reduce dose to lower toxicity. Here, we identify gemcitabine (GEM) and doxorubicin (DOX) as a synergistic drug pair in vitro for the triple negative breast cancer cell line MDA‐MB‐231. Drug synergy and caspase activity were increased the most by exposing cells to GEM prior to DOX in vitro. While the combination was more effective than the single drugs at inhibiting MDA‐MB‐231 growth in vivo, the clear schedule dependence observed in vitro was not observed in vivo. Differences in drug exposure and cellular behavior in vivo compared to in vitro are likely responsible. This study emphasizes the importance in understanding how schedule impacts drug synergy and the need to develop more advanced strategies to translate synergy to the clinic.

Combination of pegylated liposomal doxorubicin plus gemcitabine in heavily pretreated metastatic breast cancer patients: Long-term results from a single institution experience

The combination of Pegylated Liposomal Doxorubicin (PLD) plus Gemcitabine (GEM) has been previously investigated in the treatment of metastatic breast cancer (MBC). PLD is a doxorubicin formulation with prolonged circulation time and better tissue distribution. GEM is a nucleoside analog with nonoverlapping toxicity compared to PLD. The aim of our study was to assess efficacy, toxicity, and long-term outcome of this combination. Patients with heavily treated MBC were retrospectively analyzed. Chemotherapy consisted of PLD 25 mg/m² and GEM 800 mg/m² day 1, on a three-week schedule. Cardiac function was evaluated baseline and during treatment. Radiological response was graded according to RECIST criteria v1.1. Toxicity was scored according to CTCAE v4.0. Progression-free survival (PFS) and overall survival (OS) were evaluated. From 2001 to 2014, 122 pts were included. Median age was 55 (range: 28-84). Median previous treatment schedules in the metastatic scenario were 3 (range: 1-15). Most patients received prior anthracyclines (85%). Median number of metastatic sites was 2 (range: 1-7). Median number of cycles delivered was 5 (range: 1-36). Overall response rate was 31% (5% complete responses; 26% partial responses). Stable and progressive diseases were observed in 32% and 26% of patients. Grade ≥3 neutropenia was observed in 29 patients (24%). Grade ≥3 hand-foot syndrome was detected in 17 patients (14%), mostly since cycle 3 (88%). Median cumulative PLD dose was 125 mg/m² . At a median follow-up of 101 months, median PFS and OS were 7 and 22 months, respectively. PLD-GEM combination achieves remarkable long-term outcomes with an acceptable toxicity profile in patients with MBC.

Protein-gold clusters-capped mesoporous silica nanoparticles for high drug loading, autonomous gemcitabine/doxorubicin co-delivery, and in-vivo tumor imaging

Functional nanocarriers capable of transporting high drug contents without premature leakage and to controllably deliver several drugs are needed for better cancer treatments. To address this clinical need, gold cluster bovine serum albumin (AuNC@BSA) nanogates were engineered on mesoporous silica nanoparticles (MSN) for high drug loadings and co-delivery of two different anticancer drugs. The first drug, gemcitabine (GEM, 40wt%), was loaded in positively-charged ammonium-functionalized MSN (MSN-NH3(+)). The second drug, doxorubicin (DOX, 32wt%), was bound with negatively-charged AuNC@BSA electrostatically-attached onto MSN-NH3(+), affording highly loaded pH-responsive MSN-AuNC@BSA nanocarriers. The co-delivery of DOX and GEM was achieved for the first time via an inorganic nanocarrier, possessing a zero-premature leakage behavior as well as drug loading capacities seven times higher than polymersome NPs. Besides, unlike the majority of strategies used to cap the pores of MSN, AuNC@BSA nanogates are biotools and were applied for targeted red nuclear staining and in-vivo tumor imaging. The straightforward non-covalent combination of MSN and gold-protein cluster bioconjugates thus leads to a simple, yet multifunctional nanotheranostic for the next generation of cancer treatments.

Uncommon breast metastatic site and eribulin responsiveness in a heavily pretreated patient

During the last decades, the introduction of new cytotoxics and targeted therapies resulted in a prolongation of survival and a minimization of toxicity in the treatment of metastatic breast cancer. However, to date, there was no standard of care following second-line therapy in this setting. In Phase III EMBRACE study, eribulin obtained a statistically significant improvement in the overall survival of pretreated metastatic breast cancer patients. This case report describes a heavily chemo-pretreated woman with important bone, nodal, hepatic and choroidal involvement from breast cancer who had a remarkable, unexpected and lasting disease response after treatment with eribulin. This case underlines how this well-tolerated monochemotherapy may be able to obtain a prolonged disease control and a good clinical outcome.

PEGylated liposomal Gemcitabine: insights into a potential breast cancer therapeutic

PURPOSE

Nanoencapsulation of chemotherapeutics is an established method to target breast tumors and has been shown to enhance the efficacy of therapy in various animal models. During the past two decades, the nucleoside analog Gemcitabine has been under investigation to treat both recalcitrant and localized breast cancer, often in combination with other chemotherapeutics. In this study, we investigated the chemotherapeutic efficacy of a novel Gemcitabine-encapsulated liposome previously formulated by our group, GemPo, on both sensitive (4T1) and recalcitrant (MDA-MB-231) breast cancer cell lines.

METHODS

Gemcitabine free drug and liposomal Gemcitabine were compared both in vitro and in vivo using breast cancer models.

RESULTS

We demonstrated that GemPo differently hindered the growth, survival and migration of breast cancer cells, according to their drug sensitivities. Specifically, whereas GemPo was a more potent cytotoxic and apoptotic agent in sensitive breast cancer cells, it more potently inhibited cell migration in the resistant cell line. However, GemPo still acted as a more potent inhibitor of migration, in comparison with free Gemcitabine, irrespective of cell sensitivity. Administration of GemPo in a 4T1-bearing mouse model inhibited tumor growth while increasing mice survival, as compared with free Gemcitabine and a vehicle control. Interestingly, the inclusion of a mitotic inhibitor, Paclitaxel, synergized only with free Gemcitabine in this model, yet was as effective as GemPo alone. However, inclusion of Paclitaxel with GemPo significantly improved mouse survival.

CONCLUSIONS

Our study is the first to demonstrate the pleiotropic effects of Gemcitabine and Gemcitabine-loaded nanoparticles in breast cancer, and opens the door for a novel treatment for breast cancer patients.

Inhibitory effect of geraniol in combination with gemcitabine on proliferation of BXPC-3 human pancreatic cancer cells

Objective

To investigate the inhibitory effect of geraniol alone, or in combination with gemcitabine, on the proliferation of BXPC-3 pancreatic cancer cells.

Methods

BXPC-3 cells were treated under different conditions: with geraniol at 10, 20, 40, 80 and 160 µmol/l each for 24 h, 48 h or 72 h; with 20 µmol/l geraniol for 24 h or 0 h before 20 µmol/l gemcitabine for 24 h; with 20 µmol/l geraniol for 24 h, 48 h and 72 h following 20 µmol/l gemcitabine for 24 h; or with 20 µmol/l gemcitabine alone as a control. Cell proliferation was assessed and changes in cell morphology were assessed by light and fluorescence microscopy. Apoptosis was detected using flow cytometry.

Results

Geraniol inhibited BXPC-3 cell proliferation in a time- and dosa-dependent manner. Geraniol alone or combined with gemcitabine induced BXPC-3 cell apoptosis. BXPC-3 inhibition rates with combined treatment were 55.24%, 50.69%, 49.83%, 41.85% and 45.27% following treatment with 20 µmol/l geraniol for 24 h or 0 h before 20 µmol/l gemcitabine for 24 h, or 20 µmol/l geraniol for 24 h, 48 h and 72 h, following 20 µmol/l gemcitabine for 24 h, respectively.

Conclusion

Geraniol inhibited the proliferation of BXPC-3 cells. Geraniol significantly increased the antiproliferative and apoptosis-inducing effects of gemcitabine on BXPC-3 cells. Maximum inhibition of BXPC-3 cells was achieved with geraniol treatment for 24 h before gemcitabine treatment.

Activity of pegylated liposomal doxorubicin in combination with gemcitabine in triple negative breast cancer with skin involvement: two case reports

Breast carcinoma (BC) is a heterogeneous disease in terms of histology, therapeutic response, dissemination patterns to distant sites and patient outcomes. Triple-negative breast cancer (TNBC), defined by the lack of protein expression of estrogen and progesterone receptors and the absence of HER2 protein overexpression (ER-/PR-/HER2-) has significant clinical implications due to their poor prognosis and the lack of targeted agents. Skin involvement is one of the most distressing presentations of locally recurrent breast cancer and few studies have identified effective agents in this setting. In fact, the increasing use of anthracycline/taxane-based chemotherapy in the neoadjuvant and/or adjuvant settings has led to investigate new cytotoxic therapies such as the combination of pegylated liposomal doxorubicin (PLD) with gemcitabine. Here, we report two cases of disseminated TNBC with extensive cutaneous metastases and a remarkable response to PLD in combination with gemcitabine. Further investigations are needed to confirm the efficacy of this regimen in skin involvement and TNBC.

Pegylated liposomal doxorubicin plus carboplatin in patients with metastatic breast cancer: a phase II study

BACKGROUND

We determined the objective response rates produced by pegylated liposomal doxorubicin (PLD) plus carboplatin with/without trastuzumab (Herceptin).

PATIENTS AND METHODS

Patients with measurable disease were stratified by taxane treatment history and human epidermal growth factor receptor-2 status.

TREATMENT

PLD 30 mg/m(2) followed by carboplatin, day 1 of each 28-day cycle; human epidermal growth factor receptor-2 (HER2)-positive patients also received trastuzumab.

RESULTS

Arm 1 received PLD plus carboplatin (N = 41 arm 1a, taxane naive; N = 42 arm 1b, taxane pretreated); Arm 2 patients received PLD plus carboplatin + Herceptin (N = 46). Overall response rates: 31%, 31%, and 56%, respectively. Median overall survival durations were not reached in arm 1a and were 13 and 33 months for arms 1b and 2. Median progression-free survival: 8, 5, 10 months, respectively. Grades 3-4 treatment-related toxic effects for arms 1a, 1b, 2, respectively, were neutropenia 22%, 31%, 35%; thrombocytopenia 34%, 26%, 17%; and fatigue 2%, 14%, 13%.

CONCLUSIONS

PLD plus carboplatin has moderate antitumor activity and excellent tolerability. Herceptin and PLD plus carboplatin in HER2-positive patients have antitumor activity without significant cardiac toxicity. Toxicity results suggest that PLD can be combined with Herceptin with minimal cardiac toxicity.

Doxorubicin as a molecular nanotheranostic agent: effect of doxorubicin encapsulation in micelles or nanoemulsions on the ultrasound-mediated intracellular delivery and nuclear trafficking

Doxorubicin (DOX) is one of the most commonly used chemotherapeutic drugs and is a popular research tool due to the inherent fluorescence of the DOX molecule. After DOX injection, fluorescence imaging of organs or cells can provide information on drug biodistribution. Therapeutic and imaging capabilities combined in a DOX molecule make it an excellent theranostic agent. However, DOX fluorescence depends on a number of factors that should be taken into consideration when interpreting results of DOX fluorescence measurements. Discussing these problems is the main thrust of the current paper. The sensitivity of DOX fluorescence intensity to DOX concentration, local microenvironment, and interaction with model cellular components is illustrated by fluorescence spectra of paired DOX/phospholipid, DOX/histone, DOX/DNA, and triple DOX/histone/DNA and DOX/phospholipid/DNA systems. DOX fluorescence is dramatically quenched upon intercalation into the DNA; DOX fluorescence is also self-quenched at high concentrations of molecularly dissolved DOX; in contrast, DOX fluorescence is increased after binding to the histone or partitioning into the phospholipid phase of PEG-phospholipid micelles or hydrophobic cores of polymeric micelles. While flow cytometry is commonly used for characterization of DOX intracellular uptake, the above aspects of DOX fluorescence may significantly complicate interpretation of flow cytometry results. High cell fluorescence measured by flow cytometry may provide deceptive information on the actual intracellular DOX concentration and may not correlate with the therapeutic efficacy if DOX does not penetrate into the site of action in cell nuclei. These problems are illustrated in the experiments on the intracellular trafficking of DOX encapsulated in poly(ethylene glycol)-co-polycaprolactone (PEG-PCL) micelles or PEG-PCL stabilized perfluorocarbon nanodroplets, with and without the application of ultrasound used as an external trigger. For efficient encapsulation in micelle cores, DOX is usually deprotonated, which removes the positive charge and enhances hydrophobicity of DOX molecule. It was found that the deprotonated DOX accumulated in the cell cytoplasm but did not penetrate into the cell nuclei. The same was true for the DOX encapsulated in micelles or nanodroplets, which may explain their low therapeutic efficacy in the absence of ultrasound. Ultrasound triggers DOX trafficking into the cell nuclei, which is especially pronounced in the presence of nanoemulsions that convert into microbubbles under the ultrasound action. Microbubble cavitation results in the transient permeabilization of both plasma and nuclear membranes, thus allowing DOX penetration into the cell nuclei, which dramatically enhances therapeutic efficacy of DOX-loaded nanodroplet systems.

New approaches in the management of advanced breast cancer - role of combination treatment with liposomal doxorubicin

Metastatic breast cancer (MBC) remains a major cause of morbidity and mortality in women worldwide. For three decades doxorubicin, alone or in combination with other cytotoxic agents, has been a mainstay of systemic therapy for MBC. However, its use is limited by cumulative cardiotoxicity. More recently liposomal formulations of doxorubicin have been developed which exhibit equal efficacy but reduced cardiotoxicity in comparison to conventional doxorubicin. The novel toxicity profile of liposomal doxorubicins has prompted their evaluation with various cytotoxic agents in patients with MBC. In addition, their favorable cardiac safety profile has prompted re-evaluation of concomitant therapy with doxorubicin and trastuzumab, a regimen of proven efficacy in MBC but previously considered to be associated with significant cardiotoxicity. We review clinical trial data addressing combination therapy with both pegylated and non-pegylated liposomal doxorubicin in patients with MBC.

Simultaneous delivery of doxorubicin and gemcitabine to tumors in vivo using prototypic polymeric drug carriers

Copolymers of N-(2-hydroxypropyl)methacrylamide (HPMA) are prototypic and well-characterized polymeric drug carriers that have been broadly implemented in the delivery of anticancer therapeutics. To demonstrate that polymers, as liposomes, can be used for simultaneously delivering multiple chemotherapeutic agents to tumors in vivo, we have synthesized and evaluated an HPMA-based polymer-drug conjugate carrying 6.4wt% of gemcitabine, 5.7wt% of doxorubicin and 1.0mol% of tyrosinamide (to allow for radiolabeling). The resulting construct, i.e. poly(HPMA-co-MA-GFLG-gemcitabine-co-MA-GFLG-doxorubicin-co-MA-TyrNH(2)), was termed P-Gem-Dox, and was shown to effectively kill cancer cells in vitro, to circulate for prolonged period of time, to localize to tumors relatively selectively, and to inhibit tumor growth. As compared to control regimens, P-Gem-Dox increased the efficacy of the combination of gemcitabine and doxorubicin without increasing its toxicity, and it more strongly inhibited angiogenesis and induced apoptosis. These findings demonstrate that passively tumor-targeted polymeric drug carriers can be used for delivering two different chemotherapeutic agents to tumors simultaneously, and they thereby set the stage for more elaborate analyses on the potential of polymer-based multi-drug targeting.