Phase II trial of pegylated-liposomal doxorubicin in the treatment of locally advanced unresectable or metastatic transitional cell carcinoma of the urothelial tract

A systematic review of nanocarriers for treatment of urologic cancers

Nanocarriers (NCs) are a form of nanotechnology widely investigated in cancer treatment to improve the safety and efficacy of systemic therapies by increasing tumor specificity. Numerous clinical trials have explored the use of NCs in urologic cancers since the approval of the first NCs for cancer treatment over 20 years ago. The objective of this systematic review is to examine the effectiveness and safety of NCs in treating urological cancers. This paper summarizes the state of the field by investigating peer-reviewed, published results from 43 clinical trials involving the use of NCs in bladder, prostate, and kidney cancer patients with a focus on safety and efficacy data. Among the 43 trials, 16 were phase I, 20 phase II, and 4 phase I/II. No phase III trials have been reported. While both novel and classic NCs have been explored in urologic cancers, NCs already approved for the treatment of other cancers were more widely represented. Trials in prostate cancer and mixed trials involving both urologic and non-urologic cancer patients were the most commonly reported trials. Although NCs have demonstrable efficacy with adequate safety in non-urologic cancer patient populations, current clinical stage NC options appear to be less beneficial in the urologic cancer setting. For example, nab-paclitaxel and liposomal doxorubicin have proven ineffective in the treatment of urologic cancers despite successes in other cancers. However, several ongoing pre-clinical studies using targeted and locally applied improved NCs may eventually improve their utility.

Increased endocytosis of magnetic nanoparticles into cancerous urothelial cells versus normal urothelial cells

The blood-urine barrier is the tightest and most impermeable barrier in the body and as such represents a problem for intravesical drug delivery applications. Differentiation-dependent low endocytotic rate of urothelial cells has already been noted; however, the differences in endocytosis of normal and cancer urothelial cells have not been exploited yet. Here we analysed the endocytosis of rhodamine B isothiocyanate-labelled polyacrylic acid-coated cobalt ferrite nanoparticles (NPs) in biomimetic urothelial in vitro models, i.e., in highly and partially differentiated normal urothelial cells, and in cancer cells of the papillary and invasive urothelial neoplasm. We demonstrated that NPs enter papillary and invasive urothelial neoplasm cells by ruffling of the plasma membrane and engulfment of NP aggregates by macropinocytotic mechanism. Transmission electron microscopy (TEM) and spectrophotometric analyses showed that the efficacy of NPs delivery into normal urothelial cells and intercellular space is largely restricted, while it is significantly higher in cancer urothelial cells. Moreover, we showed that the quantification of fluorescent NP internalization in cells or tissues based on fluorescence detection could be misleading and overestimated without TEM analysis. Our findings contribute to the understanding of endocytosis-mediated cellular uptake of NPs in cancer urothelial cells and reveal a highly selective mechanism to distinguish cancer and normal urothelial cells.

Nanotechnology in Urology

Introduction:

Nanotechnology has revolutionized our approach to medical diagnostics as well as therapeutics and has spanned an entirely new branch of research. This review addresses the potential applications of Nanotechnology in Urology. This article is based on the Dr. Sitharaman Best Essay award of the Urological Society of India for 2016.

Methods:

A PubMed search was performed for all relevant articles using the terms, “nanotechnology, nanoparticles, nanoshells, nanoscaffolds, and nanofibers.”

Results:

The developments in diagnostics include novel techniques of imaging of genitourinary malignancies, prostate-specific antigen measurement, early detection of mutations that are diagnostic for polycystic kidney disease. The potential applications of nanotechnology are in the targeted therapy of genitourinary malignancies, erectile dysfunction, overactive bladder, bladder reconstruction, construction of artificial kidneys and biodegradable stents as well as in robotic surgery.

Conclusions:

Nanotechnology is a rapidly emerging branch of research in urology with diverse and clinically significant applications in diagnostics as well as therapeutics.

Styrene maleic acid copolymer-pirarubicin induces tumor-selective oxidative stress and decreases tumor hypoxia as possible treatment of colorectal cancer liver metastases

BACKGROUND

Pirarubicin, a derivative of doxorubicin, induces tumor destruction via the production of reactive oxygen species (ROS) but is associated with cardiotoxicity. As a macromolecule (conjugated to styrene-maleic acid [SMA]), SMA-pirarubicin is selective to tumors resulting in improved survival with decreased systemic toxicity. Tumor destruction is, however incomplete, and resistant cells at the periphery of the tumor contribute to recurrence. Tumor hypoxia is a major factor in tumor resistance. Understanding the effect of oxidative stress induced by SMA-pirarubicin on the tumor microenvironment may be key to overcoming resistance. This study investigated the pattern of ROS production and tumor hypoxia after treatment with SMA-pirarubicin in a murine model of colorectal liver metastases.

METHODS

Liver metastases were induced in male, CBA mice using a murine-derived colon cancer cell line. SMA-pirarubicin (maximum tolerated dose, 100 mg/kg) or pirarubicin, (maximum tolerated dose, 10 mg/kg) were administered intravenously 14 days after tumor induction. Systemic oxidative stress in serum, liver, and cardiac tissue was quantified using the thiobarbituric acid reactive substances assay. Flow cytometry and fluorescence microscopy were used to assess ROS production for 48 hours after treatment. Tumor hypoxia was quantified using immunohistochemistry for pimonidazole adducts.

RESULTS

SMA-pirarubicin (100 mg/kg) induced ROS exclusively in tumors with minimal levels in serum and cardiac tissue. ROS levels were induced in a time-dependent and dose-dependent manner optimal between 4 and 24 hours after drug administration. Although tumor hypoxia was decreased overall, residual tumor cells adjacent to patent vessels were hypoxic.

CONCLUSION

This study provides insight into the tumor microenvironment after chemotherapy. SMA-pirarubicin inhibits the growth of colorectal liver metastases by inducing ROS, which seems to be largely tumor selective. The temporal pattern of ROS production can be used to improve future dosing regimens. Furthermore, the observation that residual tumor cells are hypoxic clarifies the need for a multimodal approach with agents that can alter the hypoxic state to effect complete tumor destruction.

Pegylated liposomal doxorubicin as third-line chemotherapy in patients with metastatic transitional cell carcinoma of urothelial tract: results of a phase II study

Until the recent approval of vinflunine, no standard second-line chemotherapy existed for advanced transitional cell carcinoma (TCC). Few data exist about third-line chemotherapy for metastatic disease. Although administered in up-front regimens, anthracyclines were never evaluated beyond second-line treatment. This study assessed the activity of pegylated liposomal doxorubicin (PLD) in patients with advanced TCC previously treated with two chemotherapy regimens. From May 2005 to June 2009, 23 patients with metastatic TCC were recruited: median age was 62 years (49-76 years) with a median ECOG PS of 1. Patients received PLD 35 mg/m(2) every 21 days. All patients were evaluable for efficacy and toxicity. No patient showed complete response. Three patients (13 %) had partial response; seven patients (30 %) showed stable disease for a disease control rate of 43 %. The median time to progression (TTP) was 4.1 months with a median survival time (MST) of 6.3 months. Treatment was well tolerated: no patient developed grade 4 toxicities. This is the first study which evaluated the role of anthracyclines as third-line chemotherapy in metastatic TCC. Despite its manageable profile of toxicity, PLD showed modest activity. Beyond second-line chemotherapy, supportive care still represents the best therapeutic option for patients with metastatic TCC.

Tumor-targeting multifunctional micelles for imaging and chemotherapy of advanced bladder cancer

AIM

This work aimed to determine if the treatment outcomes of bladder cancer could be improved by targeting micelles that are decorated with bladder cancer-specific ligands on the surface and loaded with the chemotherapeutic drug paclitaxel.

MATERIALS & METHODS

Targeting efficacy and specificity was determined with cell lines. An in vivo targeting and anti-tumor efficacy study was conducted in mice carrying patient-derived xenografts.

RESULTS & DISCUSSION

Targeting micelles were more efficient than nontargeting micelles in delivering the drug load into bladder cancer cells both in vitro and in vivo (p < 0.05). The micelle formulation of paclitaxel was less toxic than free paclitaxel in Cremophor(®) (Sigma, MO, USA) and allowed administration of three-times the maximum tolerated dose without increasing the toxicity. Targeting micelles were more effective than the nontargeting micelles in controlling cancer growth (p = 0.0002) and prolonging overall survival (p = 0.002).

CONCLUSION

Targeting micelles loaded with paclitaxel offer strong potential for clinical applications in treating bladder cancer.

Nanotechnology in urology

Nanomedicine is a new distinct scientific discipline that explores applications of nanoscale materials for various biomedical applications. Translational nanomedicine is undergoing rapid transition from development and evaluation in laboratory animals to clinical practices. In the future, it is anticipated that nanotechnology can provide urologists a new point of view to understand the mechanism of disease, tools for early diagnosis of the disease, and effective modality for treatment. This article summarizes some of the emerging applications of nanomedicine in urology.

Radical hypofractionated accelerated radiotherapy with cytoprotection for invasive bladder cancer

OBJECTIVES

To report a series of patients with bladder cancer treated with hypofractionated accelerated radiotherapy with amifostine cytoprotection, with or without concurrent liposomal doxorubicin. Radiochemotherapy has been shown to be an effective alternative to cystectomy.

METHODS

A total of 38 patients with invasive bladder cancer were treated with 15 consecutive fractions of 3.4 Gy (2.7 Gy to the pelvis and a 0.7-Gy concomitant boost to the bladder; total biologic dose 66 to 72 Gy in 19 days). An individualized amifostine dose of up to 1000 mg was given subcutaneously before each radiotherapy fraction. Nineteen patients received concomitant liposomal doxorubicin (25 mg/m2 every 2 weeks for six cycles).

RESULTS

Of the 38 patients, 33 tolerated a daily amifostine dose of 750 to 1000 mg well. For these patients, the acute radiation toxicity in the bladder and rectum was minimal. Liposomal doxorubicin did not increase radiation sequela and had no systemic side effects. At a median follow-up of 22 months, severe late sequelae were infrequent (5.5% dysuria grade 2, 7.8% frequency grade 1, and 2.8% incontinence grade 2). Cystoscopy confirmed significant bladder shrinkage in 8% of patients. Intermittent rectal urgency was noted in only 5.5% of patients. A complete response was obtained in 32 (84.2%) of 38 patients. Despite the 10% greater complete response rate noted in patients receiving chemotherapy, the difference did not reach statistical significance. The 2-year local relapse-free survival rate was 80%.

CONCLUSIONS

Hypofractionated accelerated radiotherapy with amifostine cytoprotection with or without concomitant liposomal doxorubicin provided high control rates of bladder cancer with low toxicity, and also had the advantage of reducing by 4 weeks the overall treatment time compared with standard radiotherapy.

Efficacy and safety of liposomal anthracyclines in Phase I/II clinical trials

Preclinical studies have established the pharmacologic advantages of liposomal anthracyclines, including pharmacokinetic profiles after bolus dosing that resemble continuous infusion of conventional anthracyclines, increased drug concentrations in tumor cells compared with the surrounding tissues, and reduced toxicity relative to conventional anthracycline treatment. Based on these studies, many phase I and phase II clinical trials were conducted to assess the safety and potential activity of liposomal anthracyclines in the management of both solid and hematologic tumors. These studies provided valuable insight into the safety of pegylated liposomal doxorubicin (Doxil/Caelyx [PLD]), nonpegylated liposomal doxorubicin (Myocet [NPLD]), and liposomal daunorubicin (DaunoXome [DNX]) over a range of doses, either as single-agent therapy or in combination with other cytotoxic agents. Other liposomal anthracyclines in development may be well tolerated but their activity remains to be elucidated by clinical trials. The available data also suggest that liposomal anthracyclines have activity not only against tumor types with known sensitivity to conventional anthracyclines, but also potentially for tumors that are typically anthracycline-resistant. Despite the availability of clinical data from a wide variety of tumor types and patient populations, further studies of liposomal anthracycline therapy are needed to fully establish their safety, efficacy, and dosing in the treatment of these patients.