Lack of vesicant injury following extravasation of liposomal doxorubicin

Extravasation accidents with liposomal/liposomal pegylated anthracyclines treated with dexrazoxane: an overview and outcomes

The extravasation of chemotherapeutic agents is a challenge for oncologic care teams. The management of nonliposomal (conventional) anthracyclines is well established in clinical practice guidelines, including general measures and specific antidotes, such as dexrazoxane. However, there is little scientific evidence on the management of liposomal and pegylated liposomal anthracyclines. The aim of this paper was to review the scientific literature on the extravasation of liposomal and pegylated liposomal anthracyclines and determine the clinical impact of this type of extravasation, focusing on dexrazoxane. The literature was searched using two databases: PubMed and Embase. Three searches were conducted, using liposomal anthracycline extravasation, pegylated liposomal anthracycline extravasation, and liposomal doxorubicin extravasation as keywords, respectively. Seven articles fulfilled the study eligibility criteria and included seventeen cases in humans. Extravasation occurred with three drugs: liposomal doxorubicin in nine (53%) patients, liposomal daunorubicin in four (23.5%) patients, and pegylated liposomal doxorubicin in four (23.5%) patients. General measures for extravasations were applied in all patients, but only three patients received dexrazoxane. All cases were completely resolved at 2-3 months, except for one patient, in whom dexrazoxane was not used. In animals, dexrazoxane decreased both the frequency of wounds produced by pegylated liposomal doxorubicin and their extent. The pharmacokinetic profiles of liposomal and pegylated liposomal anthracyclines differ from those of conventional anthracyclines, modifying their effectiveness and safety. General measures may be inadequate to heal areas affected by extravasation, which may require the administration of dexrazoxane. However, each case should be evaluated individually for the administration of dexrazoxane in off-label use until scientific evidence is available on its effectiveness and safety as an antidote for these formulations of anthracyclines.

From Conventional to Stealth Liposomes a new Frontier in Cancer Chemotherapy

Many attempts have been made to achieve good selectivity to targeted tumor cells by preparing specialized carrier agents that are therapeutically profitable for anticancer therapy. Among these, liposomes are the most studied colloidal particles thus far applied in medicine and in particular in antitumor therapy. Although they were first described in the 1960s, only at the beginning of 1990s did the first therapeutic liposomes appear on the market. The first-generation liposomes (conventional liposomes) comprised a liposome-containing amphotericin B, Ambisome (Nexstar, Boulder, CO, USA), used as an antifungal drug, and Myocet (Elan Pharma Int, Princeton, NJ, USA), a doxorubicin-containing liposome, used in clinical trials to treat metastatic breast cancer. The second-generation liposomes (“pure lipid approach”) were long-circulating liposomes, such as Daunoxome, a daunorubicin-containing liposome approved in the US and Europe to treat AIDS-related Kaposi's sarcoma. The third-generation liposomes were surface-modified liposomes with gangliosides or sialic acid, which can evade the immune system responsible for removing liposomes from circulation. The fourth-generation liposomes, pegylated liposomal doxorubicin, were called “stealth liposomes” because of their ability to evade interception by the immune system, in the same way as the stealth bomber was able to evade radar. Actually, the only stealth liposome on the market is Caelyx/Doxil (Schering-Plough, Madison NJ, USA), used to cure AIDS-related Kaposi's sarcoma, resistant ovarian cancer and metastatic breast cancer. Pegylated liposomal doxorubicin is characterized by a very long-circulation half-life, favorable pharmacokinetic behavior and specific accumulation in tumor tissues. These features account for the much lower toxicity shown by Caelyx in comparison to free doxorubicin, in terms of cardiotoxicity, vesicant effects, nausea, vomiting and alopecia. Pegylated liposomal doxorubicin also appeared to be less myelotoxic than doxorubicin. Typical forms of toxicity associated to it are acute infusion reaction, mucositis and palmar plantar erythrodysesthesia, which occur especially at high doses or short dosing intervals. Active and cell targeted liposomes can be obtained by attaching some antigen-directed monoclonal antibodies (Moab or Moab fragments) or small proteins and molecules (folate, epidermal growth factor, transferrin) to the distal end of polyethylene glycol in pegylated liposomal doxorubicin. The most promising therapeutic application of liposomes is as non-viral vector agents in gene therapy, characterized by the use of cationic phospholipids complexed with the negatively charged DNA plasmid. The use of liposome formulations in local-regional anticancer therapy is also discussed. Finally, pegylated liposomal doxorubicin containing radionuclides are used in clinical trials as tumor-imaging agents or in positron emission tomography.

Liposomal doxorubicin: Doxil®

Objective: Many cytotoxic chemotherapy agents have a narrow therapeutic index. In fact, in some patients, the onset of serious adverse effects may precede any therapeutic benefit. The use of lipo somes to target drug delivery to the site of action can improve a drug's therapeutic index by increasing its efficacy while minimizing toxicity. Liposomal doxo rubicin (Doxil®, Sequus Pharmaceuticals, Inc.)* is the first liposomal chemotherapy product to be approved in the United States. The purpose of this review is to provide a basic understanding of liposomal drug delivery, describe the unique pharmacokinetic prop erties of liposomal doxorubicin (Doxil®), and, finally, comment on this novel drug's place in therapy. Data Sources: Manual and on-line (Medline) literature searches were performed. Search terms included were the brand and generic names of the product, Kaposi's sarcoma, and liposomes. The med ical information department of Sequus Pharmaceuti cals was contacted.

Study Selection: If available, controlled clinical trials with scientific merit were reviewed. Nonran domized studies, case reports, review articles, and letters to editors were considered if appropriate.

Conclusions: Liposomal chemotherapy is one of many attempts to improve cytotoxic chemotherapy by maximizing tumor cell kill while minimizing pa tient adverse effects. Liposomal doxorubicin (Doxil®) is the first of such products approved for use in the United States and has a unique formulation and advantageous pharmacokinetic profile. Liposomal doxorubicin (Doxil®) is both a safe and effective agent in the treatment of advanced AIDS-related Ka posi's sarcoma. The efficacy of liposomal doxorubicin (Doxil®) in the treatment of refractory solid tumors such as breast cancer, lung cancer, colorectal cancer, renal cell cancer, ovarian cancer, and sarcoma has not been demonstrated uniformly. Limited data are avail able regarding the cardiotoxicity potential of this agent; currently no definitive conclusions can be made. Further investigation will be needed to find the ideal dose, dose schedule, and monitoring parameters for the use of liposomal doxorubicin (Doxil®) in patients with solid tumors.

Overview, prevention and management of chemotherapy extravasation

Chemotherapy extravasation remains an accidental complication of chemotherapy administration and may result in serious damage to patients. We review in this article the clinical aspects of chemotherapy extravasation and latest advances in definitions, classification, prevention, management and guidelines. We review the grading of extravasation and tissue damage according to various chemotherapeutic drugs and present an update on treatment and new antidotes including dexrazoxane for anthracyclines extravasation. We highlight the importance of education and training of the oncology team for prevention and prompt pharmacological and non-pharmacological management and stress the availability of new antidotes like dexrazoxane wherever anthracyclines are being infused.

Preparation, pharmacokinetics, biodistribution, antitumor efficacy and safety of Lx2-32c-containing liposome

Lx2-32c is a novel taxane that has been demonstrated to have robust antitumor activity against different types of tumors including several paclitaxel-resistant neoplasms. Since the delivery vehicles for taxane, which include cremophor EL, are all associated with severe toxic effects, liposome-based Lx2-32c has been developed. In the present study, the pharmacokinetics, biodistribution, antitumor efficacy and safety characteristics of liposome-based Lx2-32c were explored and compared with those of cremophor-based Lx2-32c. The results showed that liposome-based Lx2-32c displayed similar antitumor effects to cremophor-based Lx2-32c, but with significantly lower bone marrow toxicity and cardiotoxicity, especially with regard to the low ratio of hypersensitivity reaction. In comparing these two delivery modalities, targeting was superior using the Lx2-32c liposome formulation; it achieved significantly higher uptake in tumor than in bone marrow and heart. Our data thus suggested that the Lx2-32c liposome was a novel alternative formulation with comparable antitumor efficacy and a superior safety profiles to cremophor-based Lx2-32c, which might be related to the improved pharmacokinetic and biodistribution characteristics. In conclusion, the Lx2-32c liposome could be a promising alternative formulation for further development.

Extravasation injuries: a review

Extravasation injuries are common emergencies in clinical practice. If they are not recognized and treated promptly, they can lead to deleterious functional and cosmetic outcomes. There is a vast range of agents involved in these injuries and marked paucity of evidence to support their specific management. Following an extensive literature review, we outline management principles for clinicians involved in the care of patients with extravasation injuries. Key parameters in deciding appropriate management plans include the volume/toxicity of the agent, the necrosis interval of the injury, patient-related factors, as well as the facilities and expertise available in the setting of individual cases of extravasation.

Comparison of pharmacokinetics, tissue distribution and pharmacodynamics of liposomal and free doxorubicin in tumour-bearing mice following intratumoral injection

OBJECTIVES

The clinical application of doxorubicin (DOX) is limited by severe systemic side effects. The aim of this study was to develop a strategy that combined the liposomal DOX (LipDOX) and intratumoral injection to reduce the toxicity and enhance the antitumor efficiency.

METHODS

The pharmacokinetics, tissue distribution and pharmacodynamics of LipDOX compared with free DOX were investigated by intratumoral injection in murine H22 hepatoma-bearing mice at a dose of 20 mg/kg body weight. A sensitive HPLC-tandem mass spectrometry method was used to determine the DOX levels in plasma and tissues. The tumour volume and body weight of mice were measured every 3 days.

KEY FINDINGS

LipDOX administration resulted in 1.3-fold longer mean residence time (MRT) and 2.4-fold higher area under concentration (AUC)-time curve compared with free DOX administration in tumour. Free DOX caused higher peak plasma concentration (Cmax ) than LipDOX in plasma and major organs, which may result in significant mortality for acute cardiac toxicity. After successive 21 days treatment, the final volume of tumour treated by normal saline, free DOX and LipDOX was 5.0-, 1.3-fold higher and 1.6-fold lower than the initial tumour volume, respectively.

CONCLUSIONS

Our results indicated that the intratumoral injection of LipDOX is a promising approach with higher therapeutic efficacy and lower systemic toxicity than free DOX.

Recovery of symptomatic extravasation of liposomal doxorubicin after dexrazoxane treatment

A patient with metastatic ovarian cancer was treated with liposomal doxorubicin and carboplatin. She had an extravasation during liposomal doxorubicin infusion. Initially, she was treated conservatively with cold compresses and topical treatment. However, because of worsening of symptoms, she received dexrazoxane once daily for 3 days after which complete recovery occurred. This is the first casereport on symptomatic extravasation of liposomal doxorubicin treated with dexrazoxane.

[Update in the management of extravasations of cytocytostatic agent]

OBJECTIVE

To present current developments in the specific management of extravasations of antineoplastic agents after the extravasation.

METHOD

We conducted a search in PubMed, Medline and IDIS-Iowa to identify papers written in English or Spanish that described new specific measures for the management of extravasations. We also reviewed the references given in these papers and recent tertiary sources related to oncology or cytostatic agents. The search covered the period between 1997 and 2010.

RESULTS

There are only specific measures for the treatment of extravasations of 22 cytostatic agents. These measures are presented for each cytostatic agent, according their drug group.

CONCLUSIONS

Although currently there is no general consensus on the specific management of antineoplastic agents after extravasation, this review outlines the information collected and published so far, so that it may be of use to any national health centre where cytostatic drugs are prescribed, handled or administered.

Extravasation management: clinical update

OBJECTIVE

To present a clinical update on the prevention, detection, and evidence-based management of vesicant chemotherapy extravasations.

DATA SOURCES

Journal articles, published and unpublished case reports, personal experience.

CONCLUSION

In the 4 years that have elapsed since the publication of the original article, much more is known about vesicant chemotherapy extravasation, and effective evidence-based treatments now are available. The antidotes sodium thiosulfate for mechlorethamine extravasations and hyaluronidase for plant alkaloid extravasations are recommended by the manufacturers of these vesicants and cited in nursing guidelines. The anthracycline extravasation treatment dexrazoxane for injection, the first and only extravasation treatment with proven effectiveness, is now available as Totect (dexrazoxane; TopoTarget USA, Rockaway, NJ, USA) in the US and Savene (SpePharm, Amsterdam, The Netherlands) in Europe.

IMPLICATIONS FOR NURSING PRACTICE

Nurses who administer vesicant chemotherapy agents need to be aware of the most current evidence (or lack of evidence) for various types of extravasation treatment. Well-informed nurses are patient advocates and instrumental in detecting, managing, and documenting extravasations. Most importantly, nurses play a key role in preventing vesicant chemotherapy extravasations.

Anthracycline extravasation injuries: management with dexrazoxane

The application of anthracyclines in anticancer therapy may result in accidental extravasation injury and can be a serious complication of their use. Tissue necrosis with skin ulceration is a possible outcome in the inadvertent extravasation of anthracyclines during intravenous administration. Until recently, there has been no effective treatment against the devastating effect of extravasated anthracycline. Preclinical and clinical studies are leading to the clinical implementation of dexrazoxane as the first and only proven antidote in anthracycline extravasation. In two multicenter studies dexrazoxane has proven to be highly effective in preventing skin necrosis and ulceration. This review focuses on the development and management of dexrazoxane in anthracycline extravasation injuries.

Current recommendations for prevention and therapy of extravasation reactions in dermato-oncology

Despite the introduction of many targeted therapies, a wide variety of cytostatic agents are still frequently used in dermato-oncology. In order to avoid further morbidity in tumor patients, prevention of extravasation reactions is of highest importance. The optimal management of extravasation requires an early diagnosis, the application of specific antidotes and a well-trained oncology team.

Management of anthracycline extravasation injuries

OBJECTIVE

To review the evidence for the management of anthracycline extravasation and determine the optimal treatment of such injuries.

DATA SOURCES

A search of MEDLINE (1966-February 2007) and International Pharmaceutical Abstracts (1970-February 2007) was performed using the search terms anthracyclines and extravasation.

DATA SYNTHESIS

Extravasation of anthracyclines can have devastating effects. After infiltration of these drugs into the interstitial tissue, damage may range from mild erythema and pain to severe tissue necrosis. Many agents have been studied in the management of these injuries; however, few have demonstrated efficacy and treatment remains controversial. Nonpharmacologic modalities shown to limit extravasation injuries include local tissue cooling and elevation of the affected area. Corticosteroids, sodium bicarbonate, hyaluronidase, hyperbaric oxygen, heparin fractions, alpha-tocopherol, N-acetylcysteine, and granulocyte macrophage-colony stimulating factor have all either been shown to be ineffective or have limited data supporting their use. Topical dimethyl sulfoxide (DMSO) has been shown in prospective studies to limit the course of extravasation injuries. Dexrazoxane has been shown in animal models and case reports to be useful in the management of anthracycline extravasation. Two recent prospective clinical trials examining intravenous dexrazoxane 1000 mg/m2 within 6 hours of extravasation, 1000 mg/m2 24 hours after extravasation, and 500 mg/m2 48 hours after extravasation injuries add to the data supporting the use of this agent in such injuries. Of the 54 patients enrolled, surgery-requiring necrosis was avoided in 98.2%.

CONCLUSIONS

The optimal treatment of anthracycline extravasation includes local tissue cooling, elevation of the afflicted extremity, dexrazoxane administration, and possibly topical DMSO. Many other drugs have been investigated; however, due to a lack of data, they cannot be recommended for the management of anthracycline extravasation.

Pegylated liposomal doxorubicin in the treatment of cancers of the breast and ovary

Peglyated liposomal doxorubicin was developed to maintain or enhance the demonstrated antineoplastic effects of doxorubicin, while improving the toxicity profile associated with this important cytotoxic agent. Accumulating clinical data have confirmed the activity of pegylated liposomal doxorubicin in cancers of the breast and ovary. Furthermore, Phase II and III trial experience has revealed that the drug produces objective responses comparable in rate and duration to doxorubicin and other single agents employed in metastatic breast cancer. In recurrent and platinum-resistant ovarian cancer, single-agent pegylated liposomal doxorubicin has assumed an important role in routine patient management.

Skin toxicity associated with pegylated liposomal doxorubicin (40 mg/m2) in the treatment of gynecologic cancers

OBJECTIVES

To characterize the incidence of skin toxicity of pegylated liposomal doxorubicin (PLD) administered at a lower dose (40 mg/m(2)) in the treatment of advanced gynecologic malignancies.

METHODS

Medical charts of all patients who initiated PLD at a starting dose of 40 mg/m(2) from 1997 to 2003 for the treatment of gynecologic cancers were retrospectively reviewed. PLD was infused over 1-2 h and administered every 4-6 weeks. No patient had previously received doxorubicin. All patients were clinically assessed for adverse reactions including skin toxicity.

RESULTS

Ninety patients (mean age 62 years, range 45-82 years) were included in this analysis. There were 55 ovarian, 16 endometrial, 2 fallopian, and 17 primary peritoneal cancers. The median cumulative dose of PLD was 120 mg/m(2) (range 40-855 mg/m(2)) with a median of 3 cycles (range 1-25). 33/90 (37%) developed a skin reaction during therapy. The overall incidence of grade 1, 2, and 3 skin toxicity was 23 (26%), 9 (10%), and 1 (1%), respectively. Of the 23 cases of grade 1 toxicity, 16 (70%) occurred within 1-3 cycles. All 9 cases of grade 2 toxicity occurred within 1-3 cycles. The only case of grade 3 toxicity occurred after the first cycle. 28/30 (93%) patients who continued treatment did not experience further episodes of skin toxicity with subsequent cycles after a dose reduction (5-20 mg/m(2)). PLD was stopped in only 2/90 (2%) cases due to a skin reaction.

CONCLUSIONS

Severe skin toxicity (> or =grade 2) associated with PLD occurs infrequently when initial doses of 40 mg/m(2) are administered. When skin reactions appear, they usually occur early in the course of treatment, respond to dose reduction, and do not appear to limit the duration of treatment.

Paclitaxel and pegylated-liposomal doxorubicin are both active in angiosarcoma

BACKGROUND

Paclitaxel has unique activity in angiosarcomas of the face and scalp, but its activity in angiosarcomas originating at other sites is less well defined. Paclitaxel and pegylated-liposomal doxorubicin (PLD) are highly effective in Kaposi sarcoma (KS). Because of the efficacy of PLD in soft tissue sarcoma in general, and in KS in particular, coupled with potential similarities in KS and angiosarcoma, and the apparent activity of paclitaxel in angiosarcomas, the authors treated patients with angiosarcoma with either paclitaxel or PLD as initial chemotherapy.

METHODS

To better define the efficacy of these agents in angiosarcoma, the authors reviewed their experience with paclitaxel and PLD in patients with angiosarcoma treated between 1994 and 2004.

RESULTS

They identified seven patients with angiosarcoma treated with paclitaxel, and six treated with PLD. Only one patient in the series had an angiosarcoma of the scalp. Two patients receiving paclitaxel had received previous therapy with PLD, and four of six patients treated with PLD had previously received paclitaxel. Of the eight patients treated with paclitaxel, five had major responses (three had partial responses [PR] and two had complete disease remission [CR]) and three had progressive disease (PD). Of the 6 patients who received PLD, 3 had a PR for 6, 19, and >20 months, respectively, 2 had stable disease for 7 and 11 months, respectively, and 1 had PD.

CONCLUSIONS

The current study demonstrated the activity of PLD (five of six patients experienced clinical benefit) and extended the data on paclitaxel in angiosarcoma, both of the face and scalp, as well as angiosarcoma originating at other sites.

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.

Liposomal anthracycline administration and toxicity management: A nursing perspective

Nursing care of the patient receiving chemotherapy includes patient education and drug administration, as well as ongoing assessment, early identification, and intervention for side effects. Two liposomal anthracyclines are available in the United States, pegylated liposomal doxorubicin (Doxil/Caelyx [PLD]) and liposomal daunorubicin (DaunoXome [DNX]). Because of their unique liposomal formulations, the administration and toxicity profiles of these agents are different from those of conventional anthracyclines, as well as each other. Common severe toxicities of conventional anthracycline treatment such as nausea/vomiting, alopecia, and neutropenia are less frequent and less severe during liposomal anthracycline treatment, and cumulative-dose cardiotoxicity is rare, particularly with PLD therapy. Dose-related adverse events with liposomal anthracycline therapy include stomatitis and neutropenia, and more frequent doses of PLD are associated with hand-foot syndrome. Ongoing nursing assessment, patient education, and adjustments to the dose or dose-schedule can reduce the severity or frequency of these toxicities. Nurses must be aware of the unique characteristics of liposomal anthracycline therapy to provide optimal patient education and nursing care.

Multicenter study of pegylated liposomal doxorubicin in patients with cutaneous T-cell lymphoma

BACKGROUND

In single center studies and case reports, it was shown that pegylated liposomal doxorubicin (PEG-DOXO) was effective as second-line therapy for patients with cutaneous T-cell lymphoma (CTCL). The objective of this study was to evaluate the efficacy and toxicity of single-agent PEG-DOXO as second-line chemotherapy in patients with CTCL.

METHODS

A retrospective, multicenter study was performed evaluating 34 patients (31 male patients and 3 female patients). Twenty-seven patients received PEG-DOXO 20 mg/m(2), 5 patients received PEG-DOXO 20-30 mg/m(2), and 2 patients received PEG-DOXO 40 mg/m(2). PEG-DOXO was administered intravenously every 2 weeks in 6 patients, every 2-3 weeks in 4 patients, and every 4 weeks in 23 patients. One patient received only a single course of PEG-DOXO. Outcomes were evaluated, and adverse effects were recorded.

RESULTS

Thirty-four patients received at least 1 cycle of PEG-DOXO. Disease was classified as mycosis fungoides in 28 patients, mycosis fungoides with follicular mucinosis in 2 patients, small or medium-sized pleomorphic CTCL in 2 patients, Sèzary syndrome in 1 patient, and CD30 positive CTCL in 1 patient. Fifteen patients achieved a complete response (CR), including patients who achieved a CR and patients who achieved a CR defined by clinical criteria only with no biopsy (CRu), and 15 patients achieved a partial response (PR), resulting in a response rate (CRs, CRus, and PRs) of 88.2%. Two patients dropped out: one patient after a single PEG-DOXO infusion because of Grade 3 capillary leakage syndrome and one patient after two cycles because of a suicide attempt that was not related to treatment or to CTCL. All other patients received at least four cycles of PEG-DOXO. Overall survival was 17.8 months +/- 10.5 months (n = 33 patients), event-free survival was 12.0 months +/- 9.5 months, and disease-free survival was 13.3 +/- 10.5 months (n = 16 patients). Adverse effects were seen in 14 of 34 patients (41.2%); they were temporary and generally mild. Only 6 patients had Grade 3 or 4 adverse effects.

CONCLUSIONS

This multicenter study provided evidence of high efficacy of PEG-DOXO monotherapy with a low rate of severe adverse effects compared with other chemotherapy protocols in patients with CTCL.

Phase II trial of pegylated-liposomal doxorubicin (Doxil) in sarcoma

Pegylated-liposomal doxorubicin (Doxil) is a unique form of liposomal doxorubicin in which the liposomes are coated with methoxypoly (ethylene glycol), resulting in a diminished uptake by the reticuloendothelial system, leading to a longer half-life in blood and a different toxicity profile than nonpegylated liposomes. We performed a phase II study of Doxil in sarcoma. The patient population was primarily previously treated or had diagnoses considered unresponsive to chemotherapy. The initial dose per course was 55 mg/m2 every four weeks with dose modification based on mucositis and hand-foot syndrome (the main limiting toxicities). Treatment was generally well tolerated. Of 214 evaluable treatment courses in 47 patients, toxicities were mild and similar to previous reports, but dose reduction was common. No definite cardiac toxicity was observed. There were: 6 osteosarcomas, 3 Ewings, 1 extraosseous osteosarcoma, 1 chondrosarcoma, 2 alveolar soft part sarcomas, 15 gastrointestinal stromal cell tumors (GIST), and 19 other soft tissue sarcomas. Three of the 47 patients received a CR or PR, although 15 of the 47 patients were felt to have derived clinical benefit from the treatment. Some responses were delayed. These data suggest that pegylated-liposomal doxorubicin has activity in this population of poor prognosis sarcoma and that this treatment is associated with modest toxicity.

Liposomally targeted cytotoxic drugs for the treatment of cancer

Phospholipid spherules composed of lipid bilayer membranes entrapping a central aqueous core were first described more than 30 years ago (Bangham et al 1965). The term liposome was coined in 1968 (Sessa & Weissmann 1968) and the first suggestions that these vesicles might have potential as vehicles for targeted drug delivery for a range of diseases, including cancer, appeared shortly afterwards (Gregoriades et al 1974; Gregoriades 1976a, b). However, the process of turning this expectation into a clinical reality has suffered a number of setbacks and has taken more than a quarter of a century. In the process, new types of liposomes with favourable in-vivo pharmacokinetics and biodistribution patterns have been generated (Lasic & Papahadjopoulos 1995). Many of these preparations have been subjected to extensive examination and an increasing number of agents have entered clinical trials. In this review, we will trace the development of those liposomes that are currently undergoing (or are about to undergo) clinical evaluation.

Totally implantable venous-access ports: local problems and extravasation injury

Totally implantable venous-access ports (TIVAPs) are valuable instruments for long-term intravenous treatment of patients with cancer, but implantation and use of these devices are each associated with complications. In addition to the perioperative problems, long-term complications can arise; these can be classified in five categories-catheter malfunction, catheter-related venous thrombosis, catheter-related infection, port-related complications, and extravasation injury. Such complications reduce the benefits of reliable access to the venous system in patients with malignant tumours. The vast majority of such disadvantages are attributable to inexpert handling of ports and, therefore, should be avoidable. TIVAP placement procedures and TIVAP complications are discussed in this review, with special emphasis on local problems and extravasation injuries. To obtain maximum benefit from TIVAPs, all health-care personnel must be familiar with the use and routine maintenance procedures of the devices and treatment options for catheter-related complications.

A novel approach for the increased delivery of pharmaceutical agents to peritoneum and associated lymph nodes

A novel method for prolonging the retention of liposomes in the peritoneum while increasing liposome deposition in lymph nodes that drain the peritoneum is described. An aliquot (1 ml) of technetium-99m ((99m)Tc)-biotin-liposomes encapsulating blue dye was injected intraperitoneally in rats. Thirty minutes after administration of the (99m)Tc-blue-biotin-liposomes, five rats (experimental) were administered avidin (5 mg) intraperitoneally, whereas the remaining five rats served as controls. Scintigraphic images were acquired at baseline and 1 and 24 h after the liposome injection followed by a tissue biodistribution study. Images at 24 h clearly demonstrated very different distributions between the experimental and control animals. In experimental rats, most of the activity was visualized in the abdominal region, and in abdominal and mediastinal lymph nodes. The percentage of the injected dose (% ID) in the blood was significantly higher in the control group than in the experimental group (14.0 +/- 1.7 versus 0.17 +/- 0.03%; P < 0.001). The % ID in the spleen was also significantly greater for controls (23.3 +/- 3.9%) compared with the experimental group (0.78 +/- 0.8%; P = 0.001). Significant (99m)Tc activity was detected in blue-stained abdominal nodes (4.7%) and mediastinal nodes (2.3%) from the experimental animals, whereas no blue-stained nodes were detectable in the control animals. The intraperitoneal biotin-liposome/avidin delivery system described in this study could potentially be used for delivery of liposome-encapsulated drugs to disease processes that become disseminated in the peritoneum such as metastatic ovarian, gastric, and colorectal cancer, as well as infectious peritonitis.

Phase II trial of pegylated-liposomal doxorubicin (Doxil) in mesothelioma

Pegylated-liposomal doxorubicin (Doxil) is a form of liposomal doxorubicin in which the liposomes are coated with methoxypoly(ethylene glycol), resulting in a diminished uptake by the reticuloendothelial system, a longer half-life in blood, and a different toxicity profile than nonpegylated liposomes. A phase II study of Doxil in mesothelioma was performed. The initial dose per course was 55 mg/m2 every 4 weeks with dose modification based on mucositis and hand-foot syndrome (the main limiting toxicities). Treatment was generally well tolerated. Of 73 evaluable treatment courses in 15 patients, toxicities were mild and similar to previous reports, but dose reduction was common. No definite cardiac toxicity was observed. Fourteen patients were evaluable for response; four of the 15 patients treated responded meaningfully. These data suggest that pegylated-liposomal doxorubicin has activity in mesothelioma, and that this treatment is associated with modest toxicity.

Dapsone for the treatment of doxorubicin extravasation injury in the rat

Doxorubicin is the most common antitumor drug implicated in serious extravasation injuries. Progressive tissue necrosis may lead to intense pain, chronic ulceration, and disfiguring tissue loss. This progressive necrosis is analogous to that seen with brown recluse spider bites, where dapsone is an established mode of therapy, minimizing the area of tissue loss by a proposed antiinflammatory mechanism. The backs of 50 Lewis rats were injected intradermally with 1 mg of doxorubicin in 1 cc of saline to simulate an extravasation injury. The rats were divided into five groups for treatment with oral dapsone 50 mg/kg/day: 10 were controls (no treatment), 10 were started the day before injury, 10 were started the day of injury, 10 were started the day after injury, and 10 were started 1 week after injury. The area of ulceration was calculated by planimetry. The data suggest that dapsone has little positive effect on healing extravasation ulcers.

Pegylated liposomal doxorubicin: metamorphosis of an old drug into a new form of chemotherapy

Pegylated liposomal doxorubicin (Doxil, Caelyx) is a formulation of doxorubicin in poly(ethylene glycol)-coated (stealth) liposomes with a prolonged circulation time and unique toxicity profile. We review the preclinical and clinical pharmacology as well as recent clinical data obtained in specific cancer types. Doxil liposomes retain the drug payload during circulation and accumulate preferentially in tissues with increased microvascular permeability, as often is the case of tumors. Doxil toxicity profile is drastically different from that of doxorubicin, and is characterized by dominant and dose-limiting mucocutaneous toxicities, mild myelosuppression, minimal alopecia, and no apparent cardiac toxicity. Although the single maximum tolerated dose (MTD) of Doxil is actually lower than that of conventionally administered doxorubicin, the cumulative MTD dose of Doxil may be substantially greater than that of free doxorubicin. Doxil is probably one of the most active agents in AIDS-related Kaposi's sarcoma and has a definite role in management of recurrent ovarian cancer. The potential of Doxil in the treatment of other cancer types and the opportunities it offers in combination with other drugs and therapeutic modalities are under active investigation.

Intra-tumoral injection of doxorubicin (adriamycin) encapsulated in liposome inhibits tumor growth, prolongs survival time and is not associated with local or systemic side effects

Encapsulation of doxorubicin (Adriamycin) in liposome (LipADM) augments the anti-tumor effects of the drug and reduces side effects such as cardiotoxicity. However, it does not always enhance anti-tumor effects because of entrapment by the reticuloendothelial system. In this study, we investigated the anti-tumor effect of LipADM injected directly into the tumor to augment tumor targeting. LipADM (7.5 mg/kg body weight), the same concentration as free ADM (FADM), was injected percutaneously or i.v. into 7-day-old established Meth-A tumors in mice. Mock liposome was injected percutaneously into tumors of control mice. Mean relative tumor weights of the 5 groups on day 15 were as follows: intra-tumoral injection of LipADM, 2.92 +/- 1.09; intra-tumoral injection of FADM, 6.99 +/- 2.92; i.v. injection of LipADM, 11.07 +/- 7.95; i.v. injection of FADM, 11.80 +/- 6.55; control, 23.94 +/- 9.03. Mean survival times were as follows: intra-tumoral injection of LipADM, 46.2 +/- 11.0 days; FADM, 34.6 +/- 9.6 days; mock control, 30.2 +/- 4.8 days. Histological examination showed no tissue damage at the site of s.c. injection of LipADM. ADM concentrations in tumor tissues after intra-tumoral injection were persistently high in the LipADM-treated group. Our results indicate that direct injection of LipADM into the tumor is therapeutically useful by producing persistently high concentrations of ADM in the target tissue, with few local and systemic side effects.

Phase 2 trial of liposomal doxorubicin (40 mg/m(2)) in platinum/paclitaxel-refractory ovarian and fallopian tube cancers and primary carcinoma of the peritoneum

BACKGROUND

Several studies have demonstrated liposomal doxorubicin (Doxil) to be an active antineoplastic agent in platinum-resistant ovarian cancer, with dose limiting toxicity of the standard dosing regimen (50 mg/m(2) q 4 weeks) being severe erythrodysesthesia ("hand-foot syndrome") and stomatitis. We wished to develop a more tolerable liposomal doxorubicin treatment regimen and document its level of activity in a well-defined patient population with platinum/paclitaxel-refractory disease.

METHODS AND MATERIALS

Patients with ovarian or fallopian tube cancers or primary peritoneal carcinoma with platinum/paclitaxel-refractory disease (stable or progressive disease following treatment with these agents or previous objective response <3 months in duration) were treated with liposomal doxorubicin at a dose of 40 mg/m(2) q 4 weeks.

RESULTS

A total of 49 patients (median age: 60; range 41-81) entered this phase 2 trial. The median number of prior regimens was 2 (range: 1-6). Six (12%) and 4 (8%) patients experienced grade 2 hand-foot syndrome and stomatitis, respectively (no episodes of grade 3). One patient developed grade 3 diarrhea requiring hospitalization for hydration. Six (12%) individuals required dose reductions. The median number of courses of liposomal doxorubicin administered on this protocol was 2 (range: 1-12). Four of 44 patients (9%) evaluable for response exhibited objective and subjective evidence of an antineoplastic effect of therapy.

CONCLUSION

This modified liposomal doxorubicin regimen results in less toxicity (stomatitis, hand-foot syndrome) than the standard FDA-approved dose schedule. Definite, although limited, antineoplastic activity is observed in patients with well-defined platinum- and paclitaxel-refractory ovarian cancer.

Biodistribution and pharmacokinetics of 111In-DTPA-labelled pegylated liposomes in a human tumour xenograft model: implications for novel targeting strategies

The biodistribution and pharmacokinetics of 111In-DTPA-labelled pegylated liposomes in tumour-bearing nude mice was studied to examine possible applications of pegylated liposome-targeted anti-cancer therapies. Nude mice received an intravenous injection of 100 microl of 111In-DTPA-labelled pegylated liposomes, containing 0.37-0.74 MBq of activity. The t1/2alpha and t1/2beta of 111In-DTPA-labelled pegylated liposomes were 1.1 and 10.3 h, respectively. Tumour uptake was maximal at 24 h at 5.5 +/- 3.0% ID g(-1). Significant reticuloendothelial system uptake was demonstrated with 19.3 +/- 2.8 and 18.8 +/- 4.2% ID g(-1) at 24 h in the liver and spleen, respectively. Other sites of appreciable deposition were the kidney, skin, female reproductive tract and to a lesser extent the gastrointestinal tract. There was no indication of cumulative deposition of pegylated liposomes in the lung, central nervous system, musculoskeletal system, heart or adrenal glands. In contrast, the t1/2alpha and t1/2beta of unencapsulated 111In-DTPA were 5 min and 1.1 h, respectively, with no evidence of accumulation in tumour or normal tissues. Incubation of 111In-DTPA-labelled pegylated liposomes in human serum for up to 10 days confirmed that they are very stable, with only minor leakage of their contents. The potential applications of pegylated liposomes in the arena of targeted therapy of solid cancers are discussed.

Pegylated liposomal adriamycin: a review of current and future applications

Anthracyclines such as adriamycin have a broad spectrum of activity in human tumours, but are limited, to an extent, by their non-selective delivery to a host of normal tissues and hence, subsequent toxicity. The development of liposomes has offered a drug delivery system with significant potential to target tumours whilst sparing normal tissues. A significant breakthrough has been achieved by coating the liposome with polyethylene glycol (pegylation), and thus altering the pharmacokinetics of the drug considerably. In this review, the authors discuss the promising data now emerging with pegylated liposomal adriamycin, and also describe possible future applications.

Acquired immunodeficiency syndrome-associated Kaposi's sarcoma. Biology and management

Kaposi's Sarcoma (KS), the most common AIDS-associated malignancy, occurs with increased frequency in all HIV transmission groups, but at a particularly high rate in homosexual men. Recent studies suggest that KS pathogenesis involves exposure to an infectious agent, altered expression and response to cytokines, and modulation of growth by HIV gene products. KS varies in its clinical presentation from a relatively indolent process to a widely disseminated, aggressive disease. A variety of local and systemic treatments provide effective, but usually temporary, disease palliation. Insights into KS pathogenesis suggest a number of targeted therapeutic approaches that may eventually lead to improved disease management and disease cure.

Chemotherapy of AIDS--related Kaposi's sarcoma

Kaposi's sarcoma (KS) is the most common tumor associated with AIDS. A growing number of patients with this tumor are presenting at later stages of HIV with more rapidly progressive, extensive, or symptomatic KS or with tumors involving visceral organs. Chemotherapy treatment is effective in inducing tumor regression, reducing edema, and ameliorating symptoms caused by these tumors. Side effects and toxicities from these agents, however, can be quite pronounced, especially in patients with advanced AIDS Antiretroviral therapy, prophylaxis for opportunistic infections, and the use of hematopoietic growth factors should be routinely included in the management of these patients. Newer chemotherapeutic agents and combination regimens may be more effective or less toxic than previously evaluated regimens.