WR-2721 and high-dose cisplatin: an active combination in the treatment of metastatic melanoma

Chimeric antigen receptor T-cell therapy for melanoma

INTRODUCTION

In recent years, chimeric antigen receptor (CAR) T cell therapy has emerged as a cancer treatment. After initial therapeutic success for hematologic malignancies, this approach has been extended for the treatment of solid tumors including melanoma.

AREAS COVERED

T cells need to be reprogramed to recognize specific antigens expressed only in tumor cells, a difficult problem since cancer cells are simply transformed normal cells. Tumor antigens, namely, CSPG4, CD70, and GD2 have been targeted by CAR-T cells for melanoma. Moreover, different co-stimulatory signaling domains need to be selected to direct T cell fate. In this review, various approaches for the treatment of melanoma and their effectiveness are comprehensively reviewed and the current status, challenges, and future perspective of CAR-T cell therapy for melanoma are discussed. Literature search was accomplished in three databases (PubMed, Google scholar, and Clinicaltrials.gov). Published papers and clinical trials were screened and relevant documents were included by checking pre-defined eligibility criteria.

EXPERT OPINION

Despite obstacles and the risk of adverse events, CAR T cell therapy could be used for patients with treatment-resistant cancer. Clinical trials are underway to determine the efficacy of this approach for the treatment of melanoma.

Melanoma: Where we are and where we go

Melanoma is known as an aggressive tumor which shows an increasing incidence and poor prognosis in the metastatic phase. Hence, it seems that diagnosis and effective management (including early diagnosis, choosing of the effective therapeutic platform, caring, and training of patients for early detection) are major aspects of melanoma therapy. Early detection of melanoma is a key point for melanoma therapy. There are various diagnosis options such as assessing of biopsy, imaging techniques, and biomarkers (i.e., several proteins, polymorphism, and liquid biopsy). Among the various biomarkers, assessing circulating tumor cells, cell-free DNAs, cell-free RNAs, and microRNAs (miRNAs) have emerged as powerful diagnosis tools for melanoma patients. Deregulations of these molecules are associated with melanoma pathogenesis. After detection of melanoma, choosing of effective therapeutic regimen is a key step for recovery of melanoma patients. Several studies indicated that various therapeutic approaches including surgery, immunotherapy, systematic therapy, radiation therapy and antibodies therapy could be used as potential therapeutic candidates for melanoma therapy. Caring for melanoma patients is one of the important components of melanoma therapy. Caring and training for melanoma patients could contribute to better monitoring of patients in response to various therapeutic options. Here, we summarized various diagnosis approaches such as assessing biopsy, imaging techniques, and utilization of various biomarkers (i.e., proteins, CTCs, cfDNAs, and miRNAs) as a diagnostic biomarker for detection and monitoring patients with melanoma. Moreover, we highlighted various therapeutic options and caring aspects in patients with melanoma.

Combined Carboplatin and Cytosine Arabinoside in Metastatic Melanoma Refractory to Dacarbazine

This is a preliminary report on the efficacy and toxicity of the combination chemotherapy regimen with carboplatin and cytosine arabinoside in dacarbazine-resistant metastatic melanoma. Patients were considered eligible in the presence of measurable disease sites, an ECOG performance status of 2 or less, a life expectancy of at least 2 months, and prior dacarbazine treatment. The planned schedule consisted of cytosine arabinoside (150 mg/m2 intravenously plus 50 mg subcutaneously), followed by a rapid infusion of carboplatin (350 mg/m2 on day 1). Courses were administred every 3 weeks according to hematologic recovery. Twenty-one consecutive patients were evaluable for activity and toxicity, the response rate was 19% (95% confidence interval, 5-42%). There was no complete remission. Toxicity was tolerable being myelosuppression the main side effect. In conclusion, the combination of carboplatin and cytosine arabinoside has limited activity as a salvage treatment in melanoma patients failing on dacarbazine chemotherapy. Moreover, the regimen is well tolerated and easy to administer in an outpatient setting.

Preliminary Experience with High-Dose Cisplatin, Reduced Glutathione and Natural Interferon-α in Dacarbazine-Resistant Malignant Melanoma

Aims and background

The incidence of malignant melanoma is rapidly increasing in many countries, and when this disease has reached advanced stages, standard therapies have little impact. Dacarbazine (DTIC) is the most effective chemotherapeutic agent with an overall response rate of 20-25%, but durable responses are uncommon. Interesting results with the use of cisplatin (CDDP) have been reported in DTIC-resistant melanoma. Moreover, malignant melanoma is an immunogenic tumor and a potential target for biological response modifier (BRM) therapies. The aim of the present study was to evaluate the efficacy and tolerability of a chemo-immunotherapeutic regimen including high-dose CDDP combined with glutathione (GSH) to limit platinum-related toxicity, and natural interferon-α (IFN-α) in patients with DTIC-resistant metastatic melanoma.

Methods

The treatment schedule included GSH 1,500 mg/m2 i.v. and CDDP 40 mg/m2 i.v. for 4 consecutive days every 3 weeks, with a maximum of 6 courses, and IFN-α 3 MIU i.m. 3 times a week, continuative for a maximum of 12 months.

Results

Twelve patients were enrolled in this phase II trial. Accrual was stopped due to treatment-related toxicity. Ten patients were evaluable for response; there were 2 partial responses, lasting 5+ and 9+ months, respectively, and 2 cases of stable disease, lasting 3+ and 8+ months. None of these patients completed the therapeutic program due to treatment-related side effects.

Conclusions

This regimen seems to be only partially active in DTIC-resistant metastatic melanoma. Hematologic and non-hema-tologic (nausea and vomiting, peripheral neurotoxicity, and asthenia) side effects are significant and GSH is not effective in limiting CDDP-related neurotoxicity in pretreated patients. Therefore, there is no indication to employ this regimen as second-line treatment in metastatic melanoma and these disappointing results highlight the urgent need for new therapeutic approaches.

Amifostine does not protect thyroid cancer cells in DNA damaging in vitro models

BACKGROUND

Amifostine is a potent scavenger of reactive oxygen species that is used for the salivary gland protection during therapy with radioactive iodine for thyroid cancer. There are no data on the potential effect of amifostine on thyroid cancer cells.

METHODS

We investigated the effects of the active form of amifostine (WR-1065) on the response of thyroid cancer cells to treatment with DNA-damaging agents. WR-1065 was examined in human thyroid cancer cell lines (FTC133, TPC1, BCPAP and C643) and embryonic fibroblast cells NIH3T3. DNA damage was induced by exposure to H₂O₂ (0.1 mM), by treatment with the radiomimetic neocarzinostatin (NCS 250 ng/mL) and by γ-radiation (6 Gy). DNA damage, cell viability and apoptosis were examined.

RESULTS

We demonstrated the selective action of WR-1065 (0.1 mM), which prevented oxidative stress-induced DNA damage in fibroblasts, but did not protect thyroid cancer cells from DNA damage and apoptosis documented by caspase-3 and PARP cleavage after exposure to H₂O₂, NCS and γ-radiation. Prolonged exposure to WR-1065 (0.1 mM for 24 h) was toxic for thyroid cancer cells; this treatment decreased the number of viable cells by 8% in C643 cells, 47% in TPC cells, 92% in BCPAP cells and 82% in FTC 133 cells. The cytotoxic effects of WR-1065 were not associated with induction of apoptosis.

CONCLUSIONS

Our data show that amifostine has no protective effect on thyroid cancer cells against DNA-damaging agents in vitro and suggest that amifostine will not attenuate the efficacy of radioiodine treatment in patients with thyroid cancer.

The role for chemotherapy in the modern management of melanoma

The treatment of malignant melanoma has changed beyond recognition in the last 7 years. Where previously single agent dacarbazine was often the only treatment used for advanced disease, now there are potentially multiple lines of treatment, based on immunotherapy and targeted treatment options, either as monotherapy or in combination. In this brave new world the question arises, does chemotherapy still have any relevance in the modern management of melanoma? In this review, we summarize the various chemotherapeutic options that have been trialled in melanoma to date, and discuss the role chemotherapy may still play in treating melanoma, potentially in combination with more novel agents, or in certain subtypes of melanoma.

Common Chemical Inductors of Replication Stress: Focus on Cell-Based Studies

DNA replication is a highly demanding process regarding the energy and material supply and must be precisely regulated, involving multiple cellular feedbacks. The slowing down or stalling of DNA synthesis and/or replication forks is referred to as replication stress (RS). Owing to the complexity and requirements of replication, a plethora of factors may interfere and challenge the genome stability, cell survival or affect the whole organism. This review outlines chemical compounds that are known inducers of RS and commonly used in laboratory research. These compounds act on replication by direct interaction with DNA causing DNA crosslinks and bulky lesions (cisplatin), chemical interference with the metabolism of deoxyribonucleotide triphosphates (hydroxyurea), direct inhibition of the activity of replicative DNA polymerases (aphidicolin) and interference with enzymes dealing with topological DNA stress (camptothecin, etoposide). As a variety of mechanisms can induce RS, the responses of mammalian cells also vary. Here, we review the activity and mechanism of action of these compounds based on recent knowledge, accompanied by examples of induced phenotypes, cellular readouts and commonly used doses.

Review : Amifostine and other chemoprotective agents in cancer chemotherapy: A brief review

Objective. Cytotoxic chemotherapy is a frequently, and increasingly, used treatment for malignant disease and is associated with substantial toxicity. A number of drugs have been developed in recent years for the prevention and treatment of chemotherapy-induced toxicity. Most are specific to one group of drugs, eg, mesna and the oxazophosphorines, or one type of toxicity, eg, the 5-HT3 antagonist antiemetics. The first multiorgan cytoprotective, amifostine, recently was launched, and another, glutathione, is under development. The purpose of this review is to con sider the agents currently available for the manage ment of cytotoxic drug-induced toxicity and their place in treatment. Special attention is directed to amifostine and drugs in development, including glu tathione, Ossirene (Baker Norton), ORG-2766, and dexrazoxane and less to agents in routine clinical use.

Data sources. A variety of sources were used, including manual and on-line (Medline) literature searching. Approved and other drug names were used as the primary search terms, linked with cytotoxic chemotherapy where limitation was required. Medi cal information departments of drug companies also were used where appropriate.

Study selection. Particular attention was directed to randomized clinical trials, but nonrandomised and animal studies were considered where appropriate.

Conclusions. Over the past decade significant advances have been made in the control of chemo therapy-induced toxicity and new agents promise even greater control. This is important, not only because they may improve the quality of life of conventionally treated cancer patients, but also be cause they should allow the dose-response relation ship for cytotoxic drug treatment to be fully explored. Unfortunately, the data available at present are insuf ficient to determine the extent to which this promise will be fulfilled.

Evaluation of anti-metastatic potential of Cisplatin polymeric nanocarriers on B16F10 melanoma cells

Nanoparticles are being increasingly used in the field of cancer treatment due to their unique properties and advantages. The aim of the present research work was to prepare and characterize a polymeric albumin nanosystem for Cisplatin and evaluate its in-vitro efficacy against B16F10 melanoma. The developed nanoparticles were almost spherical in shape with a particle size in the range of 150–300 nm, low polydispersity values and about 80% drug entrapment efficiency. Albumin nanocarriers sustained the release of Cisplatin for more than 48 h, suggesting the reduction in dosing schedule for this drug. The results from in-vitro cell line studies indicated the dose dependent cytotoxic potential of drug loaded albumin nanoparticles, their potential to inhibit cell proliferation and induce morphological changes. In addition, these nanoparticles exhibited superiority to Cisplatin in hampering the cell migration. Developed nanoparticles caused cell cycle arrest along with time and concentration dependent cellular uptake in B16F10 cell line. These results signify that the prepared Cisplatin albumin nanoparticles could serve as a promising approach for B16F10 melanoma treatment.

The role of chemotherapy in the modern management of melanoma

The last 4 years have seen dramatic changes in the treatment of advanced melanoma, largely based on advances in targeted therapy and immunotherapy. This article examines the role of chemotherapy in the modern management of melanoma. We examine the evidence for promising new agents and discuss their position in the sequencing of treatment options for patients with advanced disease. In addition, we discuss the combination of chemotherapy with targeted treatments and immune therapies. Finally, we discuss future areas of research for ensuring that we maximize the potential of all agents available to us and identify new, effective treatments.

Latest advances in chemotherapeutic, targeted, and immune approaches in the treatment of metastatic melanoma

Melanoma is the most dangerous form of skin cancer owing to its metastatic potential and is an important public health concern. The melanoma incidence has been increasing worldwide. Although potentially curable when diagnosed early, metastatic melanoma carries a poor prognosis. Until recently, systemic therapy for metastatic melanoma was ineffective, but the recent successes in the development of new therapies for metastatic melanoma, such as mitogen-activated protein kinase (MAPK) pathway inhibitors, anti-cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), and programmed cell death protein 1 (PD-1)/programmed cell death ligand 1 (PD-L1) pathway blocking antibodies, as well as combination strategies of cytotoxic chemotherapy and inhibitors of angiogenesis, have all yielded promising results, changing the continually evolving landscape of therapeutic options for patients with this disease. The aim of this review was to summarize the evolution of and recent advances in the treatment of metastatic melanoma. Therefore, we conducted a comprehensive PubMed search between January 1, 1960, and February 1, 2014, using the search term melanoma or metastatic melanoma combined with terms such as chemotherapy, immunotherapy, CTLA-4, PD-1, PD-L1, adoptive T cell, targeted therapy, MAPK, molecular biology, and survival.

Interventions for preventing neuropathy caused by cisplatin and related compounds

BACKGROUND

Cisplatin and several related antineoplastic drugs used to treat many types of solid tumours are neurotoxic, and most patients completing a full course of cisplatin chemotherapy develop a clinically detectable sensory neuropathy. Effective neuroprotective therapies have been sought.

OBJECTIVES

To examine the efficacy and safety of purported chemoprotective agents to prevent or limit the neurotoxicity of cisplatin and related drugs.

SEARCH METHODS

On 4 March 2013, we searched the Cochrane Neuromuscular Disease Group Specialized Register, CENTRAL, MEDLINE, EMBASE, LILACS, and CINAHL Plus for randomised trials designed to evaluate neuroprotective agents used to prevent or limit neurotoxicity of cisplatin and related drugs among human patients.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) or quasi-RCTs in which the participants received chemotherapy with cisplatin or related compounds, with a potential chemoprotectant (acetylcysteine, amifostine, adrenocorticotrophic hormone (ACTH), BNP7787, calcium and magnesium (Ca/Mg), diethyldithiocarbamate (DDTC), glutathione, Org 2766, oxcarbazepine, or vitamin E) compared to placebo, no treatment, or other treatments. We considered trials in which participants underwent evaluation zero to six months after completing chemotherapy using quantitative sensory testing (the primary outcome) or other measures including nerve conduction studies or neurological impairment rating using validated scales (secondary outcomes).

DATA COLLECTION AND ANALYSIS

Two review authors assessed each study, extracted the data and reached consensus, according to standard Cochrane methodology.

MAIN RESULTS

As of 2013, the review includes 29 studies describing nine possible chemoprotective agents, as well as description of two published meta-analyses. Among these trials, there were sufficient data in some instances to combine the results from different studies, most often using data from secondary non-quantitative measures. Nine of the studies were newly included at this update. Few of the included studies were at a high risk of bias overall, although often there was too little information to make an assessment. At least two review authors performed a formal review of an additional 44 articles but we did not include them in the final review for a variety of reasons.Of seven eligible amifostine trials (743 participants in total), one used quantitative sensory testing (vibration perception threshold) and demonstrated a favourable outcome in terms of amifostine neuroprotection, but the vibration perception threshold result was based on data from only 14 participants receiving amifostine who completed the post-treatment evaluation and should be regarded with caution. Furthermore the change measured was subclinical. None of the three eligible Ca/Mg trials (or four trials if a single retrospective study was included) described our primary outcome measures. The four Ca/Mg trials included a total of 886 participants. Of the seven eligible glutathione trials (387 participants), one used quantitative sensory testing but reported only qualitative analyses. Four eligible Org 2766 trials (311 participants) employed quantitative sensory testing but reported disparate results; meta-analyses of three of these trials using comparable measures showed no significant vibration perception threshold neuroprotection. The remaining trial reported only descriptive analyses. Similarly, none of the three eligible vitamin E trials (246 participants) reported quantitative sensory testing. The eligible single trials involving acetylcysteine (14 participants), diethyldithiocarbamate (195 participants), oxcarbazepine (32 participants), and retinoic acid (92 participants) did not perform quantitative sensory testing. In all, this review includes data from 2906 participants. However, only seven trials reported data for the primary outcome measure of this review, (quantitative sensory testing) and only nine trials reported our objective secondary measure, nerve conduction test results. Additionally, methodological heterogeneity precluded pooling of the results in most cases. Nonetheless, a larger number of trials reported the results of secondary (non-quantitative and subjective) measures such as the National Cancer Institute Common Toxicity Criteria (NCI-CTC) for neuropathy (15 trials), and these results we pooled and reported as meta-analysis. Amifostine showed a significantly reduced risk of developing neurotoxicity NCI-CTC (or equivalent) ≥ 2 compared to placebo (RR 0.26, 95% CI 0.11 to 0.61). Glutathione was also efficacious with an RR of 0.29 (95% CI 0.10 to 0.85). In three vitamin E studies subjective measures not suitable for combination in meta analysis each favoured vitamin E. For other interventions the qualitative toxicity measures were either negative (N-acetyl cysteine, Ca/Mg, DDTC and retinoic acid) or not evaluated (oxcarbazepine and Org 2766).Adverse events were infrequent or not reported for most interventions. Amifostine was associated with transient hypotension in 8% to 62% of participants, retinoic acid with hypocalcaemia in 11%, and approximately 20% of participantss withdrew from treatment with DDTC because of toxicity.

AUTHORS' CONCLUSIONS

At present, the data are insufficient to conclude that any of the purported chemoprotective agents (acetylcysteine, amifostine, calcium and magnesium, diethyldithiocarbamate, glutathione, Org 2766, oxcarbazepine, retinoic acid, or vitamin E) prevent or limit the neurotoxicity of platin drugs among human patients, as determined using quantitative, objective measures of neuropathy. Amifostine, calcium and magnesium, glutathione, and vitamin E showed modest but promising (borderline statistically significant) results favouring their ability to reduce the neurotoxicity of cisplatin and related chemotherapies, as measured using secondary, non-quantitative and subjective measures such as the NCI-CTC neuropathy grading scale. Among these interventions, the efficacy of only vitamin E was evaluated using quantitative nerve conduction studies; the results were negative and did not support the positive findings based on the qualitative measures. In summary, the present studies are limited by the small number of participants receiving any particular agent, a lack of objective measures of neuropathy, and differing results among similar trials, which make it impossible to conclude that any of the neuroprotective agents tested prevent or limit the neurotoxicity of platinum drugs.

Strategies for optimizing the response of cancer and normal tissues to radiation

Approximately 50% of all patients with cancer receive radiation therapy at some point during the course of their treatment, and the majority of these patients are treated with curative intent. Despite recent advances in the planning of radiation treatment and the delivery of image-guided radiation therapy, acute toxicity and potential long-term side effects often limit the ability to deliver a sufficient dose of radiation to control tumours locally. In the past two decades, a better understanding of the hallmarks of cancer and the discovery of specific signalling pathways by which cells respond to radiation have provided new opportunities to design molecularly targeted therapies to increase the therapeutic window of radiation therapy. Here, we review efforts to develop approaches that could improve outcomes with radiation therapy by increasing the probability of tumour cure or by decreasing normal tissue toxicity.

Regulators of global genome repair do not respond to DNA damaging therapy but correlate with survival in melanoma

Nucleotide excision repair (NER) orchestrates the repair of helix distorting DNA damage, induced by both ultraviolet radiation (UVR) and cisplatin. There is evidence that the global genome repair (GGR) arm of NER is dysfunctional in melanoma and it is known to have limited induction in melanoma cell lines after cisplatin treatment. The aims of this study were to examine mRNA transcript levels of regulators of GGR and to investigate the downstream effect on global transcript expression in melanoma cell lines after cisplatin treatment and in melanoma tumours. The GGR regulators, BRCA1 and PCNA, were induced in melanocytes after cisplatin, but not in melanoma cell lines. Transcripts associated with BRCA1, BRCA2, ATM and CHEK2 showed altered expression in melanoma cell lines after cisplatin treatment. In melanoma tumour tissue BRCA1 transcript expression correlated with poor survival and XPB expression correlated with solar elastosis levels. Taken together, these findings provide evidence of the mechanisms underlying NER deficiency in melanoma.

Melanoma: from darkness to promise

Metastatic melanoma is one of the most resistant tumors to standard chemotherapy approaches. The median overall survival of patients diagnosed with metastatic melanoma is lower than 9 months. Current approved treatments offer only marginal survival advantages. New immunotherapeutic targets have appeared recently trying to modulate the host immune response against the tumor. New targeted agents have changed the standard of care of other solid tumor types like breast cancer. Here, we discuss the new advances and achievements in the treatment of this highly resistant disease.

Interventions for preventing neuropathy caused by cisplatin and related compounds

BACKGROUND

Cisplatin and several related antineoplastic agents used to treat many types of solid tumors are neurotoxic, and most patients completing a full course of cisplatin chemotherapy develop a clinically detectable sensory neuropathy. Effective neuroprotective therapies have been sought.

OBJECTIVES

To examine the efficacy of purported chemoprotective agents to prevent or limit the neurotoxicity of cisplatin and related agents.

SEARCH STRATEGY

We searched the Cochrane Neuromuscular Disease Group Specialized Register (25 August 2010), the Cochrane Central Register of Controlled Trials (Issue 3, 2010 in The Cochrane Library), MEDLINE (January 1966 to August 2010), EMBASE (January 1980 to August 2010), LILACS (January 1982 to August 2010), CINAHL (January 1982 to August 2010) for randomized trials designed to evaluate neuroprotective agents used to prevent or limit neurotoxicity of cisplatin and related agents among human patients.

SELECTION CRITERIA

Quasi-randomized or randomized controlled trials whose participants received cisplatin (or related compounds) chemotherapy with or without a potential chemoprotectant (acetylcysteine, amifostine, ACTH, BNP7787, calcium and magnesium, diethyldithiocarbamate, glutathione, Org 2766, oxcarbazepine, or vitamin E) and were evaluated zero to six months after completing chemotherapy using quantitative sensory testing (primary) or other measures including nerve conduction studies or neurological impairment rating using validated scales (secondary).

DATA COLLECTION AND ANALYSIS

We identified 16 randomized trials involving five possible chemoprotective agents in the initial 2006 review. Each study was reviewed by two authors who extracted the data and reached consensus. The 2010 update identified 11 additional randomized trials consisting of nine possible chemoprotective agents, including three treatments (acetylcysteine, calcium and magnesium, and oxcarbazepine) not among those described in the 2006 review. The included trials in the updated review involved eight unrelated treatments and included many disparate measures of neuropathy, resulting in insufficient data for any one measure to combine the results in most instances.

MAIN RESULTS

One of four eligible amifostine trials (541 total participants in all four trials) used quantitative sensory testing and demonstrated a favorable outcome in terms of amifostine neuroprotection, but the vibration perception threshold result was based on data from only 14 participants receiving amifostine who completed the post-treatment evaluation and should be regarded with caution. Of the six eligible glutathione trials (354 participants), one used quantitative sensory testing but reported only qualitative analyses. Four eligible Org 2766 trials (311 participants) employed quantitative sensory testing reported disparate results; meta-analyses of three trials using comparable measures showed no significant vibration perception threshold neuroprotection. The remaining trial reported only descriptive analyses. The single eligible trials involving acetylcysteine (14 participants), diethyldithiocarbamate (195 participants), calcium and magnesium (33 participants), and oxcarbazepine (32 participants) and the two eligible trials involving vitamin E (57 participants) did not perform quantitative sensory testing. In all, data from 1,537 participants were included.

AUTHORS' CONCLUSIONS

At present, the data are insufficient to conclude that any of the purported chemoprotective agents (acetylcysteine, amifostine, calcium and magnesium, diethyldithiocarbamate, glutathione, Org 2766, oxycarbazepine, or Vitamin E) prevent or limit the neurotoxicity of platin drugs among human patients.

Nucleotide excision repair gene expression after Cisplatin treatment in melanoma

Two of the hallmark features of melanoma are its development as a result of chronic UV radiation exposure and the limited efficacy of cisplatin in the disease treatment. Both of these DNA-damaging agents result in large helix-distorting DNA damage that is recognized and repaired by nucleotide excision repair (NER). The aim of this study was to examine the expression of NER gene transcripts, p53, and p21 in melanoma cell lines treated with cisplatin compared with melanocytes. Basal expression of all genes was greater in the melanoma cell lines compared with melanocytes. Global genome repair (GGR) transcripts showed significantly decreased relative expression (RE) in melanoma cell lines 24 hours after cisplatin treatment. The basal RE of p53 was significantly higher in the melanoma cell lines compared with the melanocytes. However, induction of p53 was only significant in the melanocytes at 6 and 24 hours after cisplatin treatment. Inhibition of p53 expression significantly decreased the expression of all the GGR transcripts in melanocytes at 6 and 24 hours after cisplatin treatment. Although the RE levels were lower with p53 inhibition, the induction of the GGR genes was very similar to that in the control melanocytes and increased significantly across the time points. The findings from this study revealed reduced GGR transcript levels in melanoma cells 24 hours after cisplatin treatment. Our findings suggest a possible mechanistic explanation for the limited efficacy of cisplatin treatment and the possible role of UV light in melanoma.

Current research and development of chemotherapeutic agents for melanoma

Cutaneous malignant melanoma is the most lethal form of skin cancer and an increasingly common disease worldwide. It remains one of the most treatment-refractory malignancies. The current treatment options for patients with metastatic melanoma are limited and in most cases non-curative. This review focuses on conventional chemotherapeutic drugs for melanoma treatment, by a single or combinational agent approach, but also summarizes some potential novel phytoagents discovered from dietary vegetables or traditional herbal medicines as alternative options or future medicine for melanoma prevention. We explore the mode of actions of these natural phytoagents against metastatic melanoma.

HSPPC-96 vaccine in metastatic melanoma patients: from the state of the art to a possible future

Heat-shock proteins are highly conserved, stress-induced proteins with chaperone function for trafficking and delivering peptides within the different compartments of the cell. Tumor-derived heat-shock protein-peptide complexes (HSPPCs) can be used for vaccination against malignancies. In particular, the HSPPC-96-based vaccine vitespen (formerly Oncophage) is the first autologous cancer vaccine made from individual patients' tumors that has shown encouraging results in clinical trials. In Phase I and II clinical trials, this vaccine has shown activity on different malignancies, such as gastric cancer, colorectal cancer, pancreatic cancer, non-Hodgkin's lymphoma and chronic myelogenous leukemia. In Phase III clinical trials in melanoma and kidney cancer, it demonstrated an excellent safety profile with almost no toxicity. Heat-shock protein-based vaccines can be considered as a novel therapeutic approach with a promising role in cancer management.

Amifostine reduces the seminiferous epithelium damage in doxorubicin-treated prepubertal rats without improving the fertility status

BACKGROUND

Amifostine is an efficient cytoprotector against toxicity caused by some chemotherapeutic drugs. Doxorubicin, a potent anticancer anthracycline, is known to produce spermatogenic damage even in low doses. Although some studies have suggested that amifostine does not confer protection to doxorubicin-induced testicular damage, schedules and age of treatment have different approach depending on the protocol. Thus, we proposed to investigate the potential cytoprotective action of amifostine against the damage provoked by doxorubicin to prepubertal rat testes (30-day-old) by assessing some macro and microscopic morphometric parameters 15, 30 and 60 days after the treatment; for fertility evaluation, quantitative analyses of sperm parameters and reproductive competence in the adult phase were also carried out.

METHODS

Thirty-day-old male rats were distributed into four groups: Doxorubicin (5 mg/kg), Amifostine (400 mg/kg), Amifostine/Doxorubicin (amifostine 15 minutes before doxorubicin) and Sham Control (0.9% saline solution). "Standard One Way Anova" parametric and "Anova on Ranks" non-parametric tests were applied according to the behavior of the obtained data; significant differences were considered when p < 0.05.

RESULTS

The rats killed 30 and 60 days after doxorubicin treatment showed diminution of seminiferous epithelium height and reduction on the frequency of tubular sections containing at least one type of differentiated spermatogonia; reduction of sperm concentration and motility and an increase of sperm anomalous forms where observed in doxorubicin-treated animals. All these parameters were improved in the Amifostine/Doxorubicin group only when compared to Doxorubicin group. Such reduction, however, still remained below the values obtained from the Sham Control group. Nevertheless, the reproductive competence of doxorubicin-treated rats was not improved by amifostine pre-administration.

CONCLUSIONS

These results suggest that amifostine promotes a significant reduction of the doxorubicin long-term side effects on the seminiferous epithelium of prepubertal rats, which is reflected in the epidydimal fluid parameters in the adult phase. However, fertility status results suggest that such protection may not be effective against sperm DNA content damage. Further investigation of sperm DNA integrity must be carried out using amifostine and doxorubicin-treated experimental models.

Oncophage: step to the future for vaccine therapy in melanoma

Heat-shock proteins (HSPs) are a group of proteins whose expression is increased when the cells are exposed to elevated temperatures or other stressful conditions. This increase in expression is transcriptionally regulated. The function of HSPs is similar in virtually all living organisms, from bacteria to humans. Their expression also occur under non-stressful conditions, simply 'monitoring' the cell's proteins, i.e., they carry old proteins to the cell's 'recycling bin' and they help newly synthesized proteins fold properly. These activities are part of a cell's own repair system. HSPs are molecular chaperones for protein molecules. They are usually cytoplasmic proteins and they perform functions in various intracellular processes. Tumour-derived HSP-peptide complexes (HSPPCs) can be used for vaccination against malignancies. In particular, HSPPC-96 complex, called Vitespen (formerly Oncophage) is a HSPs-based vaccine made from individual patients' tumours with a promising role in cancer management. This vaccine has been extensively studied in Phase I and II clinical trials, showing activity on different malignancies, including gastric cancer, colorectal cancer, pancreatic cancer, non-Hodgkin's lymphoma and chronic myelogenous leukaemia. The vaccine has also been studied in Phase III clinical trials in melanoma and kidney cancer, showing an excellent safety profile with essentially no toxicity. Thus, HSP-based vaccines are a novel therapeutic approach with a promising role in cancer management.

A pilot study of addition of amifostine to melphalan, carboplatin, etoposide, and cyclophosphamide with autologous hematopoietic stem cell transplantation in pediatric solid tumors-A pediatric blood and marrow transplant consortium study

Limited information is available regarding the use of amifostine in pediatric hematopoietic stem cell transplant (HSCT) patients. Melphalan, carboplatin, etoposide +/- cyclophosphamide is a commonly used preparatory regimen in pediatric solid tumor HSCT. Therefore, we decided to determine the feasibility of the addition of amifostine (750 mg/m b.i.d. x 4 d) to melphalan (200 mg/m), carboplatin (1200 mg/m), and etoposide (800 mg/m) (level 1) and escalating doses of cyclophosphamide (3000 mg/m and 3800 mg/m, levels 2 and 3, respectively) followed by autologous HSCT. Thirty-two patients with a variety of pediatric solid tumors were studied. Seventeen patients were accrued at level 1, 9 at level 2, and 6 at level 3. Major toxicities during the administration of the preparatory regimen were hypocalcemia, emesis, and hypotension. Hypocalcemia required aggressive calcium supplementation during the conditioning phase. No dose limiting toxicities were encountered at level 3. Amifostine at 750 mg/m b.i.d. for 4 days can be administered with a double alkylator regimen consisting of melphalan (200 mg/m), cyclophosphamide (up to 3800 mg/m), carboplatin (1200 mg/m), and etoposide (800 mg/m) with manageable toxicities.

Toxicity prevention with amifostine in pediatric osteosarcoma patients treated with cisplatin and doxorubicin

Amifostine has emerged as a pancytoprotectant shown protection against nephrotoxicity, neurotoxicity and ototoxicity in preclinical studies.

METHODS

We designed a prospective comparative randomized trial to evaluate the cytoprotective effects of amifostine in patients with osteosarcoma receiving cisplatin and doxorrubicin. Patients were evaluated for renal, hearing and cardiac toxicity.

RESULTS

We included 28 patients, mean age was 11.6 years, five had metastatic disease. Fifteen patients received amifostine and 13 did not. 20% of patients receiving amifostine developed renal toxicity compared to 30% in the control group (p = 0.318). Grade 1 and 2 audiologic toxicity was present in 100% of the experimental group against 85% of the controls (p = 0.501). Grade 1 cardiac toxicity was present in 2 patients in the control group (p = 0.175). There were no statistical significant differences between the two groups for chemotherapy-related toxicity. Response to chemotherapy was significantly better in the amifostine group.

CONCLUSION

amifostine did not reduce the ototoxicity and nephrotoxicity of our treatment regime. It was not well tolerated due to emesis. It is a selective cytoprotectant without reducing the effect of chemotherapy.

Chemotherapy for metastatic melanoma: time for a change?

Melanoma is a neoplasm with a rising incidence. Early-stage melanoma is curable, but advanced, metastatic melanoma almost uniformly is fatal, and patients with such advanced disease have a short median survival. Systemic therapy remains unsatisfactory, inducing complete durable responses in a small minority of patients. For the current review, the authors focused on the current role of cytotoxic chemotherapy in the treatment of metastatic melanoma and the future prospects for improvements for multiagent chemotherapy and chemotherapy combined with immunomodulatory and/or molecularly targeted agents. They discuss roles of single-agent chemotherapy, combination chemotherapy, combinations of chemotherapy with immunomodulatory or hormone agents, biochemotherapy, and combination chemotherapy with targeted therapies.

Interventions for preventing neuropathy caused by cisplatin and related compounds

BACKGROUND

Cisplatin and several related antineoplastic agents used to treat many types of solid tumors are neurotoxic, and most patients completing a full course of cisplatin chemotherapy develop a clinically detectable sensory neuropathy. Effective neuroprotective therapies have been sought.

OBJECTIVES

To examine the efficacy of purported chemoprotective agents to prevent or limit the neurotoxicity of cisplatin and related agents among human patients.

SEARCH STRATEGY

We searched the Cochrane Neuromuscular Disease Group Register (January 2005), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 1 2005), MEDLINE from (January 1966 to March 2005), EMBASE (from January 1980 to March 2005), LILACS (from January 1982 to March 2005), CINAHL (from January 1982 to March 2005) for randomized trials designed to evaluate neuroprotective agents used to prevent or limit neurotoxicity of cisplatin and related agents among human patients.

SELECTION CRITERIA

Quasi-randomized or randomized controlled trials whose participants received cisplatin (or related compounds) chemotherapy with or without a potential neuroprotectant (amifostine, diethyldithiocarbamate, glutathione, Org 2766, or vitamin E) and were evaluated zero to six months after completing chemotherapy using quantitative sensory testing (primary) or other measures including nerve conduction studies or neurological impairment rating using validated scales (secondary).

DATA COLLECTION AND ANALYSIS

We identified 16 randomized trials involving five possible chemoprotective agents. Each study was reviewed by two authors who extracted the data and reached consensus. The included trials involved five unrelated treatments and included many disparate measures of neuropathy, resulting in insufficient data for any one measure to combine the results in most instances.

MAIN RESULTS

The one of five eligible amifostine trials (541 participants) using quantitative sensory testing demonstrated a favorable outcome in terms of amifostine neuroprotection, but the subclinical result was based on 14 participants receiving amifostine. Of the five eligible glutathione trials (327 participants), one used quantitative sensory testing but reported only qualitative analyses. Four eligible Org 2766 trials (311 participants) employed quantitative sensory testing reported disparate results; meta-analyses of three trials using comparable measures showed no significant vibration perception threshold neuroprotection. The remaining trial reported only descriptive analyses. The one eligible diethyldithiocarbamate trial (214 participants) and the one eligible vitamin E trial (27 participants) did not perform quantitative sensory testing.

AUTHORS' CONCLUSIONS

At present, the data are insufficient to conclude if any of the purported neuroprotective agents (amifostine, diethyldithiocarbamate, glutathione, Org 2766, or Vitamin E) prevent or limit the neurotoxicity of platin drugs among human patients.

Treatment of metastatic malignant melanoma

The rapid increase in incidence of malignant melanoma has not been associated with better therapeutic options over the years. Single-agent chemotherapy or immunotherapy remain the treatments of choice when systemic therapy is offered. Dacarbazine (DTIC) is the chemotherapy of choice with a response rate of 16%. Other chemotherapies, including cisplatinum, paclitaxel, docetaxel and the DTIC analogue temozolomide, have shown activity in this disease. Based on their single-agent activity, several combination chemotherapies have been investigated with preliminary results that appeared promising. However, in randomized phase III trials the two most active chemotherapy combination regimens, cisplatin, vinblastine, and DTIC (CVD) and the Dartmouth regimen (DTIC, cisplatin, bischloroethylnitrosourea , and tamoxifen), did not prove to be superior to single-agent DTIC for overall survival. Immunotherapy with either interleukin (IL)-2 or interferon (IFN) has demonstrated response rates of 10% to 15% in appropriately selected patients. In patients who achieve a complete response, responses can be of greater durability than those with chemotherapy. However, IL-2 and IFN administration are associated with multiple side effects, and only physicians experienced in the management of such therapies should administer them. The potential benefit of combining chemotherapy with immunotherapy has led to multiple phase II trials of biochemotherapy that appeared to be associated with higher response rates and longer median survivals. However, several phase III trials have been completed that have not consistently demonstrated an improvement in either response rates or overall survival, and these approaches to therapy cannot be routinely recommended outside the context of a clinical trial. The surgical resection of isolated metastatic disease has demonstrated an important palliative benefit in those patients who present with solitary single-organ disease with the exception of the liver. Radiation has an important role in the palliative management of brain metastasis and symptomatic bony metastasis. Both stereotactic radiosurgery and whole brain radiotherapy have been used alone and in combination to benefit patients in this troubling clinical circumstance. Isolated limb perfusion and a newer technique, isolated limb infusion have demonstrated high response rates for those uncommon patients who develop recurrent disease isolated to a limb. In our opinion, if complete metastasectomy is not feasible and in the absence of brain metastases, single-agent IL-2 is a good initial treatment choice in appropriately selected patients. Single-agent chemotherapy with DTIC is the treatment of choice for patients who are not candidates for IL-2. Adoptive immunotherapy combining nonmyeloablative chemotherapy with high-dose IL-2 is a potentially promising therapeutic strategy under investigation. Targeted therapy is also an area of promising development as single agents, in combination, and combined with chemotherapy. The latter will be the focus of at least one upcoming cooperative group phase III trial.

Mitotic Arrest, Apoptosis, and Sensitization to Chemotherapy of Melanomas by Methionine Deprivation Stress

Methionine deprivation stress (MDS) eliminates mitotic activity in melanoma cells regardless of stage, grade, or TP53 status, whereas it has a negligible effect on normal skin fibroblasts. In most cases, apoptosis accounts for the elimination of up to 90% of tumor cells from the culture within 72 hours after MDS, leaving a scattered population of multinucleated resistant cells. Loss of mitosis in tumor cells is associated with marked reduction of cyclin-dependent kinase (CDK) 1 transcription and/or loss of its active form (CDK1-P-Thr(161)), which is coincident with up-regulation of CDKN1A, CDKN1B, and CDKN1C (p21, p27, and p57). Expression of the proapoptotic LITAF, IFNGR, EREG, TNFSF/TNFRSF10 and TNFRSF12, FAS, and RNASEL is primarily up-regulated/induced in cells destined to undergo apoptosis. Loss of Aurora kinase B and BIRC5, which are required for histone H3 phosphorylation, is associated with the accumulation of surviving multinucleated cells. Nevertheless, noncycling survivors of MDS are sensitized to temozolomide, carmustin, and cisplatin to a much greater extent than normal skin fibroblasts possibly because of the suppression of MGMT/TOP1/POLB, MGMT/RAD52/RAD54, and cMET/RADD52, respectively. Sensitivity to these and additional genotoxic agents and radiation may also be acquired due to loss of cMET/OGG1, reduced glutathione reductase levels, and a G(2)-phase block that is a crucial step in the damage response associated with enhancement of drug toxicity. Although the genes controlling mitotic arrest and/or apoptosis in response to low extracellular methionine levels are unknown, it is likely that such control is exerted via the induction/up-regulation of tumor suppressors/growth inhibitor genes, such as TGFB, PTEN, GAS1, EGR3, BTG3, MDA7, and the proteoglycans (LUM, BGN, and DCN), as well as the down-regulation/loss of function of prosurvival genes, such as NFkappaB, MYC, and ERBB2. Although MDS targets several common genes in tumors, mutational variability among melanomas may decide which metabolic and signal transduction pathways will be activated or shutdown.

Surgical management of distant metastases

Although the location of metastases is of prognostic importance in stage IV melanoma, as seen in the revised AJCC staging classification system and other studies, certain guiding principles apply to patients who have any stage IV disease. Close follow-up of any patient who has melanoma may identify surgically resectable metastatic disease, although this method is controversial. Components of this monitoring may include careful questioning to determine symptoms, such as cough, abdominal pain, or headaches; physical examination for evidence of skin, soft tissue, and lymph node metastases; and screening tools, such as radiographs and laboratory tests. Identifying patients who have metastatic disease at the earliest stage possible is crucial for surgical resection to be an option. Patients should also be thoughtfully evaluated for the possibility of a complete surgical re-section. Complete metastectomy, regardless of the anatomic site, confers survival advantages not seen with other treatment modalities. This aggressive surgical approach should be tempered with the knowledge that incomplete resections put patients at increased risk without any proven survival benefit, and should be reserved only for palliation of symptoms. Systemic adjuvant therapies for stage IV melanoma are evolving, but do not yet confer the survival advantage of complete surgical resection. Until novel drug therapies show efficacy and significantly prolong survival in patients who have stage IV disease, careful consideration should be given to a complete metastectomy if technically feasible.

Induction of apoptosis in human lung cancer cells following treatment with amifostine and an adenoviral vector containing wild-type p53

Adenoviral delivery of the p53 gene is a potential therapeutic approach for the treatment of lung cancer. Furthermore, amifostine is a cytoprotective agent and recent reports have described its potentiation of chemotherapy's antitumor activity in lung cancer. Therefore, we wished to investigate the ability of amifostine both alone and in combination with p53-based therapy to induce apoptosis, and to understand the mechanisms by which this apoptosis occurs. Using p53 null and wild-type p53 human lung cancer cells and normal human bronchial epithelial cells, we evaluated the effects of amifostine on proliferation and apoptosis. We then analyzed Adp53 in combination with amifostine and performed isobologram analysis. Expression of p53, p21(WAF1), Bax, Bak, bcl-2, as well as total and phosphorylated Cdc2 in the absence and presence of olomoucine, a phosphorylated Cdc2 kinase inhibitor, was then determined. Amifostine-induced apoptosis in human lung cancer cells in a dose-dependent fashion. The combination of amifostine and Adp53 significantly enhanced, with a supra-additive effect, the inhibition of proliferation of lung cancer cells. This enhancement of apoptosis by amifostine was associated with activation of p53 and dephosphorylation of Cdc2 proteins. Notably, olomoucine effectively prevented amifostine and/or Adp53-induced Cdc2 kinase activation and subsequent apoptosis. Our data shows that amifostine alone can induce apoptosis of human lung cancer cells, and that the combination of Adp53 with amifostine resulted in significantly higher levels of apoptosis. In addition, it appears that Cdc2 kinase plays an important role in the induction of apoptosis by amifostine and Adp53.

Management of Metastatic Melanoma 2005

The management of metastatic melanoma in 2005 remains a major clinical challenge. Multidisciplinary treatment planning and careful attention to sites of metastases, tumor biology, and comorbid conditions are critical to making the best clinical decisions for individual patients. No standard of care exists because no systemic therapies have yet shown efficacy in phase III trials. Single-agent or combination chemotherapy has not impacted over-all survival, and response rates are of short duration. High-dose IL-2 produces durable responses in a small subset (7%) of highly selected patients and has considerable toxicity and quality-of-life trade-offs. Biochemotherapy results in overall higher responses, but its impact on overall survival has been disappointing and its toxicity and expense are considerable. Re-searchers are further investigating biochemotherapy modifications with maintenance biotherapy and CNS consolidation in effort to increase durability of responses and prevent or delay the devastating sequela of CNS metastases. Despite a disappointing past, the advancement of science and a better understanding of critical cellular targets and pathways make the future of melanoma research encouraging. Clinical trials are actively studying novel immune potentiators, cytotoxics, and targeted therapies. Combinations of these new agents will likely be necessary to advance the treatment of the dis-ease. All patients should be encouraged to participate in clinical trials.

Amifostine does not protect against the ototoxicity of high-dose cisplatin combined with etoposide and bleomycin in pediatric germ-cell tumors: a Children's Oncology Group study

BACKGROUND

High-dose cisplatin combined with etoposide and bleomycin (HDPEB) improves event-free survival (EFS) in advanced pediatric germ-cell tumors (PGCT), but has significant ototoxicity. Amifostine appears to protect against toxicity. The authors combined amifostine with HDPEB and evaluated the efficacy and toxicity, specifically whether ototoxicity decreased.

METHODS

Eligibility criteria included age < 15 years and unresectable Stage III/IV extracranial, extragonadal PGCT. Patients received bleomycin 15 IU/m(2) on Day 1, then etoposide 100 mg/m(2) per day, amifostine 825 mg/m(2) per day, and cisplatin 40 mg/m(2)per day on Days 1-5, intravenously. The cycles were repeated every 3-4 weeks with imaging evaluation after 4 cycles. Patients with residual radiographic abnormalities underwent resection. Patients with residual tumor received two additional HDPEB cycles. Hearing evaluations were required at diagnosis and after two and four cycles. Audiologic results were reviewed and compared with historical controls treated with HDPEB.

RESULTS

Twenty-five eligible patients were enrolled between April 2000 and April 2002. Their median age was 1.6 years (range, 0.64-13.9 years), 17 patients were female, 11 had metastases, and 24 had a yolk sac carcinoma component histologically. Primary sites included sacrococcygeal area/pelvis (n = 15), vagina (n = 5), and other (n = 5). Two-year EFS and overall survival were 83.5% +/- 12.8% and 85.6% +/- 12.3%, respectively. Eight patients were removed from the study (four had progressive disease/disease recurrence and four had ototoxicity). Grade 3/4 toxicities included neutropenia (n = 20), thrombocytopenia (n = 14), electrolyte imbalances (n = 14), and gastrointestinal toxicity (n = 12). Twenty-four of 25 patients received hearing evaluations, and 75% had significant hearing loss.

CONCLUSIONS

Amifostine did not protect against HDPEB-associated ototoxicity.

Severe neurotoxicity, ototoxicity and nephrotoxicity following high-dose cisplatin and amifostine

Cisplatin in higher doses have been used routinely in the treatment of childhood tumours including neuroblastoma and germ cell tumors. Amifostine, a broad-spectrum cytoprotector of normal tissues, has been approved by U.S. Food and Drug Administration for use in patients receiving cisplatin. Such administration of amifostine has been reported to reduce cisplatin-related toxicities in some studies, but not all. The authors report a case of severe toxicity with cisplatin in a girl with epithelial cell carcinoma of the ovary despite the use of amifostine.

Otoproteção da amifostina aos efeitos ototóxicos da cisplatina: estudo em cobaias albinas por emissões otoacústicas produtos de distorção e microscopia eletrônica de varredura

A Cisplatina é uma potente droga antineoplásica, largamente utilizada para o tratamento do câncer, tanto em adultos quanto em crianças. Dentre seus efeitos colaterais, a ototoxicidade se apresenta como um dos mais importantes e leva à perda auditiva irreversível, bilateral, para as altas freqüências (4KHz -8KHz). Estudos têm tentado identificar drogas que, associadas à cisplatina, possam atuar como otoprotetores. Sabe-se que o mecanismo da ototoxicidade pela cisplatina está relacionado a alterações nos mecanismos antioxidantes das células ciliadas, principalmente as células ciliadas externas da cóclea. A amifostina tem conhecida ação antioxidante, com conhecido efeito otoprotetor aos efeitos lesivos da radioterapia. OBJETIVO: Nossa proposta foi avaliar através de emissões otoacústicas, por produtos de distorção (EOAPD) e por microscopia eletrônica de varredura (MEV), a existência de possível efeito otoprotetor da amifostina no tratamento com cisplatina. FORMA DE ESTUDO: Experimental. MATERIAL E MÉTODO: O estudo foi realizado em cobaias albinas, que foram divididas em três grupos: Grupo 1: 6 animais -12 orelhas - cisplatina 8,0 mg/Kg/dia (via intraperitoneal) por três dias; Grupo 2: 6 animais - 12 orelhas - amifostina 100 mg/Kg/ dia (via intraperitoneal) e 90 minutos após, cisplatina 8,0 mg/Kg/dia (via intraperitoneal) por três dias; Grupo 3: 03 animais - 06 orelhas - amifostina 100 mg/Kg/dia (via intraperitoneal) por três dias. RESULTADO: Encontramos EOAPD presentes e células ciliadas externas presentes, sem lesão anatômica a MEV, nos grupos 2 e 3. Concluímos que a amifostina, por sua ação antioxidante, atua como otoprotetor a ototoxicidade pela cisplatina. No entanto, seu uso não é recomendável nos casos de tumores potencialmente curáveis, por não se saber exatamente a influência da cisplatina na eficácia da quimioterapia.

Amifostine otoprotection to cisplatin ototoxicity: a guinea pig study using otoacoustic emission distortion products (DPOEA) and scanning electron microscopy

Cisplatin is an antineoplastic drug for cancer treatment in children and adults. The side effects of cisplatin ototoxicity are significant: irreversible bilateral hearing damage to high frequencies (4 kHz - 8 kHz). Reports recognize some drugs that are associated with cisplatin to obtain an otoprotector effect. The ototoxicity mechanisms of cisplatin are related to injury of hair cell oxidation mechanism, especially of outer hair cells. Aim: Using otoacoustic emissions distortion products (DPOEA) and scanning electron microscopy we intended to verify the action of amifostine, a radioprotective drug that has well known antioxidant characteristics and otoprotector effects to cisplatin injury. Study design: Experimental. Material and Method: We used an experimental guinea pig model. The study was performed as follows: group 1: 6 animals, 12 ears, cisplatin 8.0 mg/Kg/day (IP), 3 days. Group 2: 6 animals, 12 ears, amifostine 100 mg/Kg/day (IP) and after 90 minutes, cisplatin 8.0 mg/Kg/day (IP), 3 days and group 3: 3 animals, 6 ears, amifostine 100 mg/Kg/day (IP), 3 days. Results: DPOEA were present before and after treatment in groups 2 and 3. The normal cilium architecture of outer hair cells was supported in all cochlear turns in groups 2 and 3. We concluded that amifostine has a potential otoprotector effect against cisplatin ototoxicity and could be used in clinical trials.

DNA repair pathways in drug resistance in melanoma

Metastatic melanoma has a poor prognosis due to resistance to multiple chemotherapy regimens. The mainstay of treatment remains dacarbazine, with cisplatin being a commonly used alternative. Melanoma displays marked resistance to the DNA-damaging effects of these drugs. Intrinsic and acquired resistance involves multiple cellular pathways of damage recognition, repair and apoptosis. Increased understanding of these pathways is identifying novel targets that it is hoped will make inroads into the treatment of this lethal disease.

Amifostine for children with medulloblastoma treated with cisplatin-based chemotherapy

In adult patients, amifostine appears to ameliorate cisplatin-related nephrotoxicity and ototoxicity. We assessed the safety and efficacy of amifostine in 11 children with newly diagnosed medulloblastoma/primitive neuroectodermal tumor treated with radiotherapy and vincristine, lomustine, and cisplatin. Amifostine was administered immediately prior to and 4 hr into the cisplatin infusion. Amifostine caused assymptomatic hypotension and hypocalcemia in 18 and 82% of patients, respectively. Despite amifostine use, 78% of patients developed significant ototoxicity. Although relatively well tolerated, amifostine does not appear to have a major impact on ameliorating the risk of developing significant nephro- and ototoxicity in children with medulloblastoma. Larger studies will help clarify these findings.

WR-2721 (Amifostine) ameliorates cisplatin-induced hearing loss but causes neurotoxicity in hamsters: dose-dependent effects

Chemoprotective agents reduce the toxic side effects of chemotherapy agents such as cisplatin. The conventional belief is that the chemoprotective agent WR-2721 (Amifostine), while protecting against most cisplatin-induced side effects, does not protect against cisplatin-induced ototoxicity (i.e., hearing loss). There is no knowledge, however, about the efficacy of high doses of WR-2721 (WR) in possibly protecting against cisplatin-induced ototoxicity. Thus, the dose-dependent effects of WR in possibly ameliorating cisplatin-induced ototoxicity were investigated. Hamsters were given a series of 5 cisplatin injections (3 mg/kg/injection once every other day, i.p.) either alone or in combination with 18, 40, 80, or 400 mg/kg/injection of the rescue agent WR ( n = 5 or 10/group). Other groups received either 80 mg/kg/injection WR alone ( n = 5) or were untreated ( n = 14). Ototoxicity was assessed by auditory brain stem responses (ABR). WR provided dose-dependent rescue from cisplatin's ototoxicity with no protection at the low dose of 18 mg/kg, moderate protection at 40 mg/kg, and nearly complete protection at 80 and 400 mg/kg. However, WR doses of 40 mg/kg or higher caused neurotoxicity as evidenced by prolongations in the ABR's interpeak latencies. Thus, high doses of WR provided the beneficial effect of protecting against cisplatin-induced ototoxicity, but had the harmful side effect of neurotoxicity. Previous failures to find chemoprotection from cisplatin-induced ototoxicity were likely due to the use of WR doses that were too small. The clinical implications of the beneficial and harmful effects of high doses of WR are discussed.

Comparative study between the interaction of dephosphorylated amifostine (WR-1065) and amoxicilline with pBR322 in absence and presence of cisplatin by AFM

The effect of the amoxicilline as a possible cisplatin-action protector on pBR322 DNA has been visually studied by atomic force microscopy in comparison with the modifications caused by the controversed cisplatin protector amifostine. Incubation of amoxicilline with the plasmid DNA showed aggregation and compaction of DNA. Cisplatin incubated in the same conditions with DNA produced kinks and super-coiling of the circular form. In the case of previous treatment of DNA with amoxicilline, the characteristic effect of cisplatin is only partially observed. The amoxicilline seemed to control the action of cisplatin on DNA. The initial effect of dephosphorylated amifostine (WR-1065) when this protector was incubated with the plasmid was also the formation of aggregates and the compaction of DNA. However, addition of cisplatin successively after 1 and 2 h showed the characteristic modification caused by cisplatin but only in a decreasing percentage of molecules of DNA. Both molecules, amoxicilline and WR-1065 seem to control the strong direct action of cisplatin on DNA. This effect can justify the role as protecting agent of amifostine on side effects caused by cisplatin and can open new possibilities to other agents like amoxicilline.

Limited access trial using amifostine for protection against cisplatin- and three-hour paclitaxel-induced neurotoxicity: a phase II study of the Gynecologic Oncology Group

PURPOSE

The purpose of this study was to determine whether amifostine (WR-2721) prevents or ameliorates clinically significant (grade 2 to 4) neurotoxicity associated with cisplatin and 3-hour paclitaxel chemotherapy.

MATERIALS AND METHODS

The chemotherapy program consisted of intravenous paclitaxel 175 mg/m2 over 3 hours followed by amifostine 740 mg/m2 and cisplatin 75 mg/m2 administered over 90 minutes beginning 15 minutes after amifostine administration. At baseline, before each treatment cycle, and for 3 months after completing chemotherapy, patients were evaluated for evidence of neurotoxicity and other treatment-related adverse effects using three methods: standard clinical evaluation (National Cancer Institute common toxicity criteria [CTC] grading), a neurotoxicity questionnaire to assess symptoms and limitations imposed by peripheral neuropathy, and vibration perception threshold (VPT) testing.

RESULTS

Four of 27 assessable patients developed grade 2 to 4 neurotoxicity based on clinical assessments and CTC grading. This number of neuropathic events exceeded the predetermined threshold level for a second stage of accrual and the study was closed.

CONCLUSION

Amifostine's level of activity in this trial was insufficient to warrant further study in a phase III trial. Based on the receiver operating characteristic analysis, it would appear that VPT measurements are less sensitive to the development of peripheral neuropathy than the neurotoxicity questionnaire. The questionnaire, referred to as the Functional Assessment of Cancer Therapy/Gynecologic Oncology Group-Neurotoxicity, may be used instead of VPT measurements in future studies of chemotherapy-induced peripheral neuropathy.

Phase II randomized trial of cisplatin and WR-2721 versus cisplatin alone for metastatic melanoma

This study was designed to evaluate the toxicity and efficacy of cisplatin and WR-2721 in contrast to cisplatin alone for the therapy of measurable metastatic melanoma. Ninety-four patients with metastatic melanoma were randomized to receive either cisplatin at a dose of 150 mg/m2 and WR-2721 at a dose of 910 mg/m2, or cisplatin alone at a dose of 120 mg/m2. WR-2721 did not mitigate the toxic effects of cisplatin, and toxicity was increased in the WR-2721 plus cisplatin arm compared with cisplatin alone. For patients receiving cisplatin alone, the response rate was 16.3%; for those receiving cisplatin plus WR-2721, the response rate was 23.3%. The duration of response was 7.3 months. Median survival in the intent-to-treat analysis was 7.58 months. The study was terminated after accrual of 94 patients, with inadequate power to define an effect of WR-2721 on the duration of response and survival. In conclusion, cisplatin with WR-2721 showed an improved response rate over cisplatin alone. The lack of improved duration of response or impact on survival may be the result of the limited improvement of efficacy with the higher dosage of cisplatin in conjunction with WR-2721, or the limited number of patients accrued to this study. These factors, coupled with the failure of the combination to diminish toxicity, dampen enthusiasm for this combination.

Amifostine pretreatment for protection against topotecan-induced hematologic toxicity: results of a multicenter phase III trial in patients with advanced gynecologic malignancies

OBJECTIVE

To determine if amifostine could reduce the hematologic toxicity associated with topotecan.

METHODS

Thirty patients with recurrent/refractory gynecologic malignancies were randomized to receive topotecan (TOPO) (1.5 mg/m(2)/day days 1-5) with or without amifostine (AMI/TOPO) (500 mg/m(2)/day days 1-5) every 3 weeks for six cycles. The primary study endpoints were the incidence of grade 3 and 4 neutropenia.

RESULTS

Fifteen patients were randomized to each arm for a total of 49 TOPO and 53 AMI/TOPO cycles. Patient characteristics and pretreatment ANC were similar between groups. Topotecan 1.5 mg/m(2)/day days 1-5 was initially administered to seven patients. Five developed neutropenic fevers, one an uncomplicated grade 4 neutropenia, and the other an uncomplicated grade 3 neutropenia. There were two treatment-related deaths due to sepsis (one in each treatment arm). The starting dose was thereafter reduced to 1.25 mg/m(2)/day days 1-5 every 21 days. No treatment related deaths occurred after this dose reduction. The incidence of combined grade 3/4 neutropenia was reduced from 67% (33/49 cycles) to 38% (20/53 cycles) with the addition of amifostine (P = 0.003; OR 0.29; 95% CI 0.12-0.71).

CONCLUSIONS

Topotecan at 1.5 mg/m(2)/day days 1-5 in heavily pretreated patients resulted in excessive toxicity not manageable with amifostine. At the reduced topotecan dose (1.25 mg/m(2) x 5 days), pretreatment with amifostine reduced the hematologic toxicity associated with topotecan chemotherapy in women with recurrent/refractory gynecologic malignancies.