Phase III multicenter randomized trial of the Dartmouth regimen versus dacarbazine in patients with metastatic melanoma

A phase II study of high dose tamoxifen and weekly cisplatin in patients with metastatic melanoma

We have previously demonstrated that the combination of tamoxifen and cisplatin has activity in patients with metastatic melanoma. In vitro studies have demonstrated that tamoxifen and cisplatin exhibit cytotoxic synergy in human melanoma cells and that this interaction is dependent on a tamoxifen effect. The mechanism of this effect is currently under investigation in in vitro studies. In an attempt to improve the complete response rate of this regimen, we initiated a phase II trial to determine the effect of the use of high dose tamoxifen and weekly cisplatin on the complete response rate, disease-free survival and overall survival. Tamoxifen was started on day 1 initially at a dose of 240 mg/day and continued until the patient was taken off treatment. This dose was subsequently lowered to 200 mg/day. Cisplatin (80 mg/m2) was begun on day 2 and repeated weekly for a total of 3 weeks. During week 4, the patient was not treated with cisplatin but was evaluated for response. If disease stabilization or regression was documented, the patient received a second 3 week cycle of cisplatin and was then re-evaluated for response. Patients with progressive disease at any evaluation were removed from the study. In 28 consecutive patients, the overall response rate was 32% (95% confidence interval 15.88-52.35%). One patient achieved a complete remission that lasted 22 months. All other responses were partial in nature. Toxicity was primarily nausea and vomiting. Two patients developed grade 2 renal toxicity. There were no episodes of deep venous thrombosis. This phase II study demonstrates that this combination has modest activity in patients with metastatic melanoma. However, this study failed to confirm our hypothesis that high dose tamoxifen would increase the complete response rate of this combination. While this combination has activity, the overall response rate is not significantly better that that observed with the original Dartmouth regimen and the toxicity is substantial. We do not recommend this dose and schedule for routine clinical use.

Chemoimmunotherapy for melanoma with dacarbazine and 2,4-dinitrochlorobenzene: results from a murine tumour model

An empirically established chemoimmunotherapy that combines the epifocal application of the contact sensitizer dinitrochlorobenzene (DNCB) to cutaneous metastases with the systemic administration of dacarbazine (DTIC) yields high response rates and results in prolonged survival. However, despite the fact that this therapy has been in clinical use for several years, the mode of action still remains elusive. In order to overcome this limitation we established a murine model system. B16 melanoma cells were implanted subcutaneously in syngeneic C57BL/6 mice and treatment was started 7 days after. In a first set of experiments mice received intraperitoneal injections of DTIC followed by epifocal applications of DNCB 24 h later. Treatment significantly decreased tumour growth. In contrast, no significant effect was induced by DTIC or DNCB alone. Using this regimen, with varying doses of either DTIC or DNCB, we demonstrated that the therapeutic effect is dose dependent. Furthermore, the treatment of subcutaneous tumours with DTIC and DNCB influenced the course of visceral metastases: the growth of pulmonary metastases was significantly inhibited if subcutaneous tumours were treated as described. In conclusion, we have established a model system that seems to be appropriate for both the optimization of this therapeutic regimen and the characterization of effector mechanisms.

Temozolomide: a novel oral alkylating agent

Temozolomide is an imidazotetrazine with a mechanism of action and efficacy similar to dacarbazine (DTIC). However, it differs from DTIC in that it can be taken orally, degrades spontaneously to an active metabolite and penetrates the blood-brain barrier. It is well tolerated, making it a suitable candidate for combination chemotherapy. Trials to date have focussed on its activity in advanced metastatic melanoma and high-grade malignant glioma. Investigations into other indications, in particular solid tumors with central nervous system metastases, are ongoing. Studies of new drug schedules and of drugs to ameliorate temozolomide resistance offer the prospect of increased efficacy.

Recent advances in melanoma research

Recent advancement in the research of malignant melanoma is reviewed. Among many gene alterations detected in human melanoma, defect of CDKN2A located at chromosome 9p21 seems to be most important in the earlier developmental phase, though significance of this gene in the evolution of melanoma in situ has not been confirmed yet. Deletions of PTEN/MMAC1 on 10q23.3 and AIM1 on 6q21 as well as mutations of ras gene are involved in the later progression stages of melanoma. Adhesion molecules relevant to development and progression of melanoma have been intensely investigated in recent years, revealing crucial roles of cadherins and alpha(v)beta(3) integrin in the biologic behaviors of melanoma cells. Melanoma is characterized by extremely high potential of developing metastases. Dynamic changes of matrix metalloproteinase activity during invasion and movement of melanoma cells may be a major concern in this field. Fragility of blood vessels in melanoma lesions is another important point related to hematogeneous metastases. Acral lentiginous melanoma is a unique subtype of melanoma, because, in contrast to other subtypes, ultraviolet irradiation is not a major factor in its development. Investigation of pathogenesis of acral lentiginous melanoma surely provides us with new information about mechanism of melanocyte transformation. Recent advances in the management of malignant melanoma are also briefly reviewed, such as biochemotherapy, immunotherapy, and gene therapy. Finally, the concept of molecular classification of melanoma by gene expression profile is introduced, which possibly enables us to give the tailor-made therapy for each melanoma patient in the near future.

Dacarbazine and interferon alpha with or without interleukin 2 in metastatic melanoma: a randomized phase III multicentre trial of the Dermatologic Cooperative Oncology Group (DeCOG)

In several phase II-trials encouraging tumour responses rates in advanced metastatic melanoma (stage IV; AJCC-classification) have been reported for the application of biochemotherapy containing interleukin 2. This study was designed to compare the efficacy of therapy with dacarbazine (DTIC) and interferon alpha (IFN-alpha) only to that of therapy with DTIC and IFN-alpha with the addition of interleukin 2 (IL-2) in terms of the overall survival time and rate of objective remissions and to provide an elaborated toxicity profile for both types of therapy. 290 patients were randomized to receive either DTIC (850 mg/m(2)every 28 days) plus IFN-alpha2a/b (3 MIU/m(2), twice on day 1, once daily from days 2 to 5; 5 MIU/m(2)3 times a week from week 2 to 4) with or without IL-2 (4.5 MIU/m(2)for 3 hours i.v. on day 3; 9.0 MIU/m(2) i.v. day 3/4; 4.5 MIU/m(2) s.c. days 4 to 7). The treatment plan required at least 2 treatment cycles (8 weeks of therapy) for every patient. Of 290 randomized patients 281 were eligible for an intention-to-treat analysis. There was no difference in terms of survival time from treatment onset between the two arms (median 11.0 months each). In 273 patients treated according to protocol tumour response was assessable. The response rates did not differ between both arms (P = 0.87) with 18.0% objective responses (9.7% PR; 8.3% CR) for DTIC plus IFN-alpha as compared to 16.1% (8.8% PR; 7.3% CR) for DTIC, IFN-alpha and IL-2. Treatment cessation due to adverse reactions was significantly more common in patients receiving IL-2 (13.9%) than in patients receiving DTIC/IFN-alpha only (5.6%). In conclusion, there was neither a difference in survival time nor in tumour response rates when IL-2, applied according to the combined intravenous and subcutaneous schedule used for this study, was added to DTIC and IFN-alpha. However, toxicity was increased in melanoma patients treated with IL-2. Further phase III trials with continuous infusion and higher dosages must be performed before any final conclusions can be drawn on the potential usefulness of IL-2 in biochemotherapy of advanced melanoma.

Phase II randomized study of dacarbazine, carmustine, cisplatin and tamoxifen versus dacarbazine alone in advanced melanoma patients

This randomized phase II trial was performed to define the activity and toxicity of the combination of dacarbazine (DTIC), carmustine (BCNU), cisplatin (DDP) and tamoxifen (DBDT regimen) versus DTIC alone in patients with metastatic melanoma. Sixty patients with metastatic melanoma were randomly assigned to receive BCNU 150 mg/m2 intravenously (i.v.) on day 1, cisplatin 25 mg/m2 i.v. daily on days 1 to 3, DTIC 220 mg/m2 i.v. daily on days 1 to 3 and tamoxifen 160 mg orally daily for 7 days prior to chemotherapy (DBDT arm; arm A). Treatment cycles were repeated every 28 days, while BCNU was given every two cycles. The DTIC arm (arm B) patients received DTIC alone 1200 mg/m2 i.v. on day 1, repeated every 21 days. Patients were evaluated every two cycles; responding patients continued the treatment for a maximum of 12 cycles. The overall response rate was 26% in the DBDT arm and 5% in the DTIC arm. Complete responses were 2.5% for DBDT and 0% for DTIC. The median progression-free survival and the median survival were 4 and 9 months, respectively for DBDT, and 2 and 7 months for DTIC. DBDT was associated with significant haematological toxicity: 33% of the patients experienced a grade III or IV neutropenia and 28% a grade III or IV thrombocytopenia. In conclusion, the overall response rate obtained with DBDT was greater than that obtained with DTIC alone; however, this combination increases toxicity with limited impact on overall survival.

A standardization method to adjust for the effect of patient selection in phase II clinical trials

New combination regimens evaluated in phase II cancer clinical trials often show promising results compared to the standard therapy for a disease system. Selection of patients with a better prognosis can be a prominent factor for this optimism. For most disease systems, prognostic variables that are related to the outcome are available and are called risk factors. Patients are classified into risk categories depending on the number of risk factors they possess. The patient distribution is defined as the proportion of patients falling into each of these risk categories. Typically, the patient distribution observed for a phase II study differs from the standard therapy reports so that the outcomes are not comparable. A randomized trial is the ultimate step for establishing the efficacy of a new treatment. In order to determine whether a regimen should progress to a phase III trial, we suggest adjusting the standard therapy outcome for the effect of the observed phase II patient distribution. If the endpoint of interest is tumour response proportion, a weighted average utilizing the standard therapy response proportions and the phase II patient distribution would provide an estimate of the adjusted standard therapy response proportion. Confirmatory phase II trials often attempt to estimate median survival in addition to response proportion, since this is the primary endpoint for most phase III cancer studies. Because data are censored, we propose an adjustment method based on the bootstrap resampling technique. We illustrate the problem of disparate patient selection with data from melanoma studies and demonstrate the usefulness of the proposed adjustment method with data from bladder cancer studies. A simulation study indicates that the magnitude of the adjustment is heavily dependent on the degree of separation of the risk categories. SAS code is available on a website (http://lib.stat.cmu.edu) for easy implementation.

Cohort study of metastatic melanoma patients in the Dermatology Institute of Florence 1990/1997

BACKGROUND

Chemotherapy and immunotherapy are treatments currently employed in advanced melanoma, but responses obtained are poor, and metastatic melanoma patients with visceral localization rarely survive for more than 6 months. Thus, different therapeutic regimens are used in metastatic melanoma and no standardized therapy exists so far.

METHODS

We report a retrospective survival study involving 80 patients with metastatic melanoma who were treated either with chemotherapy [dacarbazine (DTIC) alone or DTIC in monotherapeutic or polychemotherapeutic regimen] or immunochemotherapy [interferon (IFN)-alpha at low doses added to chemotherapy]. Survival of patients was statistically evaluated in an actuarial curve taking into account as predictive variables sex, age, marital status, site of primary tumour, histological type, Clark level, sites of metastases, and the different therapeutic regimens (i.e. DTIC alone, DTIC plus IFN-alpha, or others, with or without IFN-alpha).

RESULTS

Site of primary melanoma, histological type, Clark level and therapy regimen appeared to exhibit a prognostic significance in survival; when a multivariate analysis was performed to obtain a mutual adjustment of survival values for each variable, only the therapeutic regimen was found to be significant as an independent prognostic variable. Patients treated with immunochemotherapy, i.e. DTIC plus IFN-alpha, showed a probability of dying of 0.41 (95% confidence interval 0.2-0.8) compared with patients treated with DTIC alone.

CONCLUSIONS

In our study immunochemotherapy, comprised of DTIC plus IFN-alpha at low doses, was associated with a significantly longer survival of patients, in comparison with chemotherapy comprised of only DTIC.

Chemosensitisation of malignant melanoma by BCL2 antisense therapy

BACKGROUND

Chemoresistance of malignant melanoma has been linked to expression of the proto-oncogene BCL2. Antisense oligonucleotides (ASO) targeted against BCL2 mRNA decreased BCL2 protein concentrations, increased tumour-cell apoptosis, and led to tumour responses in a mouse xenotransplantation model when combined with systemic dacarbazine. This phase I-II clinical study investigated the combination of BCL2 ASO (augmerosen, Genasense, G3139) and dacarbazine in patients with advanced malignant melanoma expressing BCL2.

METHODS

In a within-patient dose-escalation protocol, 14 patients with advanced malignant melanoma were given augmerosen intravenously or subcutaneously in daily doses of 0.6-6.5 mg/kg plus standard dacarbazine treatment (total doses up to 1000 mg/m2 per cycle). Toxicity was scored by common toxicity criteria. Plasma augmerosen concentrations were assayed by high-performance liquid chromatography. In serial tumour biopsy samples, BCL2 protein concentrations were measured by western blotting and tumour-cell apoptosis was assessed.

FINDINGS

The combination regimen was well tolerated, with no dose-limiting toxicity. Haematological abnormalities were mild to moderate. Lymphopenia was common, but no febrile neutropenia occurred. Higher doses of augmerosen were associated with transient fever. Four patients had liver-function abnormalities that resolved within 1 week. Steady-state plasma concentrations of augmerosen were attained within 24 h, and increased with administered dose. By day 5, daily doses of 1.7 mg/kg and higher led to a median 40% decrease in BCL2 protein in melanoma samples compared with baseline, concomitantly with increased tumour-cell apoptosis, which was greatly increased after dacarbazine treatment. Six patients have shown antitumour responses (one complete, two partial, three minor). The estimated median survival of all patients now exceeds 12 months.

INTERPRETATION

Systemic administration of augmerosen downregulated the target BCL2 protein in metastatic cancer. Such downregulation of BCL2, combined with standard anticancer therapy, offers a new approach to the treatment of patients with resistant neoplasms.

Classical chemotherapy for metastatic melanoma

Despite a major effort in clinical research scrutinizing various treatment regimens for patients suffering from metastatic melanoma the prognosis for these patients still remains poor. The treatment options tested have ranged from monochemotherapy, polychemotherapeutic approaches including highly toxic regimens requiring autologous bone marrow rescue, immuno-modulatory therapies, e.g. defined cytokines such as interferon-alpha and interleukin-2 as well as vaccination therapy with dendritic cells or genetically modified tumour cells, and bio-chemotherapy. Although immuno-modulatory approaches are currently regarded as the most promising, to date no improved overall survival has been achieved by any of these measures especially if tested in large multicentre trials. The focus of this review will be on classical chemotherapy with emphasis on both cutaneous and uveal melanoma.

Temozolomide, a novel alkylating agent with activity in the central nervous system, may improve the treatment of advanced metastatic melanoma

Temozolomide (TMZ) is the first new chemotherapy agent to be approved for the treatment of high-grade malignant gliomas in more than 20 years. This novel oral alkylating agent has demonstrated promising activity not only in brain tumors, but in a variety of solid tumors, including malignant melanoma. TMZ is 100% bioavailable when taken orally and, because of its small size and lipophilic properties, it is able to cross the blood-brain barrier. Concentrations in the central nervous system are approximately 30% of plasma concentrations. Once it has entered the central nervous system, TMZ can be spontaneously converted to the active metabolite. These pharmacologic properties make it an ideal agent for treating central nervous system malignancies. In patients with advanced metastatic melanoma, brain metastases are a major cause of treatment failure. In this setting, TMZ has been shown to be as effective as dacarbazine, with a similar safety profile. More importantly, there is evidence to suggest that TMZ-treated patients have a lower incidence of central nervous system relapse compared with dacarbazine-treated patients. Therefore, TMZ is actively being investigated for the treatment and prevention of brain metastases in melanoma patients. TMZ may become an important part of treatment regimens for advanced metastatic melanoma.

A randomized phase III study comparing dacarbazine, BCNU, cisplatin and tamoxifen with dacarbazine and interferon in advanced melanoma

The purpose of this study was to compare the response rate, overall and 1-year survival in patients with advanced melanoma treated with a standard therapy, dacarbazine and interferon-alpha (DTIC/IFN), or combination chemotherapy, consisting of dacarbazine, BCNU, cisplatin and tamoxifen (DBCT). Treatment toxicity and time spent in hospital were secondary end points. One hundred and five patients (of whom 100 were eligible) were randomized to receive either DTIC/IFN or DBCT. The trial was designed to detect a 25% absolute difference in response rate or in 1-year survival with 80% power. There was no significant difference in response rate: this was 17.3% with DTIC/IFN and 26.4% with DBCT. Median overall survival was similar at 199 and 202 days respectively. One-year survival rate favoured standard treatment (30.6 vs 22.6%), but did not differ significantly between arms. DBCT was associated with significantly greater haematological toxicity, and a greater need for time spent in hospital (5.75 days/treatment cycle vs 2.29 with dacarbazine and interferon). DBCT combination therapy cannot be recommended as standard treatment for advanced melanoma. Dacarbazine remains the standard chemotherapy for this condition.