Clinical evaluation of recombinant interferon alfa-2a (Roferon-A) in metastatic melanoma using two different schedules

Developing combination strategies using PD-1 checkpoint inhibitors to treat cancer

More than 3000 clinical trials are evaluating the clinical activity of the PD-1 checkpoint inhibitors as monotherapies and in combinations with other cancer therapies [1]. The PD-1 checkpoint inhibitors are remarkable for their clinical activities in shrinking tumors across a wide range of tumor types, in causing durable responses, and in their tolerability. These attributes position them as favorable agents in clinical combinations. Historically, approaches to cancer therapy combinations focused on agents with orthogonal activities to avoid shared resistance mechanisms and shared toxicities. Although CTLA-4/PD-1 combinations have progressed based on possible immune interactions, additional approaches have used more orthogonal treatments such as standard of care chemotherapies and anti-angiogenesis inhibitors. Using the concept of independent activity pioneered by Bliss [2], examples of these approaches were compared. Both standard of care chemotherapy and anti-angiogenesis combinations show promising clinical activity above that predicted by the independent contributions of the agents tested on their own. In contrast, the combinations of CTLA4/PD-1 checkpoint inhibitors in renal cancer and melanoma show no more activity than that predicted by the independent contributions of the monotherapies. This update on approaches to the development of clinical combination therapies highlights the potential importance of combining PD-1 checkpoint inhibitors with a broad range of clinically active partners.

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.

Chemotherapy for Melanoma

Prior to the recent therapeutic advances, chemotherapy was the mainstay of treatment options for advanced-stage melanoma. A number of studies have investigated various chemotherapy combinations in order to expand on the clinical responses achieved with single-agent dacarbazine, but these have not demonstrated an improvement in overall survival. Similar objective responses were observed with the combination of carboplatin and paclitaxel as were seen with single-agent dacarbazine. The combination of chemotherapy and immunotherapy, known as biochemo-therapy, has shown high clinical responses; however, biochemo-therapy has not been shown to improve overall survival and resulted in increased toxicities. In contrast, palliation and long-term responses have been observed with localized treatment with isolated limb perfusion or infusion in limb-isolated disease. Although new, improved therapeutic options exist for first-line management of advanced-stage melanoma, chemotherapy may still be important in the palliative treatment of refractory, progressive, and relapsed melanoma. We review the various chemotherapy options available for use in the treatment and palliation of advanced-stage melanoma, discuss the important clinical trials supporting the treatment recommendations, and focus on the clinical circumstances in which treatment with chemotherapy is useful.

Paradigm Shift in Dendritic Cell-Based Immunotherapy: From in vitro Generated Monocyte-Derived DCs to Naturally Circulating DC Subsets

Dendritic cell (DC)-based immunotherapy employs the patients’ immune system to fight neoplastic lesions spread over the entire body. This makes it an important therapy option for patients suffering from metastatic melanoma, which is often resistant to chemotherapy. However, conventional cellular vaccination approaches, based on monocyte-derived DCs (moDCs), only achieved modest response rates despite continued optimization of various vaccination parameters. In addition, the generation of moDCs requires extensive ex vivo culturing conceivably hampering the immunogenicity of the vaccine. Recent studies, thus, focused on vaccines that make use of primary DCs. Though rare in the blood, these naturally circulating DCs can be readily isolated and activated thereby circumventing lengthy ex vivo culture periods. The first clinical trials not only showed increased survival rates but also the induction of diversified anti-cancer immune responses. Upcoming treatment paradigms aim to include several primary DC subsets in a single vaccine as pre-clinical studies identified synergistic effects between various antigen-presenting cells.

Preparation of bioactive interferon alpha-loaded polysaccharide nanoparticles using a new approach of temperature-induced water phase/water-phase emulsion

The aim of this study was to develop a temperature-induced polyethylene glycol (PEG) water phase/polysaccharide water-phase emulsion approach for preparing interferon alpha-2b (IFNα-2b)-loaded polysaccharide nanoparticles. IFNα-2b was first added to a mixture of an aqueous solution of PEG and polysaccharide. The mixture solution was stirred in a magnetic stirrer at a rate of 2000 rpm for 45 seconds at 0°C ± 0.5°C. The solution was then prefrozen at different temperatures. The polysaccharide and IFNα-2b partitioned in the polysaccharide phase were preferentially separated out as the dispersed phase from the mixture solution during the prefreezing process. Then the prefrozen sample was freeze-dried to powder form. In order to remove the PEG, the powder was washed with dichloromethane. Once IFNα-2b was loaded into the polysaccharide nanoparticles, these nanoparticles could gain resistance to vapor–water and water–oil interfaces to protect IFNα-2b. The antiviral activity of the polysaccharide nanoparticles in vitro was highly preserved (above 97%), while the antiviral activity of IFNα-2b–loaded polysaccharide nanoparticles using the control water-in-oil-in-water method was only 71%. The antiviral activity of the IFNα-2b from blood samples was also determined on the basis of the activity to inhibit the cytopathic effects of the Sindbis virus on Follicular Lymphoma cells (FL). The antiviral activity in vivo was also highly preserved (above 97%). These polysaccharide nanoparticles could be processed to different formulations according to clinical requirements.

Adjuvant therapy: melanoma

With an incidence that is increasing at 2–5% per year, cutaneous melanoma is an international scourge that disproportionately targets young individuals. Despite much research, the treatment of advanced disease is still quite challenging. Immunotherapy with high-dose interferon-α2b or interleukin-2 benefits a select group of patients in the adjuvant and metastatic settings, respectively, with significant attendant toxicity. Advances in the biology of malignant melanoma and the role of immunomodulatory therapy have produced advances that have stunned the field. In this paper, we review the data for the use of interferon-α2b in various dosing ranges, vaccine therapy, and the role of radiotherapy in the adjuvant setting for malignant melanoma. Recent trials in the metastatic setting using anticytoxic T-lymphocyte antigen-4 (anti-CTLA-4) monoclonal antibody therapy and BRAF inhibitor therapy have demonstrated clear benefit with prolongation of survival. Trials investigating combinations of these novel agents with existing immunomodulators are at present underway.

Interest in an original methodology to define the optimal dosage of interferon-alpha-2a in metastatic melanoma patients

Interferon-α-2a (IFNa) has proven antitumor activity in a variety of neoplastic diseases, but no clear modality of administration has been validated. The aim of our study was to estimate the optimal dose of continuous subcutaneous administration of IFNa in stage IV metastatic melanoma patients. An innovative dose-finding approach, combining phase I and phase II trials, was planned to evaluate the toxicity and efficacy of four dose levels of IFNa (3, 6, 9, and 12 MIU/day). Sixteen patients were enrolled in this study. Three patients were treated according to the dose-allocation rule with IFNa at 3 MIU/day, nine patients at 6 MIU/day, and four patients at 9 MIU/day. Dose-limiting toxicities were grade 3 in five patients (three at a dose level of 6 MIU/day and two at a dose level of 9 MIU/day). Four clinically relevant responses were obtained, one at dose level 3 MIU/day, one at a dose level of 6 MIU/day, and two at a dose level of 9 MIU/day. The three final responses, at dose levels of 6 and 9 MIU/day, were associated with a dose-limiting toxicity. A dose level of 6 MIU/day was well tolerated but did not reach the desired efficacy target of 20%, and a dose level of 9 MIU/day was estimated to be too toxic. This original dose-finding methodology made it possible to estimate the rate of toxicity and efficacy in a small sample of patients without toxicity associated with each dose level.

Update on therapy for melanoma: opportunities for patient selection and overcoming tumor resistance

The incidence of malignant melanoma is rising faster than any other malignancy. Although earlier stage patients can be cured with surgical resection with or without adjuvant therapy, a significant number of patients go on to develop disseminated disease. Currently, limited therapeutic options exist for patients with metastatic melanoma. Recent studies suggest that patient selection is feasible and may enable the restriction of treatment to those most likely to benefit. Additionally, several potential mechanisms of tumor resistance have been identified creating opportunities for circumventing them. This article will review current strategies for patient selection and overcoming therapeutic resistance. These strategies hold the promise of extending the clinical benefits of current therapies as well as facilitating the development of additional and more active treatments.

Clinical and immunologic effects of subcutaneously administered interleukin-12 and interferon alfa-2b: phase I trial of patients with metastatic renal cell carcinoma or malignant melanoma

PURPOSE

Interleukin-12 (IL-12) and interferon alfa-2b (IFN-alpha-2b) are pleiotropic cytokines with activity in renal cell carcinoma (RCC) and malignant melanoma (MM) as single agents. Preclinical studies suggest concurrent administration may have synergistic antitumor effects. We conducted a phase I trial of concurrent subcutaneous (SC) administration of IL-12 and IFN-alpha-2b in patients with metastatic RCC or MM to determine toxicity, maximum-tolerated dose, preliminary efficacy, and effects on chemokine/cytokine gene expression in peripheral blood mononuclear cells (PBMCs).

PATIENTS AND METHODS

Cohorts of three to six patients were treated with escalating doses of IL-12 (dose I, 100 ng/kg; dose II, 300 ng/kg; dose III, 500 ng/kg; dose IV, 500 ng/kg SC) given twice weekly and IFN-alpha-2b (dose I, 1.0 MU/m(2); dose II, 1.0 MU/m(2); dose III, 1.0 MU/m(2); dose IV, 3.0 MU/m(2) SC) three times weekly in 4-week cycles. Effects on gene expression were assessed by reverse transcriptase polymerase chain reaction.

RESULTS

Twenty-six patients (19 with RCC, seven with MM) were accrued at dose levels I (n = 3), II (n = 3), III (n = 13), and IV (n = 7). Dose-limiting toxicity included grades 3 and 4 hepatotoxicity and neutropenia/leukopenia. Patients received a median of three cycles of treatment. Two patients with RCC and one patient with MM had partial responses. Median survival was 13.8 months. Reverse transcriptase polymerase chain reaction on PBMCs revealed induction of IP-10, Mig, B7.1 (CD80), interleukin-5, and interferon gamma in selected patients.

CONCLUSION

Concurrent SC administration of IL-12 and IFN-alpha-2b is possible at the dose levels utilized. Recommended doses for phase II trials are 500 ng/kg IL-12 and 1.0 MU/m(2) IFN-alpha-2b. Consistent induction of IP-10 and Mig, as well as variable induction of B7.1, interleukin-5, and interferon gamma expression was noted in PBMCs.

Potential of interferon-alpha in solid tumours: part 1

Interferon-alpha (IFNalpha) is a pleiotropic cytokine with direct and indirect antitumour effects. These include prolongation of the cell cycle time of malignant cells, inhibition of biosynthetic enzymes and apoptosis, interaction with other cytokines, and immunomodulatory and antiangiogenic effects. The first clinical trials in solid tumours used crude preparations of natural IFNalpha and demonstrated that tumour regressions in solid tumours and haematological malignancies were possible. Since the advent of genetic engineering technology, recombinant (r) IFNalpha has been widely evaluated in solid tumours. This review discusses the use and potential of rIFNalpha in solid tumours; the first part focuses on malignant melanoma and metastatic renal cell carcinoma (RCC). In the adjuvant treatment of malignant melanoma, rIFNalpha has been tested in randomised trials in more than 6000 patients. High-dosage IFNalpha (> or =10MU) prolongs disease-free survival (DFS) but not overall survival (OS). Low-dosage IFNalpha (< or =3MU) has not been shown to prolong DFS or OS, and current data do not support its use outside clinical trials. The latest United Kingdom Co-ordinating Committee on Cancer Research meta-analysis of ten randomised trials that used adjuvant rIFNalpha has shown that there is a benefit in DFS but not OS. No conclusions can be reached for intermediate-dosage IFNalpha (5 to 10MU) until the mature results of the European Organization for Research and Treatment of Cancer (EORTC) study 18952 are available. In RCC, current evidence does not support the use of adjuvant IFNalpha. In metastatic malignant melanoma and RCC, reported response rates to rIFNalpha are approximately 15%. In a minority of responding patients, however, these responses can be long-standing. In metastatic malignant melanoma, IFNalpha combined with other cytotoxic agents with or without interleukin-2 has achieved high response rates but has not improved survival. In metastatic RCC, intermediate dosages of rIFNalpha should be used and therapy should probably be prolonged (>12 months); response depends on prognostic factors such as good performance status, whereas survival is affected by factors such as low tumour burden. Nephrectomy should therefore be considered in patients with good performance status prior to IFNalpha immunotherapy in advanced RCC, even in patients with metastatic disease. The toxicity of high-dosage IFNalpha and the lack of definite benefit on OS with high- or low-dosage IFNalpha do not support its use outside clinical trials. Data from the ongoing US Intergroup studies, the ongoing EORTC 18991 study (long-term therapy with pegylated IFNalpha) and mature data from EORTC 18952 (intermediate-dosage IFNalpha) will help establish the role of IFNalpha as adjuvant therapy in malignant melanoma.

Adjuvant therapy of malignant melanoma

High risk surgically resected melanoma is associated with a less than 50% 5-year survival. Adjuvant therapy is an appropriate treatment modality in this setting, and is more likely to be effective as the tumour burden here is small. Clinical observations of spontaneous tumour regressions and a highly variable rate of disease progression suggest a role of the immune system in the natural history of melanoma. Biological agents have therefore been the subjects of numerous adjuvant studies. Early, randomised controlled trials (RCTs) of Bacillus Calmette-Guerin (BCG), levamisole, Corynebacterium parvum, chemotherapy, isolated limb perfusion (ILP), radiotherapy, transfer factor (TF), megestrol acetate and vitamin A yielded largely negative results. Current trials focus on vaccines and the interferons. To date the latter is the only therapy to have shown a significant benefit in the prospective randomised controlled phase III setting. This report represents a systematic review of studies in adjuvant therapy in melanoma. Data from ongoing studies is awaited before a role for adjuvant agents in high risk melanoma is confirmed.

Adjuvant interferon-alpha in malignant melanoma: current status

High-risk surgically resected primary or loco-regional cutaneous malignant melanoma, although uncommon, can be associated with less than 50% 5-year survival; adjuvant therapy of proven efficacy is therefore appropriate. Since immunological control mechanisms seem to be important in the natural history of melanoma, biological agents have been the subject of many adjuvant studies. Most popular has been recombinant interferon. Well over 4000 patients have been entered into randomized studies. Results suggest that there may be a clinical benefit, most clearly in relapse-free but also perhaps in overall survival. More precise estimates of the magnitude of any benefits are needed. The doses, schedules and cost-benefits have yet to be fully evaluated. Interferon cannot yet be recommended as standard adjuvant therapy in high-risk malignant melanoma.

Enhancement of complement-dependent cytotoxicity by polyvalent melanoma cell vaccine (CancerVax): correlation with survival

BACKGROUND

Case control studies have demonstrated that administration of CancerVax, a polyvalent melanoma cell vaccine (PMCV), after complete resection of melanoma metastases produces a significant improvement in disease-free survival (DFS). Because PMCV has no direct cytotoxic effect on melanoma cells, the authors hypothesized that it prolongs survival by enhancing antibody-mediated antimelanoma cytotoxicity.

METHODS

One hundred melanoma patients participating in a trial of PMCV adjuvant therapy following complete resection of regional node metastases were randomly selected for study. Serum samples obtained immediately before (T0) and 4, 8, 12, and 16 weeks after initiation of PMCV adjuvant therapy were adsorbed with L-14 lymphoblastoid cells and then tested for in vitro complement-dependent cytotoxicity (CDC) against M-14 cells, a melanoma cell line not used in PMCV. CDC was expressed as percentage of total cells (n = 10,000) killed. Survival curves were estimated by the Kaplan-Meier method. Statistical analysis was performed by the signed rank sum test, Spearman test, log-rank test, and Cox proportional hazard regression.

RESULTS

Median CDC at T0 was 4.5% (range, 0% to 40%). Within 16 weeks after initiation of PMCV therapy, CDC had increased in 82 (82%) patients. The median increase of 7.5% (range, -9% to 39%) represented a highly significant change (signed rank sum test; P = .0001). At a median follow-up of 29 months (range, 6 to 92 months), the maximum increase in CDC (deltaCDC) as a continuous variable was significantly correlated with DFS (P = .0001). Median survival and 5-year DFS were more than 54 months and less than 54%, respectively, for patients with deltaCDC > or =10% (n = 44) but only 7 months and 14%, respectively, for those with deltaCDC <10% (n = 56; P = .0001). Multivariate analysis confirmed deltaCDC as the most significant independent variable associated with DFS following initiation of PMCV therapy (P = .0001).

CONCLUSION

PMCV therapy greatly enhances serum CDC against melanoma cells. This enhancement is directly correlated with DFS following initiation of vaccine therapy.

Systemic therapy in melanoma

The patient with surgically incurable melanoma presents a difficult problem for the medical oncologist. Single chemotherapeutic agents at conventional doses produce bona fide but infrequent remissions. The most active single agent for the treatment of metastatic melanoma is dacarbazine (DTIC). Until recently, combinations of drugs yielded no real improvement over treatment with the individual components. The combination of DTIC + carmustine (BCNU) + cisplatin + tamoxifen (the "Dartmouth regimen") appears to be more effective than DTIC alone, but prospective randomized trials comparing the two are still in progress. The contribution of tamoxifen to the observed results continues to be evaluated. Biological agents, such as interferon and interleukin-2, have lower overall response rates compared to chemotherapy regimens, but response duration appears to be longer. Chemotherapy combined with biotherapy offers the promise of higher response rates and long-term durable remissions. The results from high-dose regimens that use autologous bone marrow or peripheral stem cell support have not been sufficient to justify the added toxicity. Although advanced melanoma often is not curable with systemic therapy, the considered use of currently available regimens can induce clinically significant remissions and, possibly, prolong life in some patients.

The treatment of disseminated malignant melanoma with special reference to the role of interferons, vinca alkaloids and tamoxifen

Malignant melanoma continues to increase in incidence. While early melanoma is highly curable by surgical means, the prognosis of patients with more advanced lesions and/or metastatic disease remains poor. Conventional chemotherapy with dacarbazine has a low frequency and short duration of response. Alternative drugs with single-agent activity include vinca alkaloids, nitrosoureas, procarbazine and platinum compounds. The addition of tamoxifen to chemotherapy, particularly cisplatin-based chemotherapy, appears to be beneficial. Recent studies suggest that combination chemotherapy may give better outcomes than single-agent treatment. Significant clinical activity has also been demonstrated with the use of interferons, particularly interferon alpha, and also with IL-2. Two recent studies suggest that the addition of interferon to chemotherapy may be beneficial. In addition, specific active immunotherapy with tumour vaccines has shown promise. The optimal methods of combining these treatment methods, such as chemotherapy and biological response modifiers/immunotherapy, however, remain to be defined.

Treatment of metastatic melanoma with combined chemotherapy containing cisplatin, vinblastine and dacarbazine (CVD) and biotherapy using interleukin-2 and interferon-alpha

BACKGROUND

Metastatic melanoma is commonly treated with chemotherapy and/or biological agents used separately. In this study we have investigated the efficacy of combined chemotherapy using cisplatin, vinblastine, DTIC (CVD) and biological therapy using interleukin-2 (IL-2) and interferon-alpha (IFN-alpha) in patients with metastatic melanoma.

PATIENTS AND METHODS

All patients had advanced, inoperable melanoma without prior treatment with chemotherapy or biotherapy, a performance status of ECOG 0-2 and no evidence of symptomatic brain metastases. The CVD regimen consisted of cisplatin 20 mg/m2/d x 4, vinblastine 1.6 mg/m2/d x 5 and DTIC 800 mg/m2 x 1, repeated at 21-day intervals. The biotherapy regimen included IL-2, 9 x 10(6) IU/ m2/d x 4 days and IFN-alpha 5 x 10(6) U/m2/d SC x 5 days. The CVD and biotherapy regimens were integrated initially, in an alternating manner at 6-week intervals and subsequently, in a sequential fashion where patients were randomized to receive either CVD immediately followed by biotherapy (CVD/Bio) or the reverse sequence (Bio/CVD). Patients were admitted to the hospital for IL-2 administration and for monitoring and treatment of IL-2 induced side effects. The phase II results of the integrated therapy (biochemotherapy) studies were retrospectively compared to our previously reported results with the CVD regimen used alone.

RESULTS

The alternating biochemotherapy program was used in 40 patients and the sequential biochemotherapy was used in 62 patients. The alternating regimen produced 2 CRs and 11 PRs for an overall response rate of 33% among 39 evaluable patients. The sequential biochemotherapy produced 14 CRs and 23 PRs for an overall response rate of 60% (95% CI, 47% to 72%). The sequence of CVD/Bio resulted in a higher response rate (11 CRs + 11 PRs (69%)) compared to the Bio/CVD sequence (3 CRs + 12 PRs (50%)). Although the duration of PRs was short (median, 8 months), the median duration of CRs was 3+years and 10 of 16 CRs are currently disease free for periods of 3+ to 6+ years. The median survival of patients receiving sequential biochemotherapy was 13 months compared to 9 months for the CVD treated group (P = 0.04). Treatment with biochemotherapy was associated with severe toxicity including intense myelosuppression, infections, IL-2 induced constitutional toxicity and hypotension. However, the IL-2 induced toxicities were generally manageable on a regular ward, except for 15% of the patients who required transfer to an intensive care unit for treatment of complications associated with the treatment.

CONCLUSIONS

The sequential combination of CVD with IL-2 + IFN-alpha appears to have produced an increase in the number of durable responses in patients with metastatic melanoma. The toxicity of this program, although severe, was manageable. The biochemotherapy regimen produced an apparent increase in the median survival compared to that observed with the CVD regimen. However, a prospective comparison of these two regimens will be required to confirm these observations.

Cytokine therapy of malignant melanoma

Melanoma is a malignant neoplasia of melanocyte origin appearing mainly in the skin. About one third of all melanomas detected disseminate, with the metastatic spread occurring either via lymphatic or blood vessels. In the treatment of advanced melanoma the conventional chemotherapy or radiotherapy has not been very successful. Melanoma is known to have immunologically provocative features. In recent years immunological therapies, mainly cytokines, have been applied in the treatment of melanoma. The most widely used cytokines are Interferons and interleukin-2. These agents are used either alone or in combination with each other or with chemotherapeutics. Interferon and interleukin-2 therapies have yielded response rates of 15-20% on average, whereas combinations of immunotherapy and chemotherapy offer response rates as high as 50-60%. Unfortunately, average survival of patients with disseminated melanoma has been short, from 6 to 12 months. The immunotherapy approach has yielded some long-term responses and probably even a cure for a small proportion of patients. Understanding of basic mechanisms of tumour destruction by cytokines and new agents coming into clinical use will undoubtedly further improve treatment results.

Cytokine gene-modified vaccines in the therapy of cancer

Therapeutic strategies based on the insertion of cytokine genes into the genome of tumour cells, followed by vaccination with the resulting genetically modified, cytokine-producing cells, represent a new potential prospect for treatment of cancer patients. In this review, the concept of cytokine gene-modified cancer vaccines is discussed; the discussion is focused on the rationale, characterization, progress in the development, preclinical testing, and first clinical trials. An effort is made to analyse and integrate the results obtained in different experimental model systems in order to determine the needed approaches and directions for further research.

Intermittent interferon and polychemotherapy in metastatic melanoma

This study was conducted to evaluate the efficacy and the tolerability of a four-drug chemotherapy regimen combined with interferon alpha (IFN) in metastatic melanoma. Between March 1991 and August 1993, 55 patients with advanced melanoma were enrolled for the present multicentre phase II study. Forty-nine patients were eligible and evaluable for toxicity; 48 patients were evaluable for response. The treatment schedule consisted of a 5-day regimen of dacarbazine, vincristine, bleomycin and lomustine, plus 6 x 10(6) IU IFN alpha three times weekly subcutaneously for 2 weeks starting on day 8. The cycle was repeated on day 29. Among the 48 assessable patients, 16 objective responses were seen, yielding a response rate of 33% (95% confidence interval 20%-46%). Seven patients achieved a complete response (CR) of a median of 6+ months (range 1+ to 21+ months) and 9 patients achieved a partial response (PR) of a median of 9 months (range 4-13 months). The median overall survival was 12+ months (range 6+ to 23+ months) for the patients with CR and 15+ months (range 8-20 months) for the patients with PR. Even the survival of the 7 patients with stable disease was fairly long (median 12, range 7-17 months), appearing to be significantly longer than the survival of the 25 patients with progressive disease (median 5, range 1-24+ months). The treatment was moderately well tolerated, although all patients experienced some mild form of toxicity, mostly gastrointestinal symptoms, neurotoxicity and haematotoxicity. Grade 3-4 adverse effects were noted in 39% of the patients. No toxic deaths occurred. It can be concluded that the present regimen produces meaningful responses for patients with metastatic melanoma. A randomised study is needed to determine the effect on survival.

Experience with interferon alpha 2b combined with dacarbazine in the treatment of metastatic malignant melanoma

A prospectively randomized trial was undertaken to compare dacarbazine (DTIC) alone with DTIC plus interferon in patients with metastatic malignant melanoma. Of the 73 patients who entered on the study, 36 were randomized to receive DTIC alone and 37 were randomized to receive the combination DTIC plus interferon. The two sections were well balanced. There was more toxicity on the combination section, but no life threatening toxicity. The overall response rate for patients on DTIC was 20% (two complete and five partial responses) (95% CI 7-39%) and for patients on DTIC plus interferon was 50% (13 complete and four partial responses) (95% CI 26-72%) (p = 0.007). The median time to treatment failure, was significantly more in favour of the combination treatment (9 versus 2.5 months; p < 0.01, Mantel-Cox). The median survival of 16.7 versus 8 months was in favor of the combination treatment (p < 0.01). The reasons for the improved results with the combination treatment are discussed. The Eastern Cooperative Oncology Group is currently, based on the results of this study, investigating the role of interferon combinations in metastatic malignant melanoma.

Antiphospholipid syndrome associated with immunotherapy for patients with melanoma

BACKGROUND

Immunotherapy for patients with cancer is associated with severe side effects, including the possible induction of autoantibodies. The latter was proven for antithyroid microsomal and antithyroglobulin antibodies.

METHODS

This study was designed to evaluate antiphospholipid antibodies (APA) in 30 patients receiving three different forms of immunotherapy for disseminated melanoma using interleukin-2 (IL-2), alpha-interferon (alpha-interferon) or the combination of both.

RESULTS

APA were detected in none of 18 patients treated with IL-2 alone, 2 of 4 (50%) treated with alpha-interferon alone, and 3 of 8 (37.5%) treated with the combination of both. In the last group, increased concentrations of APA were observed, while the patients were still receiving alpha-interferon alone. APA levels were not detected in any of 10 patients with melanoma who were not treated with alpha-interferon or IL-2. In patients with increased APA, five of five (100%) had a prolongation of the partial thromboplastin time and 4 or five (80%) had deep venous thrombosis, which in one patient was followed by pulmonary embolism.

CONCLUSIONS

The high incidence of therapy-induced elevated APA concentrations suggests that these should be carefully monitored in all patients receiving immunotherapy with alpha-interferon.

Recombinant interferon alpha-2a in combination with dacarbazine in the treatment of metastatic malignant melanoma: analysis of long-term responding patients

Thirty-four evaluable patients with metastatic malignant melanoma were entered into a phase-II study designed to assess the response rate and analyze the long-term therapeutic efficacy of recombinant interferon (rIFN) alpha-2a and dacarbazine. Patients received 14 days of daily subcutaneous r-IFN alpha-2a (3 x 10(6) IU/day), followed by 9 x 10(6) IU on alternate days, as long as objective response lasted, in combination with i.v. dacarbazine started on day 7 (400 mg/m2) and repeated every 21 days (dacarbazine doses were escalated to 800 mg/m2). In 11 patients, 6 complete (17.6%) and 5 partial (14.7%) responses were seen, with an overall response rate of 32.3% (95% confidence interval: 16%-48%). The median survival time of the responding patients was significantly better than that of patients with progressive disease (P = 0.01) and the median response time of the patients showing complete response was longer than that of the partially responding patients (14 and 7 months respectively, P = 0.06).

Interferon alpha 2a and vindesine in the treatment of advanced malignant melanoma

21 patients with advanced malignant melanoma were treated with interferon alpha 2a at 9MU daily with vindesine every 21 days. No patient had received previous chemotherapy. The overall response rate was 24% with a median survival time of 33 months in 18 patients. The four complete remissions were maintained for 20, 18, 15 and 11 months, while the single partial remission continues at 18 months after the start of treatment. Side-effects were generally mild or moderate and did not lead to cessation of therapy. This combination provides an active outpatient regimen for advanced melanoma and produces durable remissions.

Role of interferons in the therapy of melanoma

A range of potent immunoregulatory molecules termed cytokines has become available for the therapy of human melanoma. Among the cytokines, the interferons (IFN) have been examined in great depth for the therapy of melanoma. IFN are able to modulate host effector cell function, including the tumor cytolytic function of lymphocytes and monocytes. IFN also have the capacity to regulate the distribution of circulating immunoregulatory (T) lymphocytes and the expression of tumor cell surface antigens, as well as class I and II products of the major histocompatibility locus. These activities of the IFN have led to their early application for treatment of human melanoma. The empirical evidence that IFN alpha exerts clinically significant anti-tumor effects against melanoma is reviewed, and evolving status of adjuvant trials of IFN alpha and gamma is noted. New indirect host-mediated anti-tumor activities that may potentially be manifest by IFN have yet to be fully harnessed. The opportunity to obtain meaningful anti-tumor activity in advanced disease or adjuvant settings, at dose ranges below those which are toxic (conventional maximal tolerable), are at hand. The U.S. cooperative groups [Eastern Cooperative Oncology Group (ECOG), Cancer and Leukemia Group B (CALGB), and South West Oncology Group (SWOG)] are studying IFN gamma in pursuit of this goal in advanced and adjuvant settings for melanoma and other tumors. The determination of the clinical role of IFN as biologic response modifiers demands equal commitment to the clinical assessment of immunobiologic mechanisms and anti-tumor effects. The immunologic assessment of IFN and a number of other cytokines is a major focus of the Pittsburgh Cancer Institute. Regional delivery of cytokines such as interleukin-2 (IL-2) may be the most appropriate and least toxic approach, given their half-life. Regional therapy by the intralesional route has yielded enhanced activity for a range of biologics, including bacillus Calmette-Guerin (BCG), IL-2, and tumor necrosis factor (TNF). Intralymphatic therapy with methanol extraction residue of BCG (MER-BCG) has been tested, and trials are now in progress with IL-2 to assess the optimal dosage by this route. It is likely that the optimal role of IFN and other cytokines will be found in combination with one another, and with different biologic modalities such as monoclonal antibodies and vaccines, to allow expansion and heightened activity of the desired effector cell populations in the host. Enhanced host toxicities, as well as anti-tumor effects, may require that special attention be devoted to optimal sequence of administration to enhance the therapeutic index.

Clinical use of biologic response modifiers in cancer treatment: an overview. Part I. The interferons

Interferons are proteins with antiviral, antiproliferative, and immune-regulating activity. They are classified as alfa, beta, or gamma on the basis of antigenicity and biologic properties. Alfa interferons as single-agent therapy produce clinical improvement in approximately 90 percent of patients with hairy-cell leukemia, and up to 70 percent of patients with chronic myelogenous leukemia (CML) in early-stage disease. Prolonged suppression or elimination of the leukemic cell clone by interferon may ultimately increase survival of patients with CML. Interferon is not effective single-agent therapy for multiple myeloma, but improves response rate when combined with conventional agents. AIDS-associated Kaposi's sarcoma demonstrates a 40 percent objective response rate to interferon, with less risk of immune system suppression than conventional cytotoxics. Other applications of alfa interferon include malignant melanoma and renal cell carcinoma. Beta interferon is similar to the alfa subtype and may have utility in treatment of brain tumors. Gamma interferon is an important immune regulator with qualitative and quantitative differences in its efficacy and toxicity when compared with alfa interferon.

Interferons: biological and clinical effects

Interferons play a key role in the immune system as biological response modifiers. Interferons alpha, beta, and gamma have been characterized, their nucleotide sequences defined, and the proteins produced by recombinant DNA technology. The myriad actions of interferons include enhancement of natural killer cell activity and antigen expression, induction of varied proteins, activation of macrophages, and antiviral, antiproliferative and antitumor effects. Clinical trials have demonstrated efficacy of interferons in some malignancies and ongoing studies are investigating results of combinations with other biological response modifiers and cytotoxic agents.

Nonsurgical treatments for skin cancer: retinoids and alpha-interferon

Retinoids, the natural and synthetic analogs of vitamin A, and alpha-interferon have been used effectively in the treatment of certain cutaneous premalignancies and malignancies. Retinoids have shown impressive activity against premalignant disorders of the skin (actinic keratoses, keratoacanthoma, epidermodysplasia verruciformis) and of other epithelial sites (oral leukoplakia, cervical dysplasia). In established basal cell skin cancers, topical retinoid treatment has produced a complete response rate of 33%, and systemic retinoids have produced an objective response rate of 51%. In advanced squamous cell skin cancers, systemic retinoids have produced a response rate of over 70%. Intralesional alpha-interferon has produced impressive responses and systemic alpha-interferon has produced a 50% objective response rate in basal and squamous cell carcinoma. Retinoid therapy and alpha-interferon have produced modest overall results in melanoma, although striking individual responses have been reported. In cutaneous T-cell lymphoma, which is notably refractory to chemotherapy, retinoids and alpha-interferon have produced responses in 60%+ and 70%+ of cases, respectively. Retinoids and alpha-interferon, either alone or in combination, offer exciting prospects for primary and neoadjuvant therapy for advanced malignancy. Retinoids also show promise as relatively nontoxic preventive and adjuvant therapy. Researchers should focus on integrating these drugs with other biological response modifiers, differentiation agents, and cytotoxic drugs for treating advanced malignancy.