Interferon-alpha and chemohormonal therapy for patients with advanced melanoma: final results of a phase I-II study of the Cancer Biotherapy Research Group and the Mid-Atlantic Oncology Program

Direct and indirect effects of IFN-α2b in malignancy treatment: not only an archer but also an arrow

Interferon-α2b (IFN-α2b) is a highly active cytokine that belongs to the interferon-α (IFN-α) family. IFN-α2b has beneficial antiviral, antitumour, antiparasitic and immunomodulatory activities. Direct and indirect antiproliferative effects of IFN-α2b have been found to occur via multiple pathways, mainly the JAK-STAT pathway, in certain cancers. This article reviews mechanistic studies and clinical trials on IFN-α2b. Potential regulators of the function of IFN-α2b were also reviewed, which could be utilized to relieve the poor response to IFN-α2b. IFN-α2b can function not only by enhancing the systematic immune response but also by directly killing tumour cells. Different parts of JAK-STAT pathway activated by IFN-α2b, such as interferon alpha and beta receptors (IFNARs), Janus kinases (JAKs) and IFN‐stimulated gene factor 3 (ISGF3), might serve as potential target for enhancing the pharmacological action of IFN-α2b. Despite some issues that remain to be solved, based on current evidence, IFN-α2b can inhibit disease progression and improve the survival of patients with certain types of malignant tumours. More efforts should be made to address potential adverse effects and complications.

Efficacy of Antiviral Drugs against Feline Immunodeficiency Virus

Feline immunodeficiency virus (FIV) is one of the most common infectious agents affecting cats worldwide .FIV and human immunodeficiency virus (HIV) share many properties: both are lifelong persistent lentiviruses that are similar genetically and morphologically and both viruses propagate in T-lymphocytes, macrophages, and neural cells. Experimentally infected cats have measurable immune suppression, which sometimes progresses to an acquired immunodeficiency syndrome. A transient initial state of infection is followed by a long latent stage with low virus replication and absence of clinical signs. In the terminal stage, both viruses can cause severe immunosuppression. Thus, FIV infection in cats has become an important natural model for studying HIV infection in humans, especially for evaluation of antiviral compounds. Of particular importance for chemotherapeutic studies is the close similarity between the reverse transcriptase (RT) of FIV and HIV, which results in high in vitro susceptibility of FIV to many RT-targeted antiviral compounds used in the treatment of HIV-infected patients. Thus, the aim of this article is to provide an up-to-date review of studies on antiviral treatment of FIV, focusing on commercially available compounds for human or animal use.

Efficacy of antiviral chemotherapy for retrovirus-infected cats: What does the current literature tell us?

GLOBAL IMPORTANCE

The two feline retroviruses, feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV), are global and widespread, but differ in their potential to cause disease.

VIRAL INFECTION - FIV

FIV, a lentivirus that shares many properties with human immunodeficiency virus (HIV), can cause an acquired immune deficiency syndrome, which predisposes cats to other infections, stomatitis, neurological disorders and tumours. Although secondary infections are common, specific opportunistic infections or acquired immunodeficiency virus-defining infections, such as those that occur with HIV, are not commonly reported in FIV-infected cats. In most naturally infected cats, FIV does not cause a severe clinical syndrome; with appropriate care, FIV-infected cats can live many years before succumbing to conditions unrelated to their FIV infection. Thus, overall survival time is not necessarily shorter than in uninfected cats, and quality of life is usually high over many years or lifelong.

VIRAL INFECTION - FELV

FeLV, an oncornavirus, is more pathogenic than FIV. Historically, it was considered to account for more disease-related deaths and clinical syndromes in cats than any other infectious agent. Recently, the prevalence and importance of FeLV have been decreasing, mainly because of testing and eradication programmes and the use of FeLV vaccines. Progressive FeLV infection can cause tumours, bone marrow suppression and immunosuppression, as well as neurological and other disorders, and leads to a decrease in life expectancy. However, with appropriate care, many FeLV-infected cats can also live several years with a good quality of life.

PRACTICAL RELEVANCE

A decision regarding treatment or euthanasia should never be based solely on the presence or absence of a retrovirus infection. Antiviral chemotherapy is of increasing interest in veterinary medicine, but is still not used commonly.

EVIDENCE BASE

This article reviews the current literature on antiviral chemotherapy in retrovirus-infected cats, focusing on drugs that are currently available on the market and, thus, could potentially be used in cats.

IFN signaling: how a non-canonical model led to the development of IFN mimetics

The classical model of cytokine signaling dominates our view of specific gene activation by cytokines such as the interferons (IFNs). The importance of the model extends beyond cytokines and applies to hormones such as growth hormone (GH) and insulin, and growth factors such as epidermal growth factor (EGF) and fibroblast growth factor (FGF). According to this model, ligand activates the cell via interaction with the extracellular domain of the receptor. This results in activation of receptor or receptor-associated tyrosine kinases, primarily of the Janus activated kinase (JAK) family, phosphorylation and dimerization of the signal transducer and activator of transcription (STAT) transcription factors, which dissociate from the receptor cytoplasmic domain and translocate to the nucleus. This view ascribes no further role to the ligand, JAK kinase, or receptor in either specific gene activation or the associated epigenetic events. The presence of dimeric STATs in the nucleus essentially explains it all. Our studies have resulted in the development of a non-canonical, more complex model of IFNγ signaling that is akin to that of steroid hormone (SH)/steroid receptor (SR) signaling. We have shown that ligand, receptor, activated JAKs, and STATs are associated with specific gene activation, where the receptor subunit IFNGR1 functions as a co-transcription factor and the JAKs are involved in associated epigenetic events. We found that the type I IFN system functions similarly. The fact that GH receptor, insulin receptor, EGF receptor, and FGF receptor undergo nuclear translocation upon ligand binding suggests that they may also function similarly. The SH/SR nature of type I and II IFN signaling provides insight into the specificity of signaling by members of cytokine families. The non-canonical model could also provide better understanding to more complex cytokine families such as those of IL-2 and IL-12, whose members often use the same JAKs and STATs, but also have different functions and properties.

Anticarcinogenic impact of interferon therapy on the progression of hepatocellular carcinoma in patients with chronic viral infection

Hepatocellular carcinoma (HCC) is mainly caused by a persistent infection due to the hepatitis B or hepatitis C virus. The number of HCC cases is increasing in Asian and African countries, as well as in European and American countries. Interferon (IFN) therapy, used for type B chronic liver diseases, inhibits hepatic carcinogenesis in patients with compensated cirrhosis. However, there is insufficient evidence that IFN therapy inhibits hepatic carcinogenesis in patients with chronic hepatitis B. There are few cases of HCC due to chronic hepatitis B, and long-term follow-up periods verifying the inhibitory effect of IFN on hepatic carcinogenesis have not been obtained. To improve the prognosis of type B chronic liver diseases, it is important that hepatitis treatment follows guidelines in which a patient's age and the extent of hepatic fibrosis are taken into account. As for chronic hepatitis C, since a sustained virological response (SVR) in IFN therapy inhibits hepatic carcinogenesis and improves prognosis, treatment that aims for an SVR while taking into consideration host-sided and virus-sided factors is recommended for patients with type C chronic liver diseases. In areas with low incidence of HCC (e.g. USA), a large number of cases and a long-term follow-up period are needed before it can be accepted that IFN therapy inhibits hepatic carcinogenesis. After locally curative treatment of HCC, IFN therapy suppresses recurrence and improves survival rates.

Cancer immunotherapy

Cancer immunotherapy consists of approaches that modify the host immune system, and/or the utilization of components of the immune system, as cancer treatment. During the past 25 years, 17 immunologic products have received regulatory approval based on anticancer activity as single agents and/or in combination with chemotherapy. These include the nonspecific immune stimulants BCG and levamisole; the cytokines interferon-α and interleukin-2; the monoclonal antibodies rituximab, ofatumumab, alemtuzumab, trastuzumab, bevacizumab, cetuximab, and panitumumab; the radiolabeled antibodies Y-90 ibritumomab tiuxetan and I-131 tositumomab; the immunotoxins denileukin diftitox and gemtuzumab ozogamicin; nonmyeloablative allogeneic transplants with donor lymphocyte infusions; and the anti-prostate cancer cell-based therapy sipuleucel-T. All but two of these products are still regularly used to treat various B- and T-cell malignancies, and numerous solid tumors, including breast, lung, colorectal, prostate, melanoma, kidney, glioblastoma, bladder, and head and neck. Positive randomized trials have recently been reported for idiotype vaccines in lymphoma and a peptide vaccine in melanoma. The anti-CTLA-4 monoclonal antibody ipilumumab, which blocks regulatory T-cells, is expected to receive regulatory approval in the near future, based on a randomized trial in melanoma. As the fourth modality of cancer treatment, biotherapy/immunotherapy is an increasingly important component of the anticancer armamentarium.

Construction and expression of a novel bioactive IFN-alpha2b/CM4 fusion protein in Escherichia coli

Human interferon alpha2b (IFN-alpha2b) is a pleiotropic cytokine used for the treatment of various cancers. Antibacterial peptide CM4 is a small peptide that can strongly inhibit many kinds of bacteria, fungi, and tumor cells, but it does no harm to normal cells. Here, we describe a protein expression system for the production of IFN-alpha2b/CM4 fusion protein in insoluble form in Escherichia coli, coupled to an efficient dialysis refolding and histidine-tag purification protocol. The expressed IFN-alpha2b/CM4 fusion protein not only displays significantly improved antitumor activity, but also retains the antibacterial-antifungal activity of CM4.

Growth inhibitory effects of IFN-beta on human liver cancer cells in vitro and in vivo

We investigated the effects of interferon-beta (IFN-beta) on the growth of human liver cancer cells. The effects of IFN-beta with or without 5-fluorouracil (5-FU) on the proliferation of 13 liver cancer cell lines were investigated in vitro. Chronologic change in IFN-alpha receptor 2 (IFNAR-2) expression was monitored in hepatocellular carcinoma (HCC) cells (HAK-1B) cultured with IFN-beta. After HAK-1B cells were transplanted into nude mice, various doses of IFN-beta were administered, and the tumor volume, weight, histology, tumor blood vessel, and angiogenesis factor expression were examined. IFN-beta inhibited the growth of 11 cell lines with apoptosis in a dose-dependent and time-dependent manner. With IFN-beta, IFNAR-2 expression in HAK-1B cells was significantly downregulated from 6 to 12 h. IFN-beta induced a dose-dependent decrease in tumor volume and weight and a significant increase of apoptosis in the tumor. Both basic fibroblast growth factor (bFGF) and blood vessel number in the tumor decreased only in mice receiving the lowest dose (1000 IU) of IFN-beta. IFN-beta with 10 muM of 5-FU frequently induced synergistic antiproliferative effects. IFN-beta with or without 5-FU induces strong antitumor effects in HCC cells, and we conclude that IFN-beta is useful for the prevention and treatment of HCC.

Overexpression of a synthetic gene encoding human alpha interferon in Escherichia coli

Interferons (IFNs) represent an important defense mechanism in vertebrates. In this work, we describe gene synthesis and assembly using the polymerase chain reaction as a method for single-step synthesis of DNA sequences. The oligonucleotides designed were based on Escherichia coli codon usage and two genes of IFN were synthesized: one containing a DNA sequence already known and the other, a mutated form in which two cysteine amino acid residues were replaced by serines in an attempt to improve the stability of the protein. DNA sequences were cloned into pAE, an E. coli vector that allows heterologous protein expression with or without a histidine tag. Recombinant human interferons (rhIFNs) were identified by Western blotting and ELISA using anti-human interferon polyclonal antibodies. Purification of the recombinant His-tagged proteins was achieved in a single step by Ni(2+)-charged column chromatography while proteins without His-tag were purified by extensively washing the inclusion bodies, the final yields being approximately 210 and 75mg/L, respectively. The rhIFNs expressed within this system were biologically active ( approximately 1,1x10(8)IU/mg) based on antiviral assay. The combined methodologies described here proved to be cost-effective and could be extended to other genes/proteins of interest.

Re-evaluating the role of dacarbazine in metastatic melanoma: what have we learned in 30 years?

Since dacarbazine was approved for treating metastatic melanoma in the 1970s, numerous studies have evaluated whether different schedules and dacarbazine-based combinations improve clinical outcomes. This evidence-based review shows that combining dacarbazine with other drugs having single-agent activity and/or hormonal or immunotherapeutic compounds fails to provide clinically meaningful improvements in survival, and may increase toxicity. In patients with metastatic melanoma, dacarbazine was previously administered in cycles of multiple consecutive daily infusions per cycle. The introduction of potent antiemetics, together with concerns relating to patient comfort and clinic utilisation time, has enabled regimens involving single-dose dacarbazine, administered at the same total dose per cycle. These appear to be as effective as multiple-dose schedules, are well tolerated, and are more straightforward to administer. Single-administration dacarbazine (850-1000 mg/m2), once every 3 weeks, is currently the standard reference therapy in patients with advanced melanoma. New effective therapies are urgently needed for this treatment-refractory disease.

Chemoimmunohormonal therapy with carmustine, dacarbazine, cisplatin, tamoxifen, and interferon for metastatic melanoma: a prospective phase II study

The objective of this study was to investigate the efficacy of our treatment regimen in metastatic melanoma. Thirty patients entered the study after undergoing a thorough metastatic workup. Treatment protocol included carmustine (BCNU) (150 mg/m(2) IV, day 1) every 6 weeks, dacarbazine (DTIC) (220 mg/m(2) IV, days 1-3), and cisplatin (25 mg/m(2) IV, days 1-3) every 3 weeks, interferon A-2B (6 x 10(6) U/m daily s.c. on days 4-8 and 16-20) and tamoxifen 20 mg/day for 6 weeks. Among 29 evaluable patients, overall response was seen in 15 (52%) and complete response in 5 (17%) patients. Median duration of partial response was 4 months (range, 1-12 months); of complete response was 8 months (range, 2-14 months). Complete response continues in two patients with lung metastases. Median survival time was 8.7 months. Side effects were tolerable. Four (13%) patients developed neutropenic fever, and platelet transfusions were required in five (17%) patients. One patient died of neutropenic sepsis. Thrombocytopenia caused prolongation of the median interval between the first and second courses, and drug doses were reduced in the second course in 8 of 26 (31%) patients. Our chemoimmunohormonal regimen is efficient in metastatic malignant melanoma and can induce durable remission. Severe thrombocytopenia leads to a reduction of carmustine dose in a new protocol.

Metastatic melanoma: chemotherapy

The incidence of cutaneous melanoma has been rapidly increasing, with an estimate of 47,700 new cases diagnosed in 2000 in the United States. In the early phase of its natural history, melanoma is cured in most cases by surgery, but once the metastatic phase develops, it is almost always fatal. The treatment of metastatic melanoma remains unsatisfactory. Systemic therapy has not been successful up to now, with very low response rates to single-agent chemotherapy. Polychemotherapy has increased the response rate (RR), without a significant improvement in overall survival. Immunotherapy alone is able to induce only a few durable complete responses (CRs). New chemotherapeutic and biologic agents are now available and promising combined approaches targeting the tumor by several different mechanisms are desirable and will probably represent the future modality of treatment.

Combination chemotherapy with or without s.c. IL-2 and IFN-alpha: results of a prospectively randomized trial of the Cooperative Advanced Malignant Melanoma Chemoimmunotherapy Group (ACIMM)

The purpose of this randomized trial was to evaluate the efficacy of combination chemoimmunotherapy compared with chemotherapy alone. A total of 124 patients were randomized to receive intravenous cisplatin (35 mg m(-2), days 1-3), carmustine (150 mg m(-2), day 1, cycles 1 and 3 only), dacarbacine (220 mg m(-2), days 1-3) and oral tamoxifen (20 mg m(-2), daily) in combination with (n=64) or without (n=60) sequential subcutaneous IL-2 and IFN-alpha. In those patients who received sequential immunotherapy, each cycle of chemotherapy was followed by outpatient s.c. IL-2 (10 x 10(6) IU m(-2), days 3-5, week 4; 5 x 10(6) IU m(-2), days 1, 3, 5, week 5) and s.c. IFN-alpha (5 x 10(6) IU m(-2), day 1, week 4; days 1, 3, 5, week 5). The overall response rate of patients treated with the combination of chemotherapy and IL-2/IFN-alpha was 34.3% with seven complete responses (10.9%) and 15 partial responses (23.4%). In patients treated with chemotherapy, only, the overall response rate was 29.9% with eight complete responses (13.3%) and 10 partial responses (16.6%). There was no significant difference in median progression free survival (0 months vs 4 months) and in median overall survival (12 months vs 13 months) for combined chemoimmunotherapy and for chemotherapy, respectively.

Analysis of gene expression using high-density and IFN-gamma-specific low-density cDNA arrays

The combination of high and low density cDNA filter array technology potentially permits both the identification of subsets of induced genes and convenient and rapid multisample expression profiling of such subsets under a variety of conditions. The JAK/STAT1 pathway for IFN-gamma signaling in human cells has been well characterized, but the extent and importance of additional pathways remain to be established. Here, using high-density filter arrays of the RZPD UniGene set, we identified 18 novel IFN-gamma-inducible genes. Expression profiling was carried out using low-density arrays representing both novel and known IFN-gamma-inducible genes. Initial experiments failed to detect evidence for any novel non-JAK-dependent pathways in cells expressing a kinase-dead JAK2. The data, however, validated the potential of the combined methods in establishing rapid and convenient expression profiling of several hundred genes in response to any ligand of choice.

Short-term autologous tumor cell lines for the active specific immunotherapy of patients with metastatic melanoma

We established short-term cell lines for 108/170 (64%) patients with metastatic melanoma. Tumor cell numbers were expanded to 10(8), then cells were irradiated, aliquoted, and cryopreserved for clinical use. Vaccines have been used to treat 69 patients with clinical follow up for 33 who had measurable metastatic disease at the time vaccine therapy was initiated (METS), and 33 who had no evidence of disease (NED) at the time of vaccine therapy following surgical resection of metastases. The protocol called for a baseline test of delayed tumor hypersensitivity (DTH), three weekly injections, a repeat of the DTH test, then monthly injections for an additional 5 months. Objective tumor responses were noted in 3/26 (12%) patients who received a minimum of three vaccinations, one complete, and two partial, with survivals of 36, 46+, and 78+ months. Only 6/64 (9.4%) had a positive DTH (>10 mm) at baseline, including three METS, all of whom progressed within 4 months and died within a year, and three who are still NED after more than 5 years. Conversion of DTH from negative to positive was documented in 18/44 (41%) patients who were tested at week 0 and 4. At a median follow up of greater than 5 years, the median overall survival (OS) was 40 months for "NED" with a 5-year survival rate of 39%, and 8.6 months with a 5-year survival rate of 10% for "METS" The 18 patients who had conversion of their DTH had a median event-free survival (EFS) of 15.8 months and 5-year EFS of 32% compared to 4.2 months and 9% for the 26 non-converters (P=0.012, two-tailed, log-rank test). Among patients who were NED when treatment started, the 12 patients whose DTH converted had a median overall survival of 61.4 months with 5-year survival of 63% compared to 9.7 months and 0% for the 13 non-converters (P=0.0026). This treatment approach is feasible, produces minimal toxicity, and is associated with long-term survival in a significant subset of patients.

A phase II trial of recombinant interferon alpha-2b and cisplatin in metastatic melanoma

In this phase II study 37 patients with metastatic melanoma were treated with cisplatin 100 mg/m2 every three weeks and interferon alpha-2b 10 MU subcutaneously three times weekly; 125 cycles were administered. Thirty-four patients were evaluable for response and all 37 patients were assessable for toxicity. Four patients stopped treatment with cisplatin because of severe nephrotoxicity, and six patients stopped therapy because of other toxicities. Response rate was 6/34 = 18% (95%) CI (confidence interval): 7%-35%). One patient reached complete response lasting 27+ months. Five patients obtained partial responses with a median duration of response of 7 months (range 5-15+ ). Median time to progression was 2.3 months (range 1-27+). Median survival was 5 months (range 1-27+). We conclude that the combination of high-dose cisplatin 100 mg/m2 and interferon alpha-2b is associated with unacceptable toxicity. Haematological toxicity and nephrotoxicity were pronounced and the response rate was meagre and not encouraging.

Phase II trial of subcutaneous interleukin-2, subcutaneous interferon-alpha, intravenous combination chemotherapy, and oral tamoxifen in the treatment of metastatic melanoma: final results of cancer biotherapy research group 94-11

BACKGROUND

The treatment of metastatic melanoma remains unsatisfactory despite encouraging results with biotherapy and combination chemotherapy. Combining these two modalities may improve outcomes for such patients.

METHODS

Eligible patients had metastatic melanoma, were in good medical condition, and had not been treated previously for metastatic disease. A 42-day treatment cycle consisted of: tamoxifen 10 mg p.o. b.i.d. days 1-42, carmustine 150 mg/m2 i.v. on day three, dacarbazine 220 mg/m2 and cisplatin 25 mg/m2 i.v. q.d. days 3-5, and 24-26, interferon-alpha 2b 6.0 MU/m2 s.c. days 8-12 and 29-33, and interleukin-2 11 MU/m2 s.c. days 8, 10, 12 and 29, 31, 33. In the absence of tumor progression, patients could receive up to six cycles of alternating treatment. Toxicity and tumor response was assessed following each treatment cycle; survival was determined from the first date of treatment.

RESULTS

The 28 melanoma patients included 21 men and 7 women, with a median age of 55 years with a range of 26-77. Fifty-four percent were asymptomatic when treatment was initiated. Eighty percent had soft tissue metastases, 32% lung, 28% liver, and 8% bone. There were nine patients with significant tumor responses (three complete, six partial) for a response rate of 32% (18-57% 95% CI) based on intent-to-treat analysis, and 38% (18-57%, 95% CI) for the 24 patients who were evaluable for response. The months of duration of survival for responders were 38.9+, 27.2+, 22.8+, 16.3, 13.2, 9.4, 7.5, 6.5+, and 5.8. At a median follow-up of 31 months, the median duration of event-free survival was 4.6 months; median survival was 9.4 months. The survival rate one year from initiating treatment was 42%; 2-year survival was 14%. The most frequent toxicities were 96% nausea/vomiting, 80% fatigue, 73% thrombocytopenia, 60% neutropenia, and 44% fever. Two patients experienced early death that may have been treatment related; one died of cardiovascular complications and the other of a central nervous system event.

CONCLUSION

This outpatient regimen was associated with significant toxicity including a 7% rate of possible treatment-related death. Tumor regression rates and survival were similar to results reported for chemotherapy alone, or inpatient IL-2-based therapy, but did not suggest an improvement in outcome.

[Managing cutaneous melanoma]

Cutaneous melanoma represents the main cause of death among skin cancers. Early diagnosis gives, for the time being, the only possibility for high rate of curative treatment. Diagnosis is based on pathological findings, and at primary tumor stage. Breslow thickness of the lesion is the best prognostic index. At local stage of the disease, treatment is precisely codified by international recommendations and consensus conferences. Follow-up after surgical treatment is also well codified. Treatment of lymph node invasion or metastatic disease is, on the other hand, less codified. Despite recent advances, especially in immunotherapy, treatment of advanced stages of melanoma remains difficult.