Phase II trial of branched peginterferon-alpha 2a (40 kDa) for patients with advanced renal cell carcinoma

Real-world study of pegylated interferon α-2a to treat mycosis fungoides/Sézary syndrome using time to next treatment as a measure of clinical benefit: an EORTC CLTG study

BACKGROUND

Mycosis fungoides (MF) and Sézary syndrome (SS) are chronic malignant diseases that typically necessitate diverse strategies to achieve remission. Systemic interferon (IFN)-α (subtypes 2a and 2b) has been used to treat MF/SS since 1984; however, its production was recently stopped. The recombinant pegylated (PEG) form of IFN-α-2a remains the only alternative IFN treatment, although it has not been approved for use in MF/SS.

OBJECTIVES

To assess the effectiveness and safety of PEG-IFN-α-2a in monotherapy and in combination with other treatments using time to next treatment (TTNT) as a measure of clinical therapeutic benefit in a real-world setting.

METHODS

We conducted an international, multicentre retrospective study of patients with MF and SS (of any stage) treated with PEG-IFN-α-2a from July 2012 to February 2022. Patients were included across 11 centres in 10 countries. The primary endpoints were to determine the TTNT of PEG-IFN-α-2a and adverse events (AEs) in MF/SS.

RESULTS

In total, 105 patients were included [mean (SD) age 61 (13.1) years]; 42 (40.0%) had stage IA-IIA and 63 (60.0%) had stage IIB-IVB disease. PEG-IFN-α-2a was combined with other therapies in 67 (63.8%) patients, most commonly with extracorporeal photopheresis (36%) and bexarotene (22%). Patients with stage I-IIA disease achieved an overall response rate (ORR) of 57%; the ORR in those with stage IIB-IVB disease was 51%. Combination treatment resulted in a median TTNT of 10.4 months (range 0.6-50.7) vs. 7.0 months (range 0.7-52.4) for those who received monotherapy (P < 0.01). Overall, the mean (SD) TTNT was 9.2 (10.6) months and the ORR was 53.3% (n = 56). A complete response was seen in 13% of patients and a partial response in 40%. AEs were described in 68.6% (n = 72) of patients. Flu-like symptoms (n = 28; 26.7%), lymphopenia (n = 24; 22.9%) and elevated liver function (n = 10; 9.5%) were the most frequently reported. Grade 3-4 AEs were reported in 23 (21.9%) patients, mostly related to myelosuppression.

CONCLUSIONS

PEG-IFN-α-2a for MF/SS resulted in an ORR of 53.3% and a mean (SD) TTNT of 9.2 (10.6) months. Combination regimens were superior to monotherapy and doses of 180 µg PEG-IFN-α-2a weekly were related to a higher ORR.

Interferon-beta enhances sensitivity to gemcitabine in pancreatic cancer

Background

Adjuvant gemcitabine for pancreatic cancer has limited efficacy in the clinical setting. Impaired drug metabolism is associated with treatment resistance. We aimed to evaluate the chemosensitising effect of interferon-beta (IFN-β).

Methods

BxPC-3, CFPAC-1, and Panc-1 cells were pre-treated with IFN-β followed by gemcitabine monotherapy. The effect on cell growth, colony formation, and cell cycle was determined. RT-qPCR was used to measure gene expression. BxPC-3 cells were used in a heterotopic subcutaneous mouse model.

Results

IFN-β increased sensitivity to gemcitabine (4-, 7.7-, and 1.7-fold EC₅₀ decrease in BxPC-3, CFPAC-1, and Panc-1, respectively; all P < 0.001). Findings were confirmed when assessing colony formation. The percentage of cells in the S-phase was significantly increased after IFN-β treatment only in BxPC-3 and CFPAC-1 by 12 and 7%, respectively (p < 0.001 and p < 0.05, respectively). Thereby, IFN-β upregulated expression of the drug transporters SLC28A1 in BxPC-3 (252%) and SLC28A3 in BxPC-3 (127%) and CFPAC-1 (223%) (all p < 0.001). In vivo, combination therapy reduced tumor volume with 45% (P = 0.01). Both ex vivo and in vivo data demonstrate a significant reduction in the number of proliferating cells, whereas apoptosis was increased.

Conclusions

For the first time, we validated the chemosensitising effects of IFN-β when combined with gemcitabine in vitro, ex vivo, and in vivo. This was driven by cell cycle modulation and associated with an upregulation of genes involving intracellular uptake of gemcitabine. The use of IFN-β in combination with gemcitabine seems promising in patients with pancreatic cancer and needs to be further explored.

Dose-escalation study evaluating pegylated interferon alpha-2a in patients with cutaneous T-cell lymphoma

BACKGROUND

This open-label, multicenter, dose-escalation study evaluated the safety, tolerability, and efficacy of subcutaneous pegylated (40 kD) interferon α-2a (PEG-IFN α-2a) in patients with cutaneous T-cell lymphoma (CTCL).

PATIENTS AND METHODS

PEG-IFN α-2a was administered subcutaneously at 180 (n = 4), 270 (n = 6), or 360 μg (n = 3) once weekly for 12 weeks. Efficacy was assessed by the proportion of patients with complete response (CR) or partial response (PR).

RESULTS

PEG-IFN α-2a was generally well tolerated, with a moderate number of reductions or withholding of doses because of adverse events (AEs) (25% (n = 1), 66% (n = 4), and 0% (n = 0) in the 180-, 270-, and 360-μg/week groups, respectively). The only dose-limiting toxicity was a grade 3 elevation of liver enzymes in the 270-μg dose group. The most common AEs were fatigue, acute flu-like symptoms, and hepatic toxicity. The major response rate (CR or PR) was 50% in the 180-μg group (CR, 50%; PR, 0%), 83% in the 270-μg group (CR, 67%; PR, 17%), and 66% in the 360-μg group (CR, 33%; PR, 33%).

CONCLUSION

PEG-IFN α-2a at doses up to 360 μg once weekly was well tolerated in patients with CTCL up to the highest dose group and showed good response rates. Due to their good tolerance even in high doses, they might be an option for patients not tolerating standard IFN-α preparations. However, for this purpose and to evaluate comparability between standard and PEG-IFN larger clinical trials are needed, alone and in combination with oral photochemotherapy (PUVA).

Systemic Therapy in Metastatic Renal Cell Carcinoma

During the last two decades considerable advances have been made in the understanding of the biology of RCC. Although the best therapeutic options for patients with metastatic RCC have not been defined, it is apparent that use of immunomodulating cytokines like interferon-alpha and interleukin-2 either alone or combined with chemotherapeutic agents provides the best available results in routine clinical practice. Numerous studies have confirmed that objective tumour responses are seen only in a small fraction of patients (averagely in 15–20%). In spite of a lot of evidence that these treatments prolong survival, expectations of only 5–10% long-term survivals with complete and durable regression of tumours are realistic. Recently, some new promising investigational approaches have been reported. These may already in near future further improve overall treatment results.

Potentials of interferon therapy in the treatment of pancreatic cancer

Pancreatic cancer is a highly aggressive malignancy with limited treatment options. To improve survival for patients with pancreatic cancer, research has focused on other treatment modalities like adding biological modulators such as type-I interferons (IFNs). Type I IFNs (ie, IFN-α/IFN-β) have antiproliferative, antiviral, and immunoregulatory activities. Furthermore, they are able to induce apoptosis, exert cell cycle blocking, and sensitize tumor cells for chemo- and radiotherapy. A few years ago in vitro, in vivo, and several clinical trials have been described regarding adjuvant IFN-α therapy in the treatment of pancreatic cancer. Some studies reported a remarkable increase in the 2- and 5-year survival. Unfortunately, the only randomized clinical trial did not show a significant increase in overall survival, although the increased median survival implicated that some patients in the experimental group benefited from the adjuvant IFN-α therapy. Furthermore, encouraging in vitro and in vivo data points to a possible role for adjuvant IFN therapy. However, up till now, the use of IFNs in the treatment of pancreatic cancer remains controversial. This review, therefore, aims to describe, based on the available data, whether there is a distinct role for IFN therapy in the treatment of pancreatic cancer.

Targeting both IGF-1R and mTOR synergistically inhibits growth of renal cell carcinoma in vitro

BACKGROUND

Advanced or metastatic renal cell carcinoma (RCC) has a poor prognosis, because it is relatively resistant to conventional chemotherapy or radiotherapy. Treatments with human interferon-α2b alone or in combination with mammalian target of rapamycin (mTOR) inhibitors have led to only a modest improvement in clinical outcome. One observation made with mTOR inhibitors is that carcinomas can overcome these inhibitory effects by activating the insulin-like growth factor-I (IGF-I) signaling pathway. Clinically, there is an association of IGF-I receptor (IGF-IR) expression in RCC and poor long-term patient survival. We have developed a humanized anti-IGF-IR monoclonal antibody, hR1, which binds to RCC, resulting in effective down-regulation of IGF-IR and moderate inhibition of cell proliferation in vitro. In this work, we evaluate the anti-tumor activity of two novel IGF-1R-targeting agents against renal cell carcinoma given alone or in combination with an mTOR inhibitor.

METHODS

hR1 was linked by the DOCK-AND-LOCK™ (DNL™) method to four Fabs of hR1, generating Hex-hR1, or to four molecules of interferon-α2b, generating 1R-2b. Eight human RCC cell lines were screened for IGF-1R expression and sensitivity to treatment with hR1 in vitro. Synergy with an mTOR inhibitor, temsirolimus, was tested in a cell line (ACHN) with low sensitivity to hR1.

RESULTS

Hex-hR1 induced the down-regulation of IGF-IR at 10-fold lower concentrations compared to the parental hR1. Sensitivity to growth inhibition mediated by hR1 and Hex-hR1 treatments correlated with IGF-1R expression (higher expression was more sensitive). The potency of 1R-2b to inhibit the in vitro growth of RCC was also demonstrated in two human cell lines, ACHN and 786-O, with EC50-values of 63 and 48 pM, respectively. When combined with temsirolimus, a synergistic growth-inhibition with hR1, Hex-hR1, and 1R-2b was observed in ACHN cells at concentrations as low as 10 nM for hR1, 1 nM for Hex-hR1, and 2.6 nM for 1R-2b.

CONCLUSIONS

Both Hex-hR1 and 1R-2b proved to be more potent than parental hR1 in inhibiting growth of RCC in vitro. Synergy was achieved when each of the three hR1-based agents was combined with temsirolimus, suggesting a new approach for treating RCC.

Novel interferon-based pre-transplantation conditioning in the treatment of a congenital metabolic disorder

Hematopoietic stem cell (HSC) gene therapy is a potentially curative treatment modality for monogenic hematological diseases and storage disorders. It is necessary, however, to establish pre-bone marrow (BM) transplant conditioning regimens that minimize DNA damage and toxicity. Type I interferon (IFN) signaling activates quiescent HSCs and enables them to be sensitive to 5-fluorouracil (FU)-mediated cytotoxicity, thus implying a molecular basis for improving HSC transplant outcomes. Here we show that type I IFN preconditioning, without irradiation or DNA alkylating agents, significantly enhanced the HSC engraftment efficiency in wild-type (WT) recipient mice. The importance of active type I IFN signaling in HSC recipients was further demonstrated using mice lacking IFN regulatory factor 2 (IRF2), a transcriptional suppressor of type I IFN signaling. In both WT and Irf2(-/-) recipients, active type I IFN signaling greatly enhanced the sensitivity to 5-FU or low-dose irradiation of HSCs. Importantly, IFN-based pre-BM transplant conditioning was also applicable to the treatment of Sly syndrome, a congenital storage disorder with β-glucuronidase deficiency, in which it restored enzyme expression at the HSC level and reciprocally reduced pathological glycosaminoglycan storage. Our findings suggest type I IFN-based preconditioning, combined with HSC transplantation, as a novel nongenotoxic treatment of some congenital diseases.

Stage migration and increasing proportion of favorable-prognosis metastatic renal cell carcinoma patients: implications for clinical trial design and interpretation

BACKGROUND

The Memorial Sloan-Kettering Cancer Center risk model classifies patients with metastatic renal cell carcinoma (RCC) by 5 pretreatment features as favorable, intermediate, and poor risk. The number of Memorial Sloan-Kettering Cancer Center patients in each risk group was examined by year of treatment to analyze stage migration.

METHODS

The distribution of risk groups was examined retrospectively in 789 Memorial Sloan-Kettering Cancer Center patients with metastatic RCC treated in a first-line therapy clinical trial from 1975 to 2007. Date of treatment onset was divided into 6 cohorts between 1975 and 2007 (1975-1980, 1981-1985, 1986-1990, 1991-1995, 1996-2001, and 2001-2007).

RESULTS

The median age of the first-line metastatic RCC clinical trial patients was 59 years (range, 20-82 years). Most patients received cytokine therapy (55%), 37% received chemotherapy/other, and 8% received vascular endothelial growth factor-targeted therapies. Overall survival increased with each consecutive cohort year group (P < .001). Median survival was 0.43 years (95% confidence interval [CI], 0.27-0.68) in the 1973-1980 cohort and 1.5 years in the 2001-2007 cohort (95% CI, 1.15-2.11). Memorial Sloan-Kettering Cancer Center risk-group distribution shifted between 1975 and 2007 (P < .0001). The poor-risk group proportion became smaller (from 44% in 1975-1980 to 13% in 2001-2007), whereas the favorable-risk group increased (from 0% in 1975-1980 to 49% in 2001-2007). The intermediate-risk group remained stable at 50%. After adjusting for type of therapy, the shifts continue to be significant (P < .0001).

CONCLUSIONS

The risk-group distribution for metastatic RCC patients in clinical trials shifted from 1975 to 2007. These shifts have direct implications for data analysis, interpretation of metastatic RCC trends, and drug development.

Metastatic renal cell carcinoma treated with Peg-interferon alfa-2b

INTRODUCTION

Peginterferon has an increased plasma half-life and enables a constant exposure to interferon. This modification might increase the antiangiogenic effect of the treatment and influence the efficacy. We report the results of a phase II open-label study with Peginterferon alfa-2b (Pegintron Schering-Plough) on efficacy and tolerability in patients with advanced renal cell carcinoma (MRCC).

MATERIALS AND METHODS

Twenty eight patients with MRCC were treated with Peginterferon in escalating doses of 0.5 microg/kg once weekly until 2 microg/kg was reached or prohibited toxicity occurred. Lesions were evaluated according to Response Evaluation Criteria in Solid Tumors (RECIST).

RESULTS

Thirteen patients tolerated a dose of 2 microg/kg/week. At 6 months 16 patients (57%) had disease control of which four had partial response (PR) and 12 stable disease whereas 12 (43%) had progressed. PR was only seen in the lung parenchyma or mediastinum. Median time to progression (TTP) was 8 months in all patients and 13 months for PR and SD patients. Correspondingly, median survival was 19.5 months and 28 months, respectively (seven patients received second-line treatment with tyrosine kinase inhibitor). The mean dose during long-term treatment was 1.5 and at the end of treatment 1.2 microg/kg/week. Most side effects were grade 1-2 and only two patients stopped treatment for that reason. VEGF levels in serum before and during treatment did not correlate to the therapeutic response.

DISCUSSION

Peginterferon was well tolerated in MRCC albeit with dose modification during long-term treatment. Response pattern seems to be the same as with nonpegylated interferon. Peginterferon may be used as monotherapy in selected patients and in trials of combinations with targeted drugs.

Fine needle aspiration of renal cortical lesions in adults

The role of fine needle aspiration (FNA) biopsy of renal cortical lesions was controversial in the past because the result of the FNA did not affect clinical management. All renal cortical lesions, except metastasis, were subject to surgical resection. However, with the advances in neoadjuvant targeted therapies, knowledge of the renal cortical tumor histological subtype is critical for tailoring clinical trials and follow-up strategies. At present, there are clinical trials involving the use of novel kinase inhibitors for conventional (clear cell) and papillary renal cell carcinoma. We studied 143 consecutive cases of renal cortical lesions, evaluated after radical or partial nephrectomies over a 2-year period. An air-dried smear and a Thinprep® slide were prepared in all cases. The slides were Diff-Quick and Papanicolaou stained, respectively. The cytology specimens were reviewed and the results were then compared with the histologic diagnosis. Cytology was highly accurate to diagnose conventional RCC, while the accuracy for papillary RCC, chromophobe RCC, and papillary urothelial carcinoma was much lower. Our results indicate that ancillary studies might have an important role in the subclassification of renal cortical neoplasms for targeted treatment.

Phase II, randomized, multicenter, comparative study of peginterferon–α–2a (40 kD) (Pegasys®)versusinterferon α-2a (Roferon®-A) in patients with treatment-naïve, chronic-phase chronic myelogenous leukemia

The efficacy and safety of peginterferon-alpha-2a (40 kD) (PEG-IFNalpha-2a), 450 microg once weekly, versus IFNalpha-2a, 9 MIU once daily, for 12 months, was evaluated in a Phase II study in IFN-naïve patients with chronic-phase, Philadelphia-chromosome-positive CML. At the end of the treatment, complete hematological response was observed in 66.2% (47/71) and 45.2% (33/73) of the PEG-IFNalpha-2a group and IFNalpha-2a groups, respectively (p = 0.009), and major cytogenetic response occurred in 35.2% and 17.8%, respectively (p = 0.016). PEG-IFNalpha-2a was at least as effective as IFNalpha-2a overall, including progression-free survival at the end of treatment, and overall survival after 30 months of follow-up. Adverse events necessitated fewer withdrawals but more dose adjustments in the PEG-IFNalpha-2a group compared with the IFNalpha-2a group (11%versus 23%, and 84.5%versus 65.8%, respectively). In conclusion, PEG-IFNalpha-2a (40 kD), 450 microg once weekly, compared with IFNalpha-2a, 9 MIU once daily, resulted in higher rates of hematologic and cytogenetic response and greater overall survival.

Race affects access to nephrectomy but not survival in renal cell carcinoma

OBJECTIVES

To assess whether, in contemporary patients with renal cell carcinoma (RCC), access to nephrectomy is the same between the Blacks and Whites, and that there is no difference in mortality after stratification for treatment type.

PATIENTS AND METHODS

The effect of race has received little attention in RCC; only two reports have addressed and suggested the presence of racial disparities, including access to nephrectomy and survival after nephrectomy, where Black patients were disadvantaged relative to Whites. We used the Surveillance, Epidemiology and End Results data from 12 516 patients of all stages diagnosed and treated for RCC between 2000 and 2004. The effect of race (Black vs White) on nephrectomy rate was addressed in logistic regression and binomial regression models, and Cox regression models tested the effect of race on overall survival.

RESULTS

Black patients were 50% less likely to have a nephrectomy than their White counterparts. However, race had no effect on overall survival when the entire cohort was assessed, as well as in subgroups of patients with or without nephrectomy.

CONCLUSIONS

Although race is a determinant of access to nephrectomy, it should not be interpreted as a barrier to care, as survival was unaffected by race in patients having a nephrectomy or not. Instead, race might represent a proxy of comorbidity and life-expectancy, which represent surgical selection criteria for nephrectomy.

Novel Delivery Systems for Interferons

Interferons, IFNs, are among the most widely studied and clinically used biopharmaceuticals. Despite their invaluable therapeutic roles, the widespread use of IFNs suffers from some inherent limitations, mainly their relatively short circulation lifespan and their unwanted effects on some non-target tissues. Therefore, both these constraints have become the central focus points for the research efforts on the development of a variety of novel delivery systems for these therapeutic agents with the ultimate goal of improving their therapeutic end-points. Generally, the delivery systems currently under investigation for IFNs can be classified as particulate delivery systems, including micro- and nano-particles, liposomes, minipellets, cellular carriers, and non-particulate delivery systems, including PEGylated IFNs, other chemically conjugated IFNs, immunoconjugated IFNs, and genetically conjugated IFNs. All these strategies and techniques have their own possibilities and limitations, which should be taken into account when considering their clinical application. In this article, currently studied delivery systems/techniques for IFN delivery have been reviewed extensively, with the main focus on the pharmacokinetic consequences of each procedure.

Emerging drugs in cutaneous T-cell lymphomas

Cutaneous T-cell lymphomas are a heterogeneous group of rare lympho-proliferative disorders. In most cases, they are characterised by the accumulation of clonal CD4+ lymphocytes in the skin. Extracutaneous involvement is present in late stages only. Unfortunately, only few drugs are registered for these disfiguring diseases. Skin-directed therapies using topical formulations are the preferred first-line modalities for cutaneous lesions in early stages. In this field there are interesting developments using topical retinoids and gene therapy products, such as adeno-IFN-gamma. Systemic treatment uses biologicals, such as fusion molecules, monoclonal antibodies and immune response modifiers (IFNs, retinoids), and well-tolerated antiproliferative drugs, such as histone deacetylase inhibitors or liposomal doxorubicin.

Future perspectives in the treatment of cutaneous T-cell lymphoma (CTCL)

Over the last 20 years the treatment of cutaneous T-cell lymphoma has been in a state of continual change. New therapies are constantly emerging as the search continues for more effective and tolerable disease-specific agents that satisfy medical needs. Therapies under investigation include topical retinoids, fusion molecules like denileukin diftitox, pegylated interferon, interleukin-2, and interleukin-12. Pegylated liposomal doxorubicin, gemcitabine, and chlorodeoxyadenosine also appear to have clinical potential. Other identified agents include vaccines and monoclonal antibodies. This article reviews some of the most recent clinical innovations.

Randomized dose-escalation study evaluating peginterferon alfa-2a in patients with metastatic malignant melanoma

PURPOSE

A pegylated interferon, peginterferon alfa-2a (PEG-IFNalpha-2a; 40 kd), has the potential for improved tumor response and survival with lower toxicity than IFNalpha. This open-label, randomized study evaluated the safety, tolerability, and efficacy of subcutaneous PEG-IFNalpha-2a in patients with metastatic malignant melanoma (stage IV American Joint Committee on Cancer staging system).

PATIENTS AND METHODS

PEG-IFNalpha-2a was administered subcutaneously at 180 (n = 48), 360 (n = 53), or 450 mug (n = 49) once weekly for 24 weeks, with maintenance therapy for responders. Efficacy was assessed by the proportion of patients with complete response (CR) or partial response (PR).

RESULTS

The major response rate (CR or PR) was 6% in the 180-mug group (CR, 2%; PR, 4%), 8% in the 360-mug group (CR, 2%; PR, 6%), and 12% in the 450-mug group (CR, 6%; PR, 6%). The times to achieve a major response, duration of major response, rate of disease progression, and 12-month survival were similar between groups, although overall median survival was significantly different among the three groups (P = .0136). More patients required dose adjustment for safety reasons in the higher dose groups, but PEG-IFNalpha-2a was generally well tolerated, with few withdrawals because of adverse events (6%, 19%, and 16% in the 180-, 360-, and 450-mug groups, respectively). The most common adverse events were fatigue, pyrexia, and nausea.

CONCLUSION

PEG-IFNalpha-2a at doses up to 450 mug once weekly has shown good tolerability and similar efficacy to conventional IFNalpha and monochemotherapy in stage IV metastatic melanoma.

Transcriptional Program Associated with IFN-αResponse of Renal Cell Carcinoma

Metastatic renal cell carcinoma (RCC) is refractory to therapy; however, 10%-20% of patients respond favorably with interferon-alpha (IFN-alpha) treatment. To understand the molecular basis of response to IFN-alpha therapy, we performed global gene expression analysis of sensitive and resistant RCC cell lines in the absence and in the presence of IFN-alpha, using high-density oligonucleotide arrays to detect differentially expressed genes. In the absence of IFN-alpha, no significant differences in gene expression were observed between six sensitive and six resistant cell lines. Gene expression analysis following a time course of IFN-alpha2b treatment in one sensitive (SK-RC-17) and one resistant (SK-RC-12) cell line revealed that 484 and 354 transcripts, respectively, were modulated. A considerable number of these transcripts were similarly modulated between the two cell types that included several known targets of IFN signaling associated with antiviral and immunomodulatory activity. A further analysis of gene expression pattern in response to IFN revealed that several transcripts associated with proapoptotic function were upregulated in the sensitive cells. In the resistant cells, transcripts associated with cell survival and proliferation were induced, and key apoptotic molecules were suppressed. This study suggests that the IFN-alpha response of individual RCC tumors is determined by the expression pattern of genes in the apoptosis vs. survival and proliferation pathways rather than by alterations in expression of one or more individual genes.

Interferon alpha for the treatment of advanced renal cancer

This paper is an overview on the place of IFN-alpha in metastatic renal cell carcinoma (MRCC). After a presentation of MRCC and the mode of action of IFN-alpha, the results of studies including IFN-alpha alone or in combination with IL-2, chemotherapy and other biological modifiers are presented. Finally, new trends for new drugs, including antiangiogenic therapies, are discussed.

Randomized, placebo-controlled trial of nonpegylated and pegylated forms of recombinant human alpha interferon 2a for suppression of dengue virus viremia in rhesus monkeys

Dengue fever and dengue hemorrhagic fever are caused by infection with any one of the four dengue viruses (DVs) and are significant public health burdens throughout the tropics. Higher viremia levels are associated with greater dengue disease severity. A therapeutic intervention to suppress viremia early in DV infection could potentially ameliorate severe disease. Recombinant alpha interferon 2a (rIFN-alpha-2a, Roferon-A) suppressed DV replication in human peripheral blood mononuclear cells in vitro. We therefore examined the effects of rIFN-alpha-2a and pegylated recombinant IFN-alpha-2a (PEG-rIFN-alpha-2a, PEGASYS) on DV serotype 2 (DV-2) viremia in rhesus monkeys. Flavivirus-naïve monkeys were inoculated with DV-2 and randomized to receive a single dose of rIFN-alpha-2a (10 million international units/m2) versus placebo or PEG-rIFN-alpha-2a (6 microg/kg) versus placebo 1 day after the onset of viremia. Serial daily viremia levels were measured, and convalescent-phase DV-2 neutralizing antibody titers were determined. Compared to placebo, a single injection of rIFN-alpha-2a temporarily suppressed DV-2 replication and delayed the time to peak viremia by a median of 3 days. However, measures of total viral burden were not different between the two groups. A single injection of PEG-rIFN-alpha-2a significantly lowered daily viremia levels and improved virus clearance, starting 48 h after administration. There were no significant differences in DV-2 neutralizing antibody titers between the treatment and placebo groups at 30 and 90 days postinfection. Based on their individual effects, future studies should investigate a combination of rIFN-alpha-2a and PEG-rIFN-alpha-2a for suppression of dengue virus viremia and as a potential therapeutic intervention.

Review: Milstein Award lecture: interferons and cancer: where from here?

Interferons (IFNs) remain the most broadly active cytokines for cancer treatment, yet ones for which the full potential is not reached. IFNs have impacted positively on both quality and quantity of life for hundreds of thousands of cancer patients with chronic leukemia, lymphoma, bladder carcinoma, melanoma, and renal carcinoma. The role of the IFN system in malignant pathogenesis continues to enhance understanding of how the IFN system may be modulated for therapeutic advantage. Reaching the full potential of IFNs as therapeutics for cancer will also result from additional understanding of the genes underlying apoptosis induction, angiogenesis inhibition, and influence on immunologic function. Food and Drug Administration (FDA) approval of IFNs occurred less than 20 years ago; after 40 years, third-generation products of early cytotoxics, such as 5- fluorouracil (5FU), are beginning to reach clinical approval. Thus, substantial potential exists for additional application of IFNs and IFN inducers as anticancer therapeutics, particularly when one considers that their pleiotropic cellular and molecular effects have yet to be fully defined.

Emerging drugs for renal cell carcinoma

Renal cell carcinoma (RCC) still represents a therapeutic challenge when patients have advanced or metastatic disease. Treatment using IL-2 and IFN-alpha continues to be the standard of care in patients who are able to tolerate such regimens. Targeted therapy may become the first-line treatment for patients resistant or intolerant to cytokines as new emerging drugs continue to be investigated. Understanding the genetic abnormalities related to the development of RCC (e.g., VHL gene abnormalities) and identifying molecular targets (e.g., epidermal growth factor, vascular endothelial growth factor and carbonic anhydrase IX) are playing a major role in the emergence of these novel agents for the treatment of this malignancy. Overall, these drugs are better tolerated and more acceptable to use by patients than the traditional cytokine-based regimens. The use of oral drugs to treat various malignancies including RCC seems to be the new paradigm of the future. Further understanding of their mechanisms of action and confirmation of their benefits on the clinical outcome is needed.

Phase I Evaluation of a 40-kDa Branched-Chain Long-Acting Pegylated IFN-α-2a With and Without Cytarabine in Patients with Chronic Myelogenous Leukemia

PURPOSE

Pegasys (PEG-IFN) is a modified form of recombinant human IFN-alpha-2a in which IFN-alpha is attached to a branched methoxypolyethylene glycol (PEG) moiety of large molecular weight (40 kDa). Such molecular modification results in sustained absorption after s.c. drug administration and a prolonged half-life. A phase I study of PEG-IFN was conducted in patients with chronic myelogenous leukemia (CML) who were previously treated with IFN-alpha to evaluate the effect of sustained exposure to IFN on patients with CML.

EXPERIMENTAL DESIGN

Twenty-seven patients with long-term or IFN-refractory CML were enrolled in cohorts of three or six patients. PEG-IFN was given once weekly by s.c. injections starting at a dose of 270 microg/wk to a maximum dose of 630 microg/wk. Sixteen additional patients were treated with escalating doses of PEG-IFN ranging from 450 to 540 microg/wk in combination with two different schedules of low-dose cytarabine (1-beta-D-arabinofuranosylcytosine, ara-C). Serial venous blood samples were collected to evaluate the pharmacokinetic and pharmacodynamic characteristics of PEG-IFN in these patients.

RESULTS

The dose-limiting toxicity (DLT) as defined by the protocol was not achieved at the highest dose tested of 630 mug/wk. With the addition of ara-C, the DLT was reached at 540 microg/wk. The safety profile was similar to that of unmodified IFNs. Of 27 patients treated with PEG-IFN, 14 (52%) achieved or maintained a complete hematologic response and three (11%) achieved a complete cytogenetic response. Among 16 patients treated with the combination of PEG-IFN and ara-C, 11 (69%) achieved or maintained complete hematologic remission and two (13%) achieved complete cytogenetic remission. The mean serum peak concentration (C(max)) of PEG-IFN increased from 9.4 to 28 ng/mL as the dose increased from 270 to 450 microg/wk, with no further increases in C(max) at higher dose levels. Serum concentration reached peak value starting about 48 hours after drug administration and was maintained at close to peak value throughout the dosing interval. The mean +/- SD area under the serum concentration-time curve (AUC) calculated after the first dose also increased from 1,022 +/- 694 to 3,343 +/- 2,728 ng hour/mL as dose was increased from 270 to 450 microg/wk, showing a dose-related increase in systemic exposure of PEG-IFN. As with C(max), the AUC did not increase at higher dose levels. The maximum induction (E(max)) of neopterin, the surrogate marker of the pharmacodynamic activity of PEG-IFN, increased from 120% to 361% over baseline values as the dose was increased from 270 to 540 microg/wk. On the once-weekly multiple dosing schedule, both the PEG-IFN and neopterin concentration seemed to reach steady state by week 5 and the steady-state values were maintained with chronic dosing over 6 months.

CONCLUSION

Pegasys provided a significant advantage over standard IFN-alpha by enabling once-weekly dosing while maintaining acceptable safety, tolerability, and activity profiles. This branched 40-kDa PEG-IFN was well tolerated both as a monotherapy as well as in combination with ara-C. Demonstration of its sustained exposure, pharmacodynamic activity, hematologic response, and evidence of cytogenetic response in several patients in this limited study with either IFN-refractory or INF-intolerant patients provides a promise for further investigation in combination with new agents like imatinib.

Novel treatments for metastatic renal cell carcinoma

The mainstay of any curative treatment in renal cell carcinoma (RCC) is surgery. In case of metastatic disease at presentation a radical nephrectomy is recommended to good performance status patients prior to start of interferon-alfa treatment. Interferon-alpha (IFN-alpha) offers in a small but significant percentage of patients advantage in overall survival; interleukin-2 (IL-2) based therapy gives similar survival rates. To date hormonal and chemotherapy do not have a proven impact on survival. The recent new insights in the molecular biology of clear RCC has revealed a key-role for vascular endothelial growth factor (VEGF) in the stimulation of angiogenesis in this highly vascularized tumour. This opens interesting new treatment strategies including: blockage of VEGF with the monoclonal antibody bevacizumab and inhibition of VEGF receptor tyrosine kinases (with small oral molecules such as SU11248 or PTK787). Likewise, inhibition of the Raf kinase pathway (with oral Bay 43-9006) or inhibition of the mTOR pathway (with i.v. CCI-779) are under investigation. Preliminary clinical results with all these compounds are interesting and the results of ongoing phase III studies will become available in the next years.

A phase-II study of pegylated interferon alfa-2b for patients with metastatic renal cell carcinoma and removal of the primary tumor

Twenty-two patients with metastatic renal cell carcinoma and removal of the primary tumor were treated with subcutaneous pegylated interferon alfa-2b (PEG-Intron) to evaluate toxicity and efficacy. Start dose was 3.0 microg/kg/week, escalated to 6.0 microg/kg/week. After 2 months, therapy was extended in case of response or stable disease (SD) until progressive disease (PD) or relapse for a maximum of 2 years. National Cancer Institute common toxicity criteria (NCI-CTC) were monitored every 2-4 weeks. After 2 months, nine patients did not continue (8 PD, 1 SD with grade 4 CTC) and 13 extended treatment [three partial response (PR), 10 SD], of these, 11 progressed. One patient with PR developed a durable complete response later. Overall response rate was 13.6% (3/22). Median overall survival is 13 months (range 3-35 months). Dosage was escalated to 6 microg/kg/week in three patients. NCI-CTC grade 2 and 3 required dose attenuation in 12 patients during escalation, and reduction in 10 during the trial. Three patients discontinued because of grade 4 CTC (two fatigue, one hyperglycemia). Fatigue was the major dose-limiting toxicity. These results suggest an efficacy and toxicity of PEG-Intron comparable to standard interferon alfa-2b in patients with mRCC and removal of the primary tumor.

Peginterferon alfa-2a: A review of approved and investigational uses

BACKGROUND

In October 2002, the US Food and Drug Administration approved peginterferon alfa-2a for the management of chronic hepatitis C virus (HCV) infection. The addition of polyethylene glycol (PEG) moiety to the interferon (IFN) molecule results in a product with altered pharmacokinetic properties.

OBJECTIVE

The aim of this article is to review the pharmacology, medications interactions, adverse events (AEs), and approved or investigational uses of PEG-IFN alfa-2a for viral hepatitis and oncologic conditions.

METHODS

Relevant articles were identified through searches of MEDLINE (1980-July 2003) and EMBASE (1980-July 2003). Search terms included, but were not limited to, peginterferon alfa-2a, pharmacokinetics, pharmacology, pharmacodynamics, and therapeutic use, as well as terms for specific disease states and AEs. Further publications were identified from citations of resulting papers.

RESULTS

Pegylation of IFN alfa-2a results in major changes in the pharmacokinetics of the product. Absorption is prolonged and serum concentrations are sustained over the dosing regimen. PEG-IFN alfa-2a has been shown to be more effective with or without ribavirin (RBV), in the management of treatment-naive patients with chronic HCV infection, than unmodified IFN alfa-2a with or without RBV. Results in other disease states are still preliminary. AEs are similar, in incidence and severity, to those occurring with unmodified IFN. They include earlier hematologic symptoms and fewer influenza-like symptoms. Drug-drug interactions are the same as those occurring with the unmodified IFN product.

CONCLUSIONS

The pharmacokinetic profile of IFN alfa-2a is improved by pegylation, which enables less frequent administration and results in improved efficacy with a similar side-effect profile. Combination of PEG-IFN alfa-2a with RBV is associated with a greater chance of achieving a sustained virologic response in treatment-naive patients with chronic HCV, compared with unmodified IFN alfa-2a/RBV combinations. Documentation of efficacy in other conditions awaits results of controlled clinical trials.

Interferon Alfa-2b Three Times Daily and Thalidomide in the Treatment of Metastatic Renal Cell Carcinoma

Purpose: The antiangiogenic effect of interferon (IFN) may improve with frequent dosing and by combination with other agents with antiangiogenic activity. To evaluate this potential, we treated patients with metastatic renal cell carcinoma (RCC) with frequently dosed IFN and thalidomide.

Patients and Methods: Thirty patients were given IFN-α-2b 0.9 MU subcutaneously three times daily for 1 month and subsequently 1.2 MU tid unless serious toxicity was encountered. Thalidomide was first given 100 mg/d for 1 week and 300 mg/d thereafter. Sera were collected before and during treatment for serum vascular endothelial growth factor (S-VEGF) analyses performed using enzyme-linked immunosorbent assay.

Results: The intention-to-treat response rate was 20% (95% CI, 6% to 34%) and response rate for assessable patients (n = 27) was 22% (95% CI, 6% to 38%). All responses were partial. In addition, 17 patients (63%; 95% CI, 45% to 81%) had stable disease for 3 months or longer. The median time to treatment failure was 7.7 months, and median survival time was 14.9 months. The most common cause of thalidomide discontinuation was neuropathy. S-VEGF levels decreased more in patients who responded to therapy compared with those in patients whose condition had stabilized or who had progressive disease (P = .036).

Conclusion: The combination of frequently dosed IFN-α-2b and low-dose thalidomide is feasible and active in advanced RCC, but the clinical benefit may remain small compared with that of IFN alone. Results from an ongoing phase III trial comparing IFN-α with or without thalidomide need to be analyzed before this combination can be recommended for use outside clinical studies.

Response assessment classification in patients with advanced renal cell carcinoma treated on clinical trials

BACKGROUND

The objective of the current study was to evaluate the effect on response assessment classification in patients with metastatic renal cell carcinoma (RCC) using unidimensional (Response Evaluation Criteria in Solid Tumors) and bidimensional (World Health Organization) criteria, including or excluding measurements of the primary renal tumor and using a new index to compensate for the disproportionate effect of large renal tumors relative to their metastases.

METHODS

Fifty-three imaging studies involving a total of 44 patients with metastatic RCC who were treated on clinical trials of interferon-alpha analogue and/or thalidomide were reviewed retrospectively. The best overall response assessment and progression free survival were calculated with both unidimensional and bidimensional tumor measurements. Patients were then stratified into two groups: patients with primary renal tumors in situ and patients who underwent resection of their primary renal tumors. The best overall response and the time to disease progression were calculated based on the sum of measurements (conventional methodology), both including and excluding the primary tumor. A new method of response assessment, the 'normalized lesion index', which equalizes the differences in tumor size for an individual patient, was evaluated and compared with the conventional response assessment.

RESULTS

There was an 11% disagreement rate in the best overall response assessment between unidimensional and bidimensional measurements. The time to progression was 9.2 months measured unidimensionally, compared with 6.4 months assessed bidimensionally. In the group of patients who had primary renal tumors in situ, using the conventional sum of measurements method, the apparent time to progression was an average of 4.2 months longer compared with measurements that did not include the primary renal tumor. The use of the normalized lesion index method resulted in an improved concordance in best overall response assessments and similar time to progression assessments when the primary renal tumor was included compared with patients who did not have primary renal tumors in situ.

CONCLUSIONS

The use of unidimensional measurements in RCC therapy assessment results in significantly different time to progression classification compared with the use of bidimensional measurements. Response assessment classification in patients with RCC is affected by the exclusion or inclusion of measurements of the primary renal tumor. The normalized lesion index warrants further study in assessing response in patients with metastatic RCC and other solid tumor malignancies that often show substantial differences in sizes of measurable lesions.

Pegylation: engineering improved biopharmaceuticals for oncology

Pegylation, the technology of polyethylene glycol (PEG) conjugation, holds significant promise in maintaining effective plasma concentrations of systemically administered drugs that might otherwise be hampered in vivo by a number of factors, such as rapid elimination by the kidneys. Mobile, nontoxic PEG chains can be conjugated to biotherapeutics, increasing their hydrodynamic volume, which can in turn prolong their plasma retention time, increase their solubility, and shield antigenic determinants on the drug from detection by the immune system. Attaching PEG molecules for optimal pharmacokinetics without obstructing the active sites that are essential for drug efficacy is a major challenge in pegylation. Current pegylation technology uses linkerless conjugation methods to produce coupling without added toxicity or immunogenicity, and may keep the innate surface charge of the pegylated molecule intact. In addition to controlling the size and complexity of PEG molecules, the attachment site can be manipulated to avoid steric hindrance of the drug's active receptor-recognition or substrate-interaction site. A few pegylated drugs have been engineered to have an improved pharmacokinetic profile with preserved bioactivity. They often have prolonged steady plasma concentrations in vivo, thereby making a reduced number of doses possible. Other interesting effects have also emerged, such as the self-regulating pharmacokinetics of pegfilgrastim, a pegylated version of the granulocyte colony-stimulating factor filgrastim that is administered for management of chemotherapy-induced neutropenia. The improved dosing schedule, with longer intervals between administrations of the pegylated agents, will improve compliance and quality of life in patients with chronic disease.

Novel therapies for renal cell carcinoma--an update

This article reviews the recent progress in the search for new treatments for renal cell cancer (RCC), based on a variety of preclinical models or strategies. Some recent clinical trials addressing migrating treatments from other cancers onto RCC and novel agents are discussed, as well as the molecular targets for some of the novel agents. Drugs oriented to histologically definable RCC features, such as the G250 antigen, and the receptor tyrosine kinases, such as epidermal growth factor receptor, are reviewed. Drugs aimed at antiangiogenesis and perturbing features of the cell cycle are also mentioned, including preclinical and empirical experience. Molecular techniques in the study of von Hippel Lindau-related pathways and mRNA expression analyses are cited. Within the immune model of therapy, progress in the application of immune-related drugs including older cytokines (IL-2, IFN-alpha) and of newer cytokine-variant and other cytokines are discussed. Finally, cell-based therapies such as lymphocyte infusions, tumour-cell vaccines, dendritic cell vaccines and allogeneic mini-transplant are outlined. Although high percentage improvements in outcomes for metastatic RCC are not yet realised, the many fronts for scientific and clinical advances form some basis for optimism in the coming years.