Serum concentrations of pegylated interferon α-2b in patients with resected stage III melanoma receiving adjuvant pegylated interferon α-2b in a randomized phase III trial (EORTC 18991)

Systemic adjuvant therapy for adult patients at high risk for recurrent melanoma: A systematic review

Cutaneous melanoma is typically treated with wide local excision and, when appropriate, a sentinel node biopsy. Many patients are cured with this approach but for patients who have cancers with high risk features there is a significant risk of local and distant relapse and death. Interferon-based adjuvant therapy was recommended in the past but had modest results with significant toxicity. Recently, new therapies (immune checkpoint inhibitors and targeted therapies) have been found to be effective in the treatment of patients with metastatic melanoma and many of these therapies have been evaluated and found to be effective in the adjuvant treatment of high risk patients with melanoma. This systematic review of adjuvant therapies for cutaneous and mucosal melanoma was conducted for Ontario Health (Cancer Care Ontario) as the basis of a clinical practice guideline to address the question of whether patients with completely resected melanoma should be considered for adjuvant systemic therapy and which adjuvant therapy should be used.

Thyroid dysfunction as an unintended side effect of anticancer drugs

BACKGROUND

Several of the currently used anticancer drugs may variably affect thyroid function, with impairment ranging from modified total but not free concentration of thyroid hormones to overt thyroid disease.

SUMMARY

Cytotoxic agents seem to alter thyroid function in a relatively small proportion of adult patients. Anticancer hormone drugs may mainly alter serum levels of thyroid hormone-binding proteins without clinically relevant thyroid dysfunction. Old immunomodulating drugs, such as interferon-α and interleukin-2, are known to induce variably high incidence of autoimmune thyroid dysfunction. Newer immune checkpoint inhibitors, such as anti-CTLA4 monoclonal antibodies, are responsible for a relatively low incidence of thyroiditis and may induce secondary hypothyroidism resulting from hypophysitis. Central hypothyroidism is a well-recognized side effect of bexarotene. Despite their inherent selectivity, tyrosine kinase inhibitors may cause high rates of thyroid dysfunction. Notably, thyroid toxicity seems to be restricted to tyrosine kinase inhibitors targeting key kinase-receptors in angiogenic pathways, but not other kinase-receptors (e.g., epidermal growth factor receptors family or c-KIT). In addition, a number of these agents may also increase the levothyroxine requirement in thyroidectomized patients.

CONCLUSIONS

The pathophysiology of thyroid toxicity induced by many anticancer agents is not fully clarified and for others it remains speculative. Thyroid dysfunction induced by anticancer agents is generally manageable and dose reduction or discontinuation of these agents is not required. The prognostic relevance of thyroid autoimmunity, overt and subclinical hypothyroidism induced by anticancer drugs, the value of thyroid hormone replacement in individuals with abnormal thyrotropin following anticancer systemic therapy, and the correct timing of replacement therapy in cancer patients need to be defined more accurately in well-powered prospective clinical trials.

Population pharmacokinetics of peginterferon alfa-2b in pediatric patients with chronic hepatitis C

PURPOSE

The aim of this study was to characterize the population pharmacokinetics of peginterferon (PEG-IFN) alfa-2b in pediatric patients with chronic hepatitis C and to identify covariates influencing PEG-IFN alfa-2b disposition.

METHODS

Pharmacokinetic data from a multicenter open-label study of subcutaneously administered peginterferon alfa-2b (60 μg/m(2)/wk) plus oral ribavirin (15 mg/kg/day) in patients with chronic hepatitis C aged 3-17 years old was used to develop a population pharmacokinetic nonlinear mixed-effects model.

RESULTS

The final population pharmacokinetic analysis was conducted with the pooled data from 107 pediatric patients. A one-compartment model with first-order absorption, first-order elimination, exponential inter-individual variability on clearance, and a combination additive and proportional residual error model adequately described the PEG-IFN alfa-2b pharmacokinetic profile. Age (apparent clearance and apparent volume of distribution) and sex (apparent clearance) were significant covariates. The mean body surface area normalized apparent clearance of PEG-IFN alfa-2b was 0.56 L/h/m(2), and was similar when evaluated across the pediatric age groups.

CONCLUSION

The final population model suggests age-dependent increases in clearance and volume of distribution of PEG-IFN alfa-2b in pediatric patients with chronic hepatitis C. The apparent clearance normalized to body surface area was similar across pediatric age groups, supporting the use of body size-adjusted dosing in pediatric subjects.

An update on pegylated IFN-α2b for the adjuvant treatment of melanoma

For patients with localized melanoma, excision of the primary tumor, including lymphadenectomy for nodal metastases, is standard treatment. However, patients with large primary tumors (stage IIB and IIC) or stage III melanoma have a relatively poor prognosis owing to the high risk of recurrence. High-dose IFN-α2b and pegylated IFN-α2b (PEG-IFN-α2b) are the only approved options for adjuvant therapy of stage III melanoma, but the lack of comparative data has led to considerable confusion in choosing between these options. In this article, current evidence regarding the pharmacokinetics, efficacy, safety and tolerability of adjuvant PEG-IFN-α2b in patients with melanoma is reviewed, with frequent reference to and comparisons with data using IFN-α2b. Particular focus is given to the pharmacokinetic differences between IFN-α2b and PEG-IFN-α2b and their implications for the treatment of high-risk patients. In addition, emerging evidence suggests that PEG-IFN-α2b therapy may provide clinically significant overall survival benefit for selected high-risk patients.

Autoimmunity and treatment outcome in melanoma

PURPOSE OF REVIEW

Only a subset of melanoma patients with advanced disease seems to benefit from immunotherapy. Predictive markers identifying these patients are unfortunately not available. Whether immune-related side effects could serve as predictors for treatment response or just resemble unwanted side effects from immunotherapy will be outlined in this review.

RECENT FINDINGS

Early studies suggested an association of immune-related side effects such as vitiligo and autoimmune thyroiditis with response in patients receiving IL-2 or IFNα. However, conflicting data have been reported as well, mentioning the effect of a higher rate of immune-related toxicities during prolonged administration of the drug in responders/survivors. This type of bias is also known as guarantee-time bias. Recently, a clearly significant and clinically relevant prolongation of survival was demonstrated in patients with metastatic melanoma treated with ipilimumab. Immune-related adverse events were associated with response to ipilimumab, however, at the cost of considerable toxicity.

SUMMARY

Evidence for an association of immune-related toxicities and response in patients receiving IL-2 or IFNα is weak, considering guarantee-time bias. On the contrary, this association for patients receiving anti-cytotoxic T-lymphocyte antigen-4 therapy (ipilimumab) appears much stronger. Importantly, can we uncouple tumor immunity from autoimmunity in order to optimize immunotherapy in melanoma?

Immunotherapy for melanoma: current status and perspectives

Immunotherapy is an important modality in the therapy of patients with malignant melanoma. As our knowledge about this disease continues to expand, so does the immunotherapeutic armamentarium. Nevertheless, successful preclinical models do not always translate into clinically meaningful results. The authors give a comprehensive analysis of most recent advances in the immune anti-melanoma therapy, including interleukins, interferons, other cytokines, adoptive immunotherapy, biochemotherapy, as well as the use of different vaccines. We also present the fundamental concepts behind various immune enhancement strategies, passive immunotherapy, as well as the use of immune adjuvants. This review brings into discussion the results of newer and older clinical trials, as well as potential limitations and drawbacks seen with the utilization of various immune therapies in malignant melanoma. Development of novel therapeutic approaches, along with optimization of existing therapies, continues to hold a great promise in the field of melanoma therapy research. Use of anti-CTLA4 and anti-PD1 antibodies, realization of the importance of co-stimulatory signals, which translated into the use of agonist CD40 monoclonal antibodies, as well as activation of innate immunity through enhanced expression of co-stimulatory molecules on the surface of dendritic cells by TLR agonists are only a few items on the list of recent advances in the treatment of melanoma. The need to engineer better immune interactions and to boost positive feedback loops appear crucial for the future of melanoma therapy, which ultimately resides in our understanding of the complexity of immune responses in this disease.

Pharmacokinetic/pharmacodynamic analysis of adjuvant pegylated interferon α-2b in patients with resected high-risk melanoma

Purpose

High-dose pegylated interferon α-2b (peginterferon α-2b) significantly decreased disease recurrence in patients with resected stage III melanoma in a clinical study. We investigated the pharmacokinetics (PK) and safety of high-dose peginterferon α-2b in patients with high-risk melanoma.

Methods

For PK analysis, 32 patients received peginterferon α-2b 6 μg/(kg week) subcutaneously for 8 weeks (induction) then 3 μg/(kg week) for 4 weeks (maintenance). PK profiles were determined at weeks 1, 8, and 12. Exposure–response relationships between peginterferon α-2b and absolute neutrophil count (ANC) and alanine aminotransferase (ALT) level were also studied.

Results

Peginterferon α-2b was well-absorbed following SC administration, with a median T_max of 24 h. Mean half-life estimates ranged from 43 to 51 h. The accumulation factor was 1.69 after induction therapy. PK parameters showed moderate interpatient variability. PK profiles were described by a one-compartmental model with first-order absorption and first-order elimination. Toxicity was profiled and was acceptable; observed side effects were similar to those previously described. Dose reduction produced proportional decreases in exposure and predictable effects on ANC in an Imax model; however, a PK/pharmacodynamic (PK/PD) relationship between peginterferon α-2b and ALT could not be established with high precision.

Conclusions

Peginterferon α-2b was well-absorbed and sustained exposure to peginterferon α-2b was achieved with the doses tested. These data confirm and extend previous PK observations of peginterferon α-2b in melanoma and solid tumors. Our PK/PD model of exposure and ANC effect provides useful information for prediction of peginterferon α-2b-related hematologic toxicity.

Electronic supplementary material

The online version of this article (doi:10.1007/s00280-010-1326-9) contains supplementary material, which is available to authorized users.

Phase III trial comparing adjuvant treatment with pegylated interferon Alfa-2b versus observation: prognostic significance of autoantibodies--EORTC 18991

PURPOSE

Conflicting data have been reported concerning the prognostic value of autoimmune antibodies in patients with melanoma treated with adjuvant interferon alfa-2b (IFN). We evaluated the prognostic significance of autoantibodies in the European Organisation for Research and Treatment of Cancer 18991 trial, comparing long-term administration of pegylated IFN (PEG-IFN) with observation.

PATIENTS AND METHODS

Anticardiolipin, antithyroglobulin, and antinuclear antibodies were determined by enzyme-linked immunosorbent assays in 296 patients before random assignment and every 6 months after random assignment for up to 5 years. Prognostic impact of autoantibodies on recurrence-free survival (RFS) was assessed using the following three Cox models: a model that considered autoantibody appearance as a time-independent variable (model 1); a model that considered a patient to be autoantibody positive from the first positive test (model 2); and a model in which the most recent autoantibody test was used to define the status of the patient (model 3).

RESULTS

Patients who were autoantibody negative at baseline were analyzed (n = 220). Occurrence of autoantibodies during follow-up was higher in the PEG-IFN-treated patients (18% in the observation arm v 52% in the PEG-IFN arm). Autoantibody appearance was of prognostic importance by using model 1 (hazard ratio [HR] = 0.56; 95% CI, 0.36 to 0.87; P = .01). However, when guarantee-time bias was taken into account using model 2 (HR = 1.19; 95% CI, 0.75 to 1.88; P = .46) or method 3 (HR = 1.14; 95% CI, 0.71 to 1.83; P = .59), significance was lost. Results were similar when treatment groups were analyzed separately.

CONCLUSION

Appearance of autoimmune antibodies is neither a prognostic nor a predictive factor for improved outcome in patients with melanoma treated with PEG-IFN.