Phase II evaluation of recombinant interferon alpha and BCNU in recurrent glioma

The Use of Targeted Cytokines as Cancer Therapeutics in Glioblastoma

Cytokines play an important role in regulating the immune response. Although there is great interest in exploiting cytokines for cancer immunotherapy, their clinical potential is limited by their pleiotropic properties and instability. A variety of cancer cell-intrinsic and extrinsic characteristics pose a barrier to effective treatments including cytokines. Recent studies using gene and cell therapy offer new opportunities for targeting cytokines or their receptors, demonstrating that they are actionable targets. Current efforts such as virotherapy, systemic cytokine therapy, and cellular and gene therapy have provided novel strategies that incorporate cytokines as potential therapeutic strategies for glioblastoma. Ongoing research on characterizing the tumor microenvironment will be informative for prioritization and combinatorial strategies of cytokines for future clinical trials. Unique therapeutic opportunities exist at the convergence of cytokines that play a dual role in tumorigenesis and immune modulation. Here, we discuss the underlying strategies in pre- and clinical trials aiming to enhance treatment outcomes in glioblastoma patients.

Adjuvant Temozolomide Chemotherapy With or Without Interferon Alfa Among Patients With Newly Diagnosed High-grade Gliomas: A Randomized Clinical Trial

IMPORTANCE

High-grade gliomas (HGGs) constitute the most common and aggressive primary brain tumor, with 5-year survival rates of 30.9% for grade 3 gliomas and 6.6% for grade 4 gliomas. The add-on efficacy of interferon alfa is unclear for the treatment of HGG.

OBJECTIVES

To compare the therapeutic efficacy and toxic effects of the combination of temozolomide and interferon alfa and temozolomide alone in patients with newly diagnosed HGG.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter, randomized, phase 3 clinical trial enrolled 199 patients with newly diagnosed HGG from May 1, 2012, to March 30, 2016, at 15 Chinese medical centers. Follow-up was completed July 31, 2021, and data were analyzed from September 13 to November 24, 2021. Eligible patients were aged 18 to 75 years with newly diagnosed and histologically confirmed HGG and had received no prior chemotherapy, radiotherapy, or immunotherapy for their HGG.

INTERVENTIONS

All patients received standard radiotherapy concurrent with temozolomide. After a 4-week break, patients in the temozolomide with interferon alfa group received standard temozolomide combined with interferon alfa every 28 days. Patients in the temozolomide group received standard temozolomide.

MAIN OUTCOMES AND MEASURES

The primary end point was 2-year overall survival (OS). Secondary end points were 2-year progression-free survival (PFS) and treatment tolerability.

RESULTS

A total of 199 patients with HGG were enrolled, with a median follow-up time of 66.0 (95% CI, 59.1-72.9) months. Seventy-nine patients (39.7%) were women and 120 (60.3%) were men, with ages ranging from 18 to 75 years and a median age of 46.9 (95% CI, 45.3-48.7) years. The median OS of patients in the temozolomide plus interferon alfa group (26.7 [95% CI, 21.6-31.7] months) was significantly longer than that in the standard group (18.8 [95% CI, 16.9-20.7] months; hazard ratio [HR], 0.64 [95% CI, 0.47-0.88]; P = .005). Temozolomide plus interferon alfa also significantly improved median OS in patients with O6-methylguanine-DNA methyltransferase (MGMT) unmethylation (24.7 [95% CI, 20.5-28.8] months) compared with temozolomide (17.4 [95% CI, 14.1-20.7] months; HR, 0.57 [95% CI, 0.37-0.87]; P = .008). Seizure and influenzalike symptoms were more common in the temozolomide plus interferon alfa group, with 2 of 100 (2.0%) and 5 of 100 (5.0%) patients with grades 1 and 2 toxic effects, respectively (P = .02). Finally, results suggested that methylation level at the IFNAR1/2 promoter was a marker of sensitivity to temozolomide plus interferon alfa.

CONCLUSIONS AND RELEVANCE

Compared with the standard regimen, temozolomide plus interferon alfa treatment could prolong the survival time of patients with HGG, especially the MGMT promoter unmethylation variant, and the toxic effects remained tolerable.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01765088.

Combining Radiation Therapy With Interferons: Back to the Future

Radiation therapy has been linked to the induction of an intratumoral type I interferon (IFN) response, which positively affects the response to treatment. This has spiked the interest to combine radiation therapy with IFN-based treatment. Interestingly, this combination treatment has been considered previously, since preclinical studies demonstrated a radiosensitizing effect of interferons. As a result, multiple clinical trials have been performed combining radiation therapy with interferons in different tumor types. Although potential benefit has been suggested, the outcomes of the trials are diverse and challenging to interpret. In addition, increased grade ≥3 toxicity frequently resulted in a negative recommendation regarding the combination therapy. The latter appears premature because many studies were small and several aspects of the combination treatment have not yet been sufficiently explored to justify such a definite conclusion. This review summarizes the available literature on this combination therapy, with a focus on IFN-α and IFN-β. Based on preclinical studies and clinical trials, we evaluated the potential opportunities and describe the current challenges. In addition, we identify several issues that should be addressed to fully exploit the potential benefit of this combinatorial treatment approach.

HeberFERON, a new formulation of IFNs with improved pharmacodynamics: Perspective for cancer treatment

The rational combination of recombinant IFN-α2b and IFN-γ resulted in a new formulation of interferons (HeberFERON) with improved pharmacodynamics. In basal cell carcinomas HeberFERON produces a more rapid antitumor effect and results in a larger number of complete responses. In patients with glioblastoma multiforme, the administration of HeberFERON after surgery and radiotherapy results in an estimated overall survival of 19 months. Patients with stage III or IV renal cell carcinoma also appear to benefit from the intravenous administration of HeberFERON, with prolongation of survival and good quality of live. HeberFERON offers a promising alternative formulation of interferons for the treatment of cancer with a very favorable safety profile.

Procarbazine, lomustine and vincristine for recurrent high-grade glioma

BACKGROUND

Recurrent high-grade glioma (HGG) carries an extremely poor prognosis. There is no current standard of care or guideline-based recommendations. Nitrosourea-based multidrug chemotherapy or PCV - procarbazine, lomustine (CCNU) and vincristine - is one of the treatment options at recurrence. There has been no meta-analysis which looks at the benefits and harms of PCV chemotherapy in adults with recurrent HGG.

OBJECTIVES

To assess the effectiveness and safety of procarbazine, lomustine, and vincristine (PCV) chemotherapy with other interventions in adults with recurrent high-grade glioma. To investigate whether predefined subgroups of people benefit more or less from chemotherapy.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL Issue 4, 2017), MEDLINE (1946 to 22 May 2017), and Embase (1980 to 22 May 2017). We searched trial registries including the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP; apps.who.int/trialsearch) and the National Institutes of Health (NIH; ClinicalTrials.gov). We searched the reference lists of all identified studies; the electronic table of contents of the Journal of Neuro-Oncology (1983 to 2016) and Neuro-Oncology (1999 to 2016); and conference abstracts from the Society for Neuro-Oncology (SNO) and the American Society of Clinical Oncology (ASCO 2004 to 2016). We also searched unpublished grey literature and other regional databases. There were no language restrictions.

SELECTION CRITERIA

Randomised controlled trials (RCTs), quasi-randomised trials (QRCTs), or controlled clinical trials (CCTs) where PCV was used to treat adults with recurrent HGG. Comparison arm included no chemotherapy, other second line chemotherapy or best supportive care.

DATA COLLECTION AND ANALYSIS

Two review authors extracted the data and undertook a 'Risk of bias' assessment and critical appraisal of the studies.

MAIN RESULTS

We identified two RCTs meeting our inclusion criteria. The two trials tested different comparisons.One RCT included 35 participants and compared PCV with 'eight drugs in one day' multidrug chemotherapy, which is a combination of drugs with different mechanisms of action. Median survival was 6 months for the PCV group and 6.5 months for the 'eight drugs in one day' group. Adverse event outcomes were not graded or quantified. Progression-free survival (PFS) and quality of life (QoL) were not described in the methods and were not an outcome of interest. The sample size in this study was small, which lead to insufficient statistical power to detect clinical differences. According to the GRADE approach we judged the quality of evidence to be low for survival outcome and very low for chemotherapy toxicityThe second multi-institutional RCT included 447 participants and compared PCV with Temozolomide (TMZ). Participants were randomised into three arms to receive PCV, and two different regimens of TMZ in a 2:1:1 ratio at first recurrence. The trial reported a median overall survival of 6.7 months and 7.2 months for the PCV and TMZ group respectively. It reported a PFS of 3.6 months for the PCV group and 4.7 months for the TMZ group. There was no observed difference of effect on overall survival (hazard ratio (HR) 0.91, 95% CI 0.74 to 1.11; P = 0.35) or PFS (HR 0.89, 95% CI 0.73 to 1.08; P = 0.23) in participants receiving PCV or TMZ chemotherapy. The proportion of people with at least one grade 3 or 4 adverse event was not clinically important at 9.2% versus 12.2% in PCV and TMZ arms respectively. Mean QoL scores calculated at baseline, 12 weeks and 24 weeks was 51.9 versus 59.8 favouring TMZ (P = 0.04) which is statistically but not clinically significant and was less than the pre-defined 10 point change for moderate improvement. We judged the GRADE quality of evidence to be moderate for overall survival, PFS, and chemotherapy toxicity and low for QoL.

AUTHORS' CONCLUSIONS

Evidence is based on a single large trial analysis as the other trial was small, with inadequate power to detect survival difference. Chemotherapy-naive patients with HGG at first recurrence when treated with PCV or TMZ have similar survival and time-to-progression outcomes. Adverse events are similar and QoL scores are statistically but not clinically significant between TMZ and PCV. Further RCTs should be conducted with adequate power following CONSORT guidelines with emphasis on QoL outcomes.

Immunological Aspects of Malignant Gliomas

Glioblastoma Multiforme (GBM) is the most common malignant primary brain neoplasm having a mean survival time of <24 months. This figure remains constant, despite significant progress in medical research and treatment. The lack of an efficient anti-tumor immune response and the micro-invasive nature of the glioma malignant cells have been explained by a multitude of immune-suppressive mechanisms, proven in different models. These immune-resistant capabilities of the tumor result in a complex interplay this tumor shares with the immune system. We present a short review on the immunology of GBM, discussing the different unique pathological and molecular features of GBM, current treatment modalities, the principles of cancer immunotherapy and the link between GBM and melanoma. Current knowledge on immunological features of GBM, as well as immunotherapy past and current clinical trials, is discussed in an attempt to broadly present the complex and formidable challenges posed by GBM.

Radiation plus Procarbazine, CCNU, and Vincristine in Low-Grade Glioma

BACKGROUND

Grade 2 gliomas occur most commonly in young adults and cause progressive neurologic deterioration and premature death. Early results of this trial showed that treatment with procarbazine, lomustine (also called CCNU), and vincristine after radiation therapy at the time of initial diagnosis resulted in longer progression-free survival, but not overall survival, than radiation therapy alone. We now report the long-term results.

METHODS

We included patients with grade 2 astrocytoma, oligoastrocytoma, or oligodendroglioma who were younger than 40 years of age and had undergone subtotal resection or biopsy or who were 40 years of age or older and had undergone biopsy or resection of any of the tumor. Patients were stratified according to age, histologic findings, Karnofsky performance-status score, and presence or absence of contrast enhancement on preoperative images. Patients were randomly assigned to radiation therapy alone or to radiation therapy followed by six cycles of combination chemotherapy.

RESULTS

A total of 251 eligible patients were enrolled from 1998 through 2002. The median follow-up was 11.9 years; 55% of the patients died. Patients who received radiation therapy plus chemotherapy had longer median overall survival than did those who received radiation therapy alone (13.3 vs. 7.8 years; hazard ratio for death, 0.59; P=0.003). The rate of progression-free survival at 10 years was 51% in the group that received radiation therapy plus chemotherapy versus 21% in the group that received radiation therapy alone; the corresponding rates of overall survival at 10 years were 60% and 40%. A Cox model identified receipt of radiation therapy plus chemotherapy and histologic findings of oligodendroglioma as favorable prognostic variables for both progression-free and overall survival.

CONCLUSIONS

In a cohort of patients with grade 2 glioma who were younger than 40 years of age and had undergone subtotal tumor resection or who were 40 years of age or older, progression-free survival and overall survival were longer among those who received combination chemotherapy in addition to radiation therapy than among those who received radiation therapy alone. (Funded by the National Cancer Institute and others; ClinicalTrials.gov number, NCT00003375.).

Recent developments on immunotherapy for brain cancer

INTRODUCTION

Brain tumors are a unique class of cancers since they are anatomically shielded from normal immunosurveillance by the blood-brain barrier, lack a normal lymphatic drainage system and reside in a potently immunosuppressive environment. Of the primary brain cancers, glioblastoma multiforme (GBM) is the most common and aggressive in adults. Although treatment options include surgery, radiation and chemotherapy, the average lifespan of GBM patients remains at only 14.6 months post-diagnosis.

AREAS COVERED

A review of key cellular and molecular immune system mediators in the context of brain tumors including TGF-β, cytotoxic T cells, Tregs, CTLA-4, PD-1 and IDO is discussed. In addition, prognostic factors, currently utilized immunotherapeutic strategies, ongoing clinical trials and a discussion of new or potential immunotherapies for brain tumor patients are considered.

EXPERT OPINION

Current drugs that improve the quality of life and overall survival in patients with brain tumors, especially for GBM, are poorly effective. This disease requires a reanalysis of currently accepted treatment strategies, as well as newly designed approaches. Here, we review the fundamental aspects of immunosuppression in brain tumors, new and promising immunotherapeutic drugs as well as combinatorial strategies that focus on the simultaneous inhibition of immunosuppressive hubs, both in immune and brain tumor cells, which is critical to consider for achieving future success for the treatment of this devastating disease.

Challenges in immunotherapy presented by the glioblastoma multiforme microenvironment

Glioblastoma multiforme (GBM) is the most common and aggressive primary brain tumor in adults. Despite intensive treatment, the prognosis for patients with GBM remains grim with a median survival of only 14.6 months. Immunotherapy has emerged as a promising approach for treating many cancers and affords the advantages of cellular-level specificity and the potential to generate durable immune surveillance. The complexity of the tumor microenvironment poses a significant challenge to the development of immunotherapy for GBM, as multiple signaling pathways, cytokines, and cell types are intricately coordinated to generate an immunosuppressive milieu. The development of new immunotherapy approaches frequently uncovers new mechanisms of tumor-mediated immunosuppression. In this review, we discuss many of the current approaches to immunotherapy and focus on the challenges presented by the tumor microenvironment.

Earlier detection of tumor treatment response using magnetic resonance diffusion imaging with oscillating gradients

An improved method for detecting early changes in tumors in response to treatment, based on a modification of diffusion-weighted magnetic resonance imaging, has been demonstrated in an animal model. Early detection of therapeutic response in tumors is important both clinically and in pre-clinical assessments of novel treatments. Noninvasive imaging methods that can detect and assess tumor response early in the course of treatment, and before frank changes in tumor morphology are evident, are of considerable interest as potential biomarkers of treatment efficacy. Diffusion-weighted magnetic resonance imaging is sensitive to changes in water diffusion rates in tissues that result from structural variations in the local cellular environment, but conventional methods mainly reflect changes in tissue cellularity and do not convey information specific to microstructural variations at sub-cellular scales. We implemented a modified imaging technique using oscillating gradients of the magnetic field for evaluating water diffusion rates over very short spatial scales that are more specific for detecting changes in intracellular structure that may precede changes in cellularity. Results from a study of orthotopic 9L gliomas in rat brains indicate that this method can detect changes as early as 24 h following treatment with 1,3-bis(2-chloroethyl)-1-nitrosourea, when conventional approaches do not find significant effects. These studies suggest that diffusion imaging using oscillating gradients may be used to obtain an earlier indication of treatment efficacy than previous magnetic resonance imaging methods.

Temozolomide Versus Procarbazine, Lomustine, and Vincristine in Recurrent High-Grade Glioma

Purpose

Temozolomide (TMZ) is an alkylating agent licensed for treatment of high-grade glioma (HGG). No prospective comparison with nitrosourea-based chemotherapy exists. We report, to our knowledge, the first randomized trial of procarbazine, lomustine, and vincristine (PCV) versus TMZ in chemotherapy-naive patients with recurrent HGG.

Patients and Methods

Four hundred forty-seven patients were randomly assigned to PCV (224 patients) or TMZ (sub–random assignment: TMZ-5 [200 mg/m2 for 5 days, 112 patients] or TMZ-21 [100 mg/m2 for 21 days, 111 patients]) for up to 9 months or until progression. The primary outcomes were survival (PCV v TMZ) and 12-week progression-free survival (PFS; TMZ-5 v TMZ-21). This study is registered as ISRCTN83176944.

Results

Percentages of patients completing 9 months of treatment in the PCV, TMZ-5, and TMZ-21 arms were 17%, 26%, and 13%, respectively. Major toxicity was similar across all three groups. With a median follow-up time of 12 months and 382 deaths, there was no clear survival benefit when comparing PCV with TMZ (hazard ratio [HR], 0.91; 95% CI, 0.74 to 1.11; P = .350). For TMZ-5 versus TMZ-21, 12-week PFS rates were similar (63.6% and 65.7%, respectively; P = .745), but TMZ-5 improved overall PFS (HR, 1.38; 95% CI, 1.05 to 1.82; P = .023), survival (HR, 1.32; 95% CI, 0.99 to 1.75; P = .056), and global quality of life (49% v 19% improved > 10 points at 6 months, respectively; P = .005).

Conclusion

Although TMZ (both arms combined) did not show a clear benefit compared with PCV, comparison of the TMZ schedules demonstrated that the 21-day schedule was inferior to the 5-day schedule in this setting. This challenges the current understanding of increasing TMZ dose-intensity by prolonged scheduling.

Is there a place for radiotherapy in low-grade gliomas?

The optimal management of supratentorial low-grade glioma remains controversial, and only limited definitive data is available to guide recommendations. Treatment decisions have to take into account both the management of symptoms and of tumour control, and must balance the benefits against the potential for treatment-related complications. Overall outcome is more dependent on patient and tumour-related characteristics such as age, tumour grade, histology and neurological function than treatment. From the pooled analysis of 2 randomized EORTC trials a prognostic score has been derived, median survival is varying from 3.2 to 7.8 years. Radiation therapy is usually the primary treatment modality; however its benefit on initial tumour control may be outweighed by potential late toxicity. To date only 4 large randomized trials in patients with low-grade glioma have been reported. It allows concluding that early radiotherapy does not improve overall survival and supports an initially expectative approach. Similarly, higher radiation doses above 45-50 Gy (fractions of 1.8-2.0 Gy) do not confer a better outcome but may be associated with increased toxicity. The adjuvant use of PCV-chemotherapy in high-risk patients also failed to improve progression-free and overall survival. An ongoing large randomized EORTC/NCIC trial is investigating the primary treatment with temozolomide chemotherapy versus standard radiotherapy in patients "at need for treatment". Tumour material will be collected in all patients, which ultimately may allow identifying on a molecular basis patients for whom one or another treatment strategy may fit best. Irrespective of new chemotherapeutic agents, radiotherapy is also evolving. Highly conformal techniques based on modern imaging as co-registered MRI scans, limiting the amount of normal tissue irradiated without compromising tumour control, will be the future approach in order to reduce neurotoxicity.

Immunostimulants for malignant gliomas

Several immunostimulant approaches have been studied in the treatment of gliomas. The advent of recombinant DNA technology led to a nonspecific immunostimulation via systemic administration of cytokines. Recently, in attempts to more closely mimic their natural activity, cytokines have been delivered by implanting genetically transduced cells or by using in vivo gene transfer techniques. The latest efforts have focused on immunostimulatory agents that act directly on antigen-presenting cells and effector cells of the immune system via pattern recognition receptors. Combining these strategies with more than one mode of immunotherapy may provide better clinical results.

Challenges in clinical design of immunotherapy trials for malignant glioma

Glioblastoma multiforme (GBM) is the most common and lethal primary malignant brain tumor. The traditional treatments for GBM, including surgery, radiation, and chemotherapy, only modestly improve patient survival. Therefore, immunotherapy has emerged as a novel therapeutic modality. Immunotherapeutic strategies exploit the immune system's ability to recognize and mount a specific response against tumor cells, but not normal cells. Current immunotherapeutic approaches for glioma can be divided into 3 categories: immune priming (active immunotherapy), immunomodulation (passive immunotherapy), and adoptive immunotherapy. Immune priming sensitizes the patient's immune cells to tumor antigens using various vaccination protocols. In the case of immunomodulation, strategies are aimed at reducing suppressive cytokines in the tumor microenvironment or using immune molecules to specifically target tumor cells. Adoptive immunotherapy involves harvesting the patient's immune cells, followed by ex vivo activation and expansion before reinfusion. This article provides an overview of the interactions between the central nervous system and the immune system, and discusses the challenges facing current immunotherapeutic strategies.

Two phase II trials of temozolomide with interferon-alpha2b (pegylated and non-pegylated) in patients with recurrent glioblastoma multiforme

BACKGROUND

Because of the poor outcomes for patients with recurrent glioblastoma multiforme (GBM), and some laboratory and clinical evidence of efficacy using interferon in GBM, we assessed the toxicity and efficacy of temozolomide (TMZ) combined with either short-acting (IFN) or long-acting (pegylated) interferon alpha2b (PEG) in two single-arm phase II studies, and compared the results to 6-month progression-free survival (PFS-6) data from historical controls.

METHODS

Two single-arm phase II studies were carried out in adults with GBM. Patients were treated with the standard regimen of TMZ (150-200 mg m(-2) per day x 5 days every month) combined with either 4 million units per m(2) subcutaneously (SQ) three times weekly of IFN or 0.5 microg kg(-1) SQ weekly of PEG. Physical exams and imaging evaluations were carried out every 8 weeks.

RESULTS

On the IFN study, 34 adults (74% men) were enrolled, and 29 adults (55% men) on the PEG study; median Karnofsky performance status was 80 and 90 for the IFN and PEG studies, respectively. Grade 3 or 4 toxicities were common, leucopoenia and thrombocytopoenia occurring in 35-38% and 18-21% of patients, respectively. Grade 3 or 4 fatigue occurred in 18% of patients on both studies. Lymphopoenia was infrequent. PFS-6 was 31% for 29 evaluable patients in the IFN study and 38% for 26 evaluable patients in the PEG study.

CONCLUSION

In recurrent GBM patients, both studies of standard dose TMZ with either IFN or PEG showed improved efficacy when compared to historical controls, or reports using TMZ alone. Even though the TMZ+PEG study met criteria for further study, the results of both of these studies must be considered in light of the standard of care (TMZ plus radiotherapy) for newly diagnosed GBM, which has evolved since the inception of these studies. Despite the results of the current studies being eclipsed by the new GBM standard of care, these results can still inform the development of newer approaches for GBM, either in an earlier, upfront setting, or by extrapolation of the results and consideration of the use of PEG or IFN in conjunction with other antiglioma strategies.

Recent progress in immunotherapy for malignant glioma: treatment strategies and results from clinical trials

BACKGROUND

Despite advances in surgical and adjuvant radiation therapy and chemotherapy strategies, malignant gliomas continue to be associated with poor prognoses.

METHODS

We review immune-mediated treatment approaches for malignant glioma and the relevance of recent clinical trials and their outcomes. We specifically address the increasing evidence implicating the role of cytotoxic T cells in ensuring adequate immune-mediated clearance of neoplastic cells and the need for the optimization of therapies that can elicit and support such antitumor T-cell activity.

RESULTS

The poor outcome of this disease has spurred the search for novel experimental therapies that can address and overcome the root biological phenomena associated with the lethality of this disease. The use of immunotherapy to bolster the otherwise impaired antitumor immune responses in glioma patients has received increasing attention.

CONCLUSIONS

An effective treatment paradigm for malignant gliomas may eventually require a multifaceted approach combining two or more different immunotherapeutic strategies. Such scenarios may involve the use of local cytokine gene therapy to enhance glioma-cell immunogenicity in conjunction with dendritic cell-based active vaccination to stimulate systemic tumoricidal T-cell immunity. Given the heterogeneity of this disease process and the potential risk of immunoediting out a selected, treatment-refractory tumor cell population, the concurrent use of multiple modalities that target disparate tumor characteristics may be of greatest therapeutic relevance.

The relationship between six-month progression-free survival and 12-month overall survival end points for phase II trials in patients with glioblastoma multiforme

Common end points for phase II trials in patients with glioblastoma multiforme (GBM) are six-month progression-free survival (PFS6) and 12-month overall survival (OS12). OS12 can be accurately measured but may be confounded with subsequent therapies upon progression, whereas the converse is true for PFS6. Our goal was to assess the relationship between these end points separately for phase II trials in patients with newly diagnosed GBM and patients with recurrent GBM. Data were pooled from 11 North Central Cancer Treatment Group trials for patients with newly diagnosed GBM (n = 1348). All patients received radiotherapy and pharmaceutical therapy (before, during, or after radiotherapy). Data were pooled from 16 trials that used various pharmaceuticals in treating patients for recurrent GBM (n = 345). All trial regimens were declared nonefficacious by predefined criteria. Overall per-patient concordance was estimated with a kappa statistic. The relationship between OS12 and PFS6 across study arms was assessed by weighted linear regression and Pearson's correlation. Simulation was used to determine the agreement of study outcomes when using PFS6 versus OS12 end points. Cox models with progression status as a time-dependent variable and Kaplan-Meier estimators were used to ascertain the association between progression-free survival status and overall survival. At present, 97% of the patients with newly diagnosed GBM and 95% of those with recurrent GBM have died. The PFS6 and OS12 were 43% and 41%, respectively, for patients with newly diagnosed disease and 9% and 14% for patients with recurrent disease. There was only moderate concordance between the end points on both the patient level and the study level. For the simulation studies, we established phase II efficacy criteria for each end point by using the pooled estimates of OS12 (PFS6) as historical controls. The study decisions made using PFS6 and OS12 were in agreement 88% and 90% of the time for the trials of newly diagnosed and recurrent disease, respectively. Finally, there was a strong association between progression-free survival status and overall survival. PFS6 seems to be a reasonable end point for phase II trials in patients with recurrent glioblastoma.

Angiogenesis in malignant glioma--a target for antitumor therapy?

The prognosis of malignant gliomas is still dismal despite aggressive treatment attempts. Thus, alternative therapy strategies are needed. Malignant gliomas are upon the best vascularized tumors in humans and their proliferation is hallmarked by a distinct proliferative vascular component. Hence it seems to be a logical consequence to apply anti-angiogenic treatment strategies to malignant gliomas. These treatment strategies have shown promising effects in animal models and some experimental clinical studies. This review gives a short introduction into the molecules involved in angiogenesis of malignant gliomas, it provides an overview of the latest experimental developments of glioma angiogenesis inhibition and discusses the results of clinical anti-angiogenic trials in patients with high grade glioma. Additionally the problem of monitoring the treatment success of an anti-angiogenic therapy is addressed.

Therapy for recurrent malignant glioma in adults

Malignant gliomas are the most common form of primary brain tumors in adults. Although the prognosis remains poor, there has been recent progress in the treatment of these tumors. Standard therapy for patients with this disease will be reviewed, together with more novel approaches such as targeted molecular therapies, angiogenesis inhibitors, immunotherapies, gene therapies and intratumoral therapies.

Phase II trial of procarbazine, lomustine, and vincristine as initial therapy for patients with low-grade oligodendroglioma or oligoastrocytoma: efficacy and associations with chromosomal abnormalities

PURPOSE

The purpose of this article is to determine the response rate and toxicity of PCV administered before radiation therapy in patients with newly diagnosed LGO/LGOA and to explore correlations between response with 1p/19q deletions and aberrant p53 expression.

BACKGROUND

Despite prolonged survival of patients with low-grade oligodendroglioma (LGO) and oligoastrocytoma (LGOA), the majority will succumb to progressive disease. Because procarbazine, lomustine (CCNU), and vincristine (PCV) is active in patients with recurrent LGO/LGOA, we hypothesized that it would be beneficial as primary therapy.

METHODS

Adult patients with residual tumor on magnetic resonance imaging scan following biopsy or subtotal resection of LGO/LGOA received up to six cycles of PCV. Radiation therapy (59.4 or 54.0 Gy) began within 10 weeks of completing chemotherapy or immediately if there was evidence of tumor progression on PCV. Tumor tissue was analyzed by fluorescent in situ hybridization for 1p and 19q deletion and by immunohistochemistry for p53 expression.

RESULTS

Eight of 28 (29%) and 13 of 25 (52%) eligible patients demonstrated tumor regression as assessed by the treating physician and a blinded central neuroradiology reviewer, respectively. Myelosuppression was the predominant toxicity. Loss of 1p and 19q were associated with LGO but not LGOA (P =.009), were inversely associated with p53 detection, and were not associated with response to PCV (possibly because of the small sample size).

CONCLUSION

PCV produces tumor regressions in a meaningful proportion of patients with LGO/LGOA. Toxicity, especially myelosuppression, is significant. Loss of 1p and 19q seems limited to patients with pure LGO and is inversely related to p53 alterations.

Anti-angiogenic agents for the treatment of brain tumors

It is accepted that novel therapeutic approaches are needed for the majority of patients with malignant brain tumors. The vascularity of many primary brain tumors and the encouraging preclinical studies suggest that antiangiogenic agents have the potential to become an important component of multimodality treatment of patients with brain tumors. The understanding of the biology of angiogenesis is improving rapidly, offering the hope for more specific vascular targeting of brain tumor neovasculature. Neuroimaging techniques evaluating the angiogenic process and the impact of antiangiogenic agents will be an important tool for the rapid development of these novel therapeutic agents.

Non-cytotoxic therapies for malignant gliomas

Malignant gliomas cause 2% of cancer deaths in western countries, and even the most intensive combinations of radiotherapy and chemotherapy cannot be curative. New chemotherapeutic drugs and alternative therapeutic modalities are strongly needed. Huge efforts are directed towards the development of innovative strategies for targeting and mending the specific molecular alterations in tumor cells (translational research). This review aims to summarize the most promising lines of investigational research in the field of neuro-oncology, such as non-cytotoxic drugs, immunotoxins, inhibitors of angiogenesis and gene therapy approaches, which will probably offer new therapy options for brain tumor patients.

A phase III study of radiation therapy plus carmustine with or without recombinant interferon-alpha in the treatment of patients with newly diagnosed high-grade glioma

BACKGROUND

The current study was conducted to determine whether the addition of interferon-alpha (IFN-alpha) to treatment with radiation therapy and carmustine (BCNU) improves time to disease progression or overall survival in patients with high-grade glioma.

METHODS

Patients with anaplastic astrocytoma, anaplastic oligoastrocytoma, glioblastoma multiforme, or gliosarcoma received radiation therapy plus BCNU as initial therapy. Subsequently, patients without tumor progression at the completion of radiation therapy were stratified by age, extent of surgery, tumor grade and histology, Eastern Cooperative Oncology Group performance status, and treating institution, and then were randomly assigned to receive either BCNU alone (200 mg/m(2) on Day 1) or BCNU (150 mg/m(2) on Day 3) plus IFN--alpha (12 million U/m(2) on Days 1-3, Weeks 1, 3, and 5) every 7 weeks for a maximum of 6 cycles.

RESULTS

Of the 383 patients enrolled in the study, 275 eligible patients were randomized. There was no significant difference with regard to time to disease progression or overall survival between the two groups. Patients receiving IFN-alpha experienced more fever, chills, myalgias, and neurocortical symptoms including somnolence, confusion, and exacerbation of neurologic deficits. Cox multivariate regression models confirmed known favorable prognostic variables including younger age, Grade 3 tumor (according to World Health Organization criteria), and greater extent of surgery. Cox and classification and regression tree analysis models also demonstrated that a normal baseline Folstein mini-mental status examination (MMSE) score was associated with better prognosis.

CONCLUSIONS

IFN-alpha does not appear to improve time to disease progression or overall survival in patients with high-grade glioma and appears to add significantly to toxicity. The baseline MMSE score may serve as an independent prognostic factor and warrants further investigation.

Chemotherapy of low-grade gliomas

Histologic subtypes of low-grade gliomas include pilocytic astrocytomas (World Health Organization [WHO] grade I), diffuse infiltrating astrocytomas, oligodendrogliomas, and mixed oligo-astrocytomas (WHO grade II). Although extended survival is typical with these tumors, most patients eventually succumb to recurrent or progressive disease despite receiving either adjuvant radiation therapy or radiation at the time of recurrence. Not surprisingly, chemotherapy for low-grade gliomas has primarily been evaluated in the salvage setting of postradiotherapy progression in both adults and children. Unfortunately, the published body of literature describing chemotherapy for these tumors is small and subject to a number of confounding methodologic limitations. Nonetheless, some guidelines for the use of chemotherapy in these patients can be inferred from the published experience. The data reviewed clearly identifies a potential benefit for PCV chemotherapy (procarbazine, CCNU, and vincristine) in at least a subset of patients with low-grade oligodendroglial tumors. Nitrosoureas and platinum agents appear to have modest efficacy in recurrent oligodendroglial tumors and in some patients with newly diagnosed or progressive low-grade astrocytomas; however, surgery and radiation remain the primary treatment modalities for this group of malignancies. Until new data becomes available, chemotherapy still should be used only as a salvage option in previously irradiated patients with recurrent or progressive low-grade gliomas.

Brain tumors in the older person

BACKGROUND

The incidence of brain tumors is increasing rapidly, particularly in the older population. Advances in molecular biology help to explain differences in biologic behavior and response to therapy of brain tumors in the elderly compared with younger patients. The number of elderly patients who desire and receive therapy for brain tumors and are included in clinical trials is increasing.

METHODS

This article reviews the literature on the epidemiology, clinical aspects, and therapy of brain tumors, with emphasis on the older patient population.

RESULTS

The increased incidence of brain tumors in the elderly is principally due to the increasing number of people who comprise the older population. Age and performance status are important independent prognostic indicators, together with tumor histology. Surgery, radiation therapy, and chemotherapy can benefit elderly patients with brain tumors with favorable histologies, tumor location, and good performance status. The response rates to available therapies are less favorable than in younger patients, and only a small number of elderly patients are enrolled in clinical studies addressing new treatment modalities.

CONCLUSIONS

Brain tumors in the elderly have specific characteristics that determine their biologic behavior and response to therapy. There is a need for clinical studies designed for treatment of brain tumors in older patients, and requirements for rehabilitation and support systems for the elderly need to be addressed.

A randomized phase II and pharmacokinetic study of dacarbazine in patients with recurrent glioma

We conducted a randomized phase II study to determine the efficacy of dacarbazine (DTIC) in recurrent gliomas. Patients were randomly assigned to receive either DTIC 750 mg/m2 IV day 1 every 28 days (Arm A) or DTIC 200 mg/m2 IV days 1-5 every 28 days (Arm B). Pharmacokinetics were studied in 6 patients on each arm using HPLC analysis. Thirty-nine patients (30 male, 9 female), ages 27-67 years (median 53) were entered on the study (20 on Arm A, 19 on Arm B). No objective responses were seen. Median time to progression was 3 months. Median survival was 8 months. Treatment was generally well tolerated. Major toxicities were grade 1-2 nausea (33%). lethargy (28%), diarrhea (15%), alopecia (15%), and grade 3 neutropenia (8%). Four patients on Arm A had mild self-limited episodes of intravascular hemolysis occurring immediately after drug infusion, the mechanism of which is unknown. Mean AUC for DTIC, HMMTIC (5-[3-hydroxymethyl-3-methyl-1-triazeno] imidazole-4-carboxamide), and MTIC (5-[3-methyl-1-triazenol imidazole-4-carboxamide), in Arm A were 14.8, 0.17, and 1.15 mM min, respectively. Corresponding values for Arm B (on day 1 of 5) were 1.7, 0.06, and 0.29 mM min, respectively. The predicted HMMTIC and MTIC exposure over 5 days for Arm B, based on the day 1 data, is higher than with Arm A. We conclude that DTIC is well tolerated but does not have activity in patients with recurrent gliomas. The 5-day schedule appears less toxic, and pharmacokinetic studies show that it provides greater exposure to MTIC and HMMTIC compared to the one-day schedule.

Initial and maintenance combination treatment with interferon-beta, MCNU (Ranimustine), and radiotherapy for patients with previously untreated malignant glioma

Combined treatment with interferon-beta, MCNU (Ranimustine), and radiotherapy was assessed in patients with malignant glioma who had not received previous cytotoxic drug therapy. Forty-three patients up to 75 years old with histopathologically confirmed malignant glioma were studied. All patients had tumors measurable by neuroimaging, a Karnofsky performance score exceeding 40, and an expected survival exceeding 2 months. A response rate of 49% (21/45) was observed, including 6 complete remissions (14%) and 15 partial remissions (35%). Of the 43 patients who completed initial therapy, 19 were given sequential maintenance therapy. Survival time was much longer with than without maintenance therapy. Toxic side effects were moderate and did not substantially affect patients' general condition. We concluded that this combination therapy had a pronounced effect on untreated malignant glioma, particularly in patients whose initial therapy was followed up with maintenance therapy.

Multicenter phase II trial of temozolomide in patients with anaplastic astrocytoma or anaplastic oligoastrocytoma at first relapse. Temodal Brain Tumor Group

PURPOSE

To determine the antitumor efficacy and safety profile of temozolomide in patients with malignant astrocytoma at first relapse.

PATIENTS AND METHODS

This open-label, multicenter, phase II trial enrolled 162 patients (intent-to-treat [ITT] population). After central histologic review, 111 patients were confirmed to have had an anaplastic astrocytoma (AA) or anaplastic mixed oligoastrocytoma. Chemotherapy-naive patients were treated with temozolomide 200 mg/m(2)/d. Patients previously treated with chemotherapy received temozolomide 150 mg/m(2)/d; the dose could be increased to 200 mg/m(2)/d in the absence of grade 3/4 toxicity. Therapy was administered orally on the first 5 days of a 28-day cycle.

RESULTS

Progression-free survival (PFS) at 6 months, the primary protocol end point, was 46% (95% confidence interval, 38% to 54%). The median PFS was 5.4 months, and PFS at 12 months was 24%. The median overall survival was 13.6 months, and the 6- and 12-month survival rates were 75% and 56%, respectively. The objective response rate determined by independent central review of gadolinium-enhanced magnetic resonance imaging scans of the ITT population was 35% (8% complete response [CR], 27% partial response [PR]), with an additional 26% of patients with stable disease (SD). The median PFS for patients with SD was 4.4 months, with 33% progression-free at 6 months. Maintenance of progression-free status and objectively assessed response (CR/PR/SD) were both associated with health-related quality-of-life (HQL) benefits. Adverse events were mild to moderate, with hematologic side effects occurring in less than 10% of patients.

CONCLUSION

Temozolomide demonstrated good single-agent activity, an acceptable safety profile, and documented HQL benefits in patients with recurrent AA.

Phase II North Central Cancer Treatment Group study of 2-cholorodeoxyadenosine in patients with recurrent glioma

There is no standard treatment for patients with recurrent gliomas, and their prognosis remains poor. 2-Chlorodeoxyadenosine is a purine analogue that has significant activity in many low-grade lymphoproliferative disorders. The authors conducted a phase II study to determine the efficacy of 2-chlorodeoxyadenosine in patients with recurrent gliomas. Patients with a histologically confirmed primary brain tumor with evidence of progression after radiation therapy were eligible. Protocol treatment consisted of 2-chlorodeoxyadenosine 7.0 mg/m2 intravenously on days 1 through 5 every 28 days. For those with a history of prior nitrosourea therapy, the dose of 2-chlorodeoxyadenosine was reduced to 5.6 mg/m2 on days 1 through 5. Treatment was continued until progression or a maximum of 12 cycles. Fifteen patients with recurrent astrocytomas or oligoastrocytomas of all grades were entered in the study. Treatment was well tolerated. Major toxicities were myelosuppression and neurotoxicity. No responses were seen. The authors conclude that although 2-chlorodeoxyadenosine is well tolerated, no demonstrable activity in patients with recurrent gliomas was established.

Verotoxins inhibit the growth of and induce apoptosis in human astrocytoma cells

Verotoxin 1 (VT1) is an E. coli toxin comprising an A subunit with N-glycanase activity, and five smaller B subunits capable of binding to the functional receptor globotriaosylceramide (Galalpha1-4-Galbeta1-4-Glcceramide-Gb3). VT is implicated in hemorrhagic colitis and the more serious hemolytic uremic syndrome. VT1 is active against various tumor cell lines in vitro and in vivo. To extend the anti-cancer spectrum of activity of VT to human brain tumors, in the present analysis we studied the effects of VT on the growth of 6 permanent human astrocytoma cell lines. All astrocytoma cell lines analyzed express Gb3 and were sensitive to VT-1 at a dose of 50 ng/ml, but sensitivity was not proportional to the relative Gb3 concentration. VT induced apoptosis in these cells was shown by electron microscopy. Morphological evidence (nuclear shrinkage and chromatin condensation) of apoptosis could be clearly distinguished 1.5 hrs after toxin addition. Ultrastructural preservation of organelles was observed in conjunction with blebbing of the plasma membrane, condensation of chromatin within the nucleus and nuclear shrinkage. Apoptosis was also induced by the recombinant toxin B subunit alone, suggesting that the ligation of Gb3 is the primary induction mechanism. These studies indicate that verotoxin/Gb3 targetting may provide a novel basis for the inhibition of astrocytoma tumour cell growth.

Interferon-alpha enhances CD95L-induced apoptosis of human malignant glioma cells

CD95 ligand (CD95L)-induced apoptosis is a novel immunotherapeutic approach to malignant glioma. Here, we report that interferon-alpha (IFN-alpha) sensitizes LN-229 and T98G human malignant glioma cells to CD95L-induced apoptosis. In contrast to the effects of IFN-gamma and TNF-alpha which sensitize glioma cells to CD95 antibody-induced apoptosis in part by enhancing CD95 expression, IFN-alpha has no effect on CD95 expression at the cell surface of LN-229 and T98G cells. To confirm that changes in CD95 expression are not required for the effects of IFN-alpha, we show that IFN-alpha enhances CD95L-induced apoptosis even in CD95-transfected LN-308 glioma cells. These LN-308 cells have little endogenous CD95 expression but express high levels of CD95 from a stably integrated CD95 expression plasmid. The sensitizing effects of IFN-alpha appear to be independent of cell cycle effects of IFN-alpha and are unaffected by ectopic expression of the bcl-2 proto-oncogene. IFN-alpha enhances CD95L-induced activation of caspase-3, a critical mediator of CD95L-induced cell death. IFN-alpha also increases the cytotoxic effects of BCNU, teniposide and cytarabine in both cell lines, and of vincristine in LN-229 cells. Doxorubicin and 5-fluorouracil toxicity are unaffected by IFN-alpha. IFN-alpha may be a useful adjunct to novel strategies of immunochemotherapy for malignant gliomas that target CD95-mediated apoptosis.

MRI measurement of brain tumor response: comparison of visual metric and automatic segmentation

An automatic magnetic resonance imaging (MRI) multispectral segmentation method and a visual metric are compared for their effectiveness to measure tumor response to therapy. Automatic response measurements are important for multicenter clinical trials. A visual metric such as the product of the largest diameter and the largest perpendicular diameter of the tumor is a standard approach, and is currently used in the Radiation Treatment Oncology Group (RTOG) and the Eastern Cooperative Oncology Group (EGOG) clinical trials. In the standard approach, the tumor response is based on the percentage change in the visual metric and is categorized into cure, partial response, stable disease, or progression. Both visual and automatic methods are applied to six brain tumor cases (gliomas) of varying levels of segmentation difficulty. The analyzed data were serial multispectral MR images, collected using MR contrast enhancement. A fully automatic knowledge guided method (KG) was applied to the MRI multispectral data, while the visual metric was taken from the MRI films using the T1 gadolinium enhanced image, with repeat measurements done by two radiologists and two residents. Tumor measurements from both visual and automatic methods are compared to "ground truth," (GT) i.e., manually segmented tumor. The KG method was found to slightly overestimate tumor volume, but in a consistent manner, and the estimated tumor response compared very well to hand-drawn ground truth with a correlation coefficient of 0.96. In contrast, the visually estimated metric had a large variation between observers, particularly for difficult cases, where the tumor margins are not well delineated. The inter-observer variation for the measurement of the visual metric was only 16%, i.e., observers generally agreed on the lengths of the diameters. However, in 30% of the studied cases no consensus was found for the categorical tumor response measurement, indicating that the categories are very sensitive to variations in the diameter measurements. Moreover, the method failed to correctly identify the response in half of the cases. The data demonstrate that automatic 3D methods are clearly necessary for objective and clinically meaningful assessment of tumor volume in single or multicenter clinical trials.

Phase I evaluation of radiation combined with recombinant interferon alpha-2a and BCNU for patients with high-grade glioma

PURPOSE

A Phase I study to determine the safety, toxicity, and maximum tolerated dose (MTD) of carmustine (BCNU) and interferon alpha-2a (IFN-a) when combined with radiation as initial therapy in high-grade glioma.

METHODS AND MATERIALS

Patients with newly diagnosed Grade 3 or 4 astrocytoma, oligoastrocytoma, or gliosarcoma were enrolled after surgery. All received radiation therapy to the brain (64.8 Gy/36 fractions), combined with a single dose of BCNU (200 mg/m2) at the start of radiation. Chemotherapy after completing radiation consisted of BCNU 150 mg/m2 once every 7 weeks, and IFN-a 12 x 10(6) units/m2 subcutaneously Days 1-3 each week of a 7-week cycle. Subsequent dose modification was based on constitutional symptoms for IFN-a and on myelosuppression for BCNU.

RESULTS

Fifteen patients were entered on the study. Four were excluded because they did not receive IFN-a (3 refused treatment and 1 patient left the study due to multiple medical problems). Eleven were evaluable for toxicity and efficacy. Nonhematological toxicity, mainly lethargy and flu-like symptoms, were dose-limiting for IFN-a. After the first 6 patients were treated per the initial protocol, the frequency of IFN-a administration was decreased to Days 1-3 on weeks 1, 3, and 5 of the 7-week cycle for 5 additional patients. Lethargy, fever, chills, myalgias, alopecia, and anorexia occurred in all patients. Other toxicities included nausea and vomiting (91%), central-nervous-system depression or mood changes (64%), headaches (55%), and elevation of liver enzymes (36%). Grade 3-4 leukopenia occurred in 4 (45%) of 11 patients, and Grade 3-4 thrombocytopenia in 3 (27%) of 11 patients. Due to myelosuppressive effects, BCNU dose was not escalated. Median survival of the cohort was 44 months. Objective responses occurred in 5 (56%) of 9 patients and median duration of response was 33 months. The MTD of this combination after radiation therapy is IFN-a 12 x 10(6) units/m2 Days 1-3, on Weeks 1, 3, and 5 of a 7-week cycle and BCNU 150 mg/m2 Day 1, every 7 weeks.

CONCLUSIONS

Treatment with radiation, IFN-a, and BCNU is feasible and effective in patients with high-grade gliomas, although constitutional symptoms from IFN-a are substantial.

Phase II trial with BCNU plus alpha-interferon in patients with recurrent high-grade gliomas

A Phase II study with a combination of BCNU and alpha-interferon (IFN) was conducted in patients with high-grade glioma recurrent after surgery and radiation treatment in order to investigate tumor control and toxicity. Twenty-one non-chemotherapy pretreated patients were administered 6 MU alpha-IFN in a 2-h infusion followed by 150 mg/m2 BCNU i.v. on day 1. Three MU alpha-IFN were subsequently administered subcutaneously on alternating days three times a week, until recycling of the whole procedure on day 42. Among 21 patients, partial remission was obtained in 7 (33%; 95% CI = 15-57) and stable disease in 6 (29%; CI = 11-52); overall Kaplan-Meier median time to progression (TTP) was 4.5 months (CI = 4-9) and the overall median survival time (MST) was 7 months (CI = 5-13). In patients who underwent surgical redebulking prior to chemotherapy, TTP and MST were 9 (CI = 7-14) and 15 months (CI = 11.0-39.0); in patients who were not operated on again before chemotherapy, these values were 4 (CI = 2-5; log rank test, p = 0.0026) and 5.5 months (CI = 4-7; log rank test, p = 0.0012) respectively. The results of this regimen in relapsing patients, especially following surgical redebulking, are encouraging; toxicity is acceptable, and further studies on combined alpha-IFN and multiple-agent chemotherapy are warranted.

Cisplatin but not BCNU inhibits urokinase-type plasminogen activator levels in human glioblastoma cell lines in vitro

Glioblastomas extensively invade the surrounding normal brain tissue, with a concomitant expression of various proteolytic enzymes, in particular urokinase-type plasminogen activator (uPA). In this study we used cis-diamminedichloroplatinum (cisplatin) and 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), commonly used anti-cancer drugs for the treatment of glioblastomas, to study the expression of uPA in three human glioblastoma cell lines in vitro. Cells were treated with 25 microM cisplatin and 50 microM BCNU, and uPA levels were estimated by fibrin zymography during a 72-h time course. Treatment of glioblastoma cells with cisplatin resulted in significantly decreased levels of uPA in serum-free conditioned medium and cell extracts, compared to BCNU-treated and untreated cell lines. Quantitative levels of uPA enzyme activity assessed by scanning laser densitometry and uPA protein by ELISA using antibody against uPA showed decreased levels of uPA in cisplatin-treated glioma cell lines relative to BCNU and untreated cell lines. Our results suggest that anti-tumor compound, cisplatin, may exert its anti-neoplastic effects by inhibiting uPA in malignant glioblastomas.