Prolonged and severe thrombocytopenia with pancytopenia induced by radiation-combined temozolomide therapy in a patient with newly diagnosed glioblastoma--analysis of O6-methylguanine-DNA methyltransferase status

Polymer nanocarriers for targeted local delivery of agents in treating brain tumors

Glioblastoma (GBM), the deadliest brain cancer, presents a multitude of challenges to the development of new therapies. The standard of care has only changed marginally in the past 17 years, and few new chemotherapies have emerged to supplant or effectively combine with temozolomide. Concurrently, new technologies and techniques are being investigated to overcome the pharmacokinetic challenges associated with brain delivery, such as the blood brain barrier (BBB), tissue penetration, diffusion, and clearance in order to allow for potent agents to successful engage in tumor killing. Alternative delivery modalities such as focused ultrasound and convection enhanced delivery allow for the local disruption of the BBB, and the latter in particular has shown promise in achieving broad distribution of agents in the brain. Furthermore, the development of polymeric nanocarriers to encapsulate a variety of cargo, including small molecules, proteins, and nucleic acids, have allowed for formulations that protect and control the release of said cargo to extend its half-life. The combination of local delivery and nanocarriers presents an exciting opportunity to address the limitations of current chemotherapies for GBM toward the goal of improving safety and efficacy of treatment. However, much work remains to establish standard criteria for selection and implementation of these modalities before they can be widely implemented in the clinic. Ultimately, engineering principles and nanotechnology have opened the door to a new wave of research that may soon advance the stagnant state of GBM treatment development.

Fatal temozolomide induced aplastic anemia in a female with Glioblastoma multiforme : A case report and literature review

When seeing patients on Temozolomide with pancytopenia, aplastic anemia secondary to the drug should be considered early in the differentials to avoid permanent hematological suppression.

Survival in patients with glioblastoma at a first progression does not correlate with isocitrate dehydrogenase (IDH)1 gene mutation status

Backgrounds

Mutations in the isocitrate dehydrogenase (IDH)1 gene are favourable prognostic factors in newly diagnosed diffuse gliomas, whereas it remains controversial in the recurrent glioblastoma setting.

Methods

A total of 171 patients with newly diagnosed glioblastoma, either ‘primary’ glioblastoma or ‘secondary’ glioblastoma, treated at Kyorin University Hospital or Japanese Red Cross Medical Center from 2000 to 2015 were included. Patients with confirmed IDH1 status and O⁶-methylguanine-DNA methyltransferase promoter methylation status were retrospectively analysed for overall survival from the initial diagnosis (n = 147) and after the first progression (n = 122).

Results

IDH1 mutation but not IDH2 was noted in 19 of 147 patients with glioblastoma (12.9%). In patients with ‘primary’ glioblastoma (n = 136), median overall survival after the first progression was 13.5 and 10.5 months for mutant IDH1 and wild-type IDH1 glioblastoma, respectively (P = 0.747). Multivariate analysis revealed O⁶-methylguanine-DNA methyltransferase promoter methylation, and Karnofsky Performance status 60 or higher, were independent prognostic factors for better overall survival after the first progression. When ‘primary’ glioblastoma and ‘secondary’ glioblastoma were combined, median overall survival from the first progression was not significantly different between the mutant IDH1 group (10.1 months) and wild-type IDH1 group (10.5 months) (P = 0.559), whereas median overall survival from the initial diagnosis was significantly different (47.5 months vs.18.3 months, respectively; P = 0.035).

Conclusions

These results suggest that IDH1 mutation may not be a prognostic factor for survival at the first progression of patients with ‘primary’ glioblastoma and pretreated ‘secondary’ glioblastoma, and further warrant investigation in prospective studies.

Temozolomide-induced aplastic anaemia and incidental low-grade B-cell non-Hodgkin lymphoma in a geriatric patient with glioblastoma multiforme

Glioblastoma multiforme is an astrocyte-derived tumour representing the most aggressive primary brain malignancy. The median overall survival is 10-12 months, but it drops to 3-8.5 months for the cohort with more than 65 years old, which account to half of all patients. Initial management in this patient population aims to balance overall patient survival and quality of life with the inherent risks of treatment intervention, which include maximal safe tumour resection, radiation and temozolomide (TMZ) chemotherapy. This is accomplished through risk stratification as a function of patient age, functional status, comorbidities, tumour location and methylguanine methyltransferase promoter methylation status. We describe the care of a patient with prolonged febrile neutropaenia, with a rare but fatal complication from TMZ-induced idiosyncratic reaction, leading to aplastic anaemia and a provoking diagnosis of low-grade B-cell non-Hodgkin's lymphoma.

The role of microglia and P2X7 receptors in gliomas

Gliomas are the most prevalent tumours of the central nervous system and present with high morbidity and mortality. The most common and most aggressive form of glioma is glioblastoma multiforme, of which patients have a median survival time of only 12 to 15 months. Current treatment options are limited and have a small impact on clinical outcome and prognosis. There is accumulating evidence that microglia, the immunocompetent cells of the central nervous system, and the purinergic P2X7 receptor (P2X7R) may contribute to tumour progression and pathology. Importantly, P2X7R on both tumour cells and infiltrating microglia is overexpressed in animal and human glioma cultures. Factors released by glioma cells and P2X7R activation recruit microglia into the largely immunosuppressive tumour microenvironment where they have been demonstrated to contribute to either tumour proliferation or tumour suppression. It is likely that P2X7R mediates a range of microglia effector functions in the glioma setting, potentially increasing tumour growth and proliferation. This review evaluates current evidence on the roles of microglia and P2X7R in glioma pathogenesis. Understanding the nature, mechanisms and outcomes of microglia and P2X7R activation in gliomas is necessary for the development of more therapies with increased efficacy and specificity.

Temozolomide-related idiosyncratic and other uncommon toxicities: a systematic review

Temozolomide (TMZ)-related idiosyncratic and other uncommon toxicities have been reported. To better characterize these toxicities and to identify any associated risk factors, we performed a systematic review. We searched the PubMed database, limited to the English language, published between 1999 and December 2011. We selected only those articles in which TMZ was temporally related and was the sole or main contributing chemotherapeutic drug to idiosyncratic drug reactions (IDRs) and other uncommon toxicities. Hematological IDRs are biopsy-proven aplastic anemia or grade V toxicity or grade IV toxicity with slow and incomplete hematological recovery. Seventy-three cases were identified, including 21 hematological IDRs, 31 nonhematological IDRs and uncommon infections, and 21 second primary cancers. With a caveat of publication and reporting bias, the following observations could be made. The hematological IDRs predominantly occurred in female patients (exact binomial two-tailed, P=0.0041) and most patients were receiving TMZ concomitantly with radiotherapy for glioma. The median duration of exposure to TMZ was 30 days and the median cumulative TMZ exposure was 2250 mg/m (range, 500-6900 mg/m). The sex predilection was not evident in nonhematological IDRs and other uncommon toxicities. TMZ-induced pneumonitis and cholestatic hepatitis are emerging as a nonhematological hypersensitive reaction and IDR, respectively. For TMZ-related myelodysplasia or leukemia, the cumulative dose of TMZ ranged from 1400 to 30 000 mg/m. The cumulative dose of TMZ was lower and latency was shorter with a previous exposure to other leukemogenic drugs, suggesting that TMZ may have augmented the leukemogenic potential of other drugs. Early appearance of profound myelosuppression during the course of TMZ and concurrent radiotherapy could be a hematological IDR, which warrants prompt investigations to exclude aplastic anemia. Myelodysplasia or leukemia developed after a median TMZ exposure of 15 g/m.

Predictive significance of mean apparent diffusion coefficient value for responsiveness of temozolomide-refractory malignant glioma to bevacizumab: preliminary report

BACKGROUND

Recurrent glioblastoma after initial radiotherapy plus concomitant and adjuvant temozolomide is problematic. Here, patients with temozolomide-refractory high-grade gliomas were treated with bevacizumab (BV) and evaluated using apparent diffusion coefficient (ADC) for response.

METHODS

Nine post-temozolomide recurrent or progressive high-grade glioma patients (seven with glioblastoma and two with anaplastic astrocytoma) were treated with BV monotherapy. Average age was 57 years (range, 22-78), median Karnofsky Performance Scale (KPS) was 70 (30-80) and median BV line number was 2 (2-5). Two had additional stereotactic radiotherapy within 6 months prior to BV. Magnetic resonance (MR) imaging after BV therapy was performed within 2 weeks with calculation of mean ADC (mADC) values of enhancing tumor contours.

RESULTS

Post-BV treatment MR imaging showed decreased tumor volumes in eight of nine cases (88.9 %). Partial response was obtained in four cases (44.4 %), four cases had stable disease, and one had progressive disease. Of 15 evaluable enhancing lesions, 11 shrank and four did not. Pretreatment mADC values were above 1100 (10(-6) mm(2)/s) in all responding tumors, while all non-responding lesions scored below 1100 (p = 0.001). mADC decreased after the first BV treatment in all lesions except one. KPS improved in four cases (44.4 %). Median progression-free survival and overall survival for those having all lesions with high mADC (>1100) were significantly longer than those with a low mADC (<1100) lesion (p = 0.018 and 0.046, respectively).

CONCLUSIONS

Bevacizumab monotherapy is effective in patients with temozolomide-refractory recurrent gliomas and tumor mean ADC value can be a useful marker for prediction of BV response and survival.

Extended survival of glioblastoma patients after chemoprotective HSC gene therapy

Chemotherapy with alkylating agents for treating malignant disease results in myelosuppression that can significantly limit dose escalation and potential clinical efficacy. Gene therapy using mutant methylguanine methyltransferase (P140K) gene-modified hematopoietic stem and progenitor cells may circumvent this problem by abrogating the toxic effects of chemotherapy on hematopoietic cells. However, this approach has not been evaluated clinically. Here, we show efficient polyclonal engraftment of autologous P140K-modified hematopoietic stem and progenitor cells in three patients with glioblastoma. Increases in P140K-modified cells after transplant indicate selection of gene-modified hematopoietic repopulating cells. Longitudinal retroviral integration site (RIS) analysis identified more than 12,000 unique RISs in the three glioblastoma patients, with multiple clones present in the peripheral blood of each patient throughout multiple chemotherapy cycles. To assess safety, we monitored RIS distribution over the course of chemotherapy treatments. Two patients exhibited emergence of prominent clones harboring RISs associated with the intronic coding region of PRDM16 (PR domain-containing 16) or the 3' untranslated region of HMGA2 (high-mobility group A2) genes with no adverse clinical outcomes. All three patients surpassed the median survival for glioblastoma patients with poor prognosis, with one patient alive and progression-free more than 2 years after diagnosis. Thus, transplanted P140K-expressing hematopoietic stem and progenitor cells are chemoprotective, potentially maximizing the drug dose that can be administered.

A phase I study of LY317615 (enzastaurin) and temozolomide in patients with gliomas (EORTC trial 26054)

We report a phase 1 study to examine the safety and recommended dose of the oral protein kinase C-beta inhibitor (anti-angiogenic) enzastaurin in combination with single-agent temozolomide. The study was conducted in patients with recurrent glioblastoma or newly diagnosed disease that was not treatable with standard (chemo)radiotherapy. Patients were treated with standard dose temozolomide (200 mg/m(2) for 5 days every 4 weeks) together with daily oral enzastaurin. Three dose levels of enzastaurin were investigated: 250 mg daily (OD), 500 mg OD, and 250 mg twice daily (BID). Dose-limiting toxicity was determined in the first 2 cycles, but treatment continued until limiting toxicity or disease progression was identified. Twenty-eight patients were enrolled. No dose-limiting toxicity was noted at 250 mg OD or 500 mg OD. However, at 250 mg BID, 2 dose-limiting episodes of thrombocytopenia were noted. The recommended dose for enzastaurin in combination with standard 4-weekly temozolomide is therefore 500 mg OD. The pharmacokinetics of enzastaurin in combination with temozolomide was evaluated. Temozolomide did not appear to effect enzastaurin exposures at the 250 mg or 500 mg OD dose levels.

Toxicity after radiochemotherapy for glioblastoma using temozolomide--a retrospective evaluation

Purpose

Retrospective evaluation of toxicity and results after radiochemotherapy for glioblastoma.

Methods

46 patients with histopathologically proven glioblastoma received simultaneous radiochemotherapy (RCT). The mean age at the beginning of therapy was 59 years, the mean Karnofsky performance index 80%. 44 patients had been operated on before radiotherapy, two had not. A total dose of 60 Gy was applied in daily single fractions of 2.0 Gy within six weeks, 75 mg/m²/day Temozolomide were given orally during the whole radiotherapy period.

Results

A local progression could be diagnosed in 34/46 patients (70%). The median survival time amounted to 13.6 months resulting in one-year and two-year survival probabilities of 48% and 8%, respectively.

Radiotherapy could be applied completely in 89% of the patients. Chemotherapy could be completed according to schedule only in 56.5%, the main reason being blood toxicity (50% of the interruptions). Most of those patients suffered from leucopenia and/or thrombopenia grade III and IV CTC (Common toxicity criteria). Further reasons were an unfavourable general health status or a rise of liver enzymes.

The mean duration of thrombopenia and leucopenia amounted to 64 and 20 days. In two patients, blood cell counts remained abnormal until death. In two patients we noticed a rise of liver enzymes. In one of these in the healing phase of hepatitis a rise of ASAT and ALAT CTC grade IV was diagnosed. These values normalized after termination of temozolomide medication. One patient died of pneumonia during therapy.

Conclusion

Our survival data were well within the range taken from the literature. However, we noticed a considerable frequency and intensity of side effects to bone marrow and liver. These lead to the recommendations that regular examinations of blood cell count and liver enzymes should be performed during therapy and temozolomide should not be applied or application should be terminated according to the criteria given by the manufacturer.

Immature and absolute platelet count changes and thrombocytopenia in malignant glioma

BACKGROUND

Temozolomide (TMZ) is commonly used for the therapy of malignant glioma and induces thrombocytopenia in a fraction of patients. Currently, no biomarkers predicting TMZ-induced thrombocytopenia are available. In this study, we investigated whether changes in platelet count (PLT) or the immature platelet fraction (IPF) may serve as predictor of TMZ-induced thrombocytopenia in malignant glioma patients.

METHODS

 We prospectively included 52 malignant glioma patients receiving TMZ-containing therapy regimens in this study. Platelet counts and IPF were determined at each clinical follow-up visit (weekly during concomitant radiochemotherapy or at least monthly during TMZ monotherapy) using the Sysmex XE-2100 system. We explored the diagnostic utility of PLT change/day and IPF change/day from the last to the current follow-up visit for the prediction of clinically relevant thrombocytopenia (PLT < 100·000 μl(-1) ) at the next follow-up visit.

RESULTS

Relevant thrombocytopenia was observed in 10 of 234 occasions. The areas under the receiver operating characteristic curves for PLT absolute change/day, PLT relative change/day and IPF relative change/day were 0·675, 0·703 and 0·663, respectively. The Youden indices (maximum sum of sensitivity and specificity minus one) were 0·31, 0·39, and 0·29, respectively. The corresponding positive predictive values were 16%, 57%, and 6·7%, and the negative predictive values were 97%, 97%, and 98%, respectively.

CONCLUSIONS

The rather moderate diagnostic potential of our data indicate that the time course of PLT counts and IPF measured at routine clinical follow-up are not useful for the prediction of thrombocytopenia in glioma patients treated with TMZ.

Another cause of pancytopenia in a patient receiving temozolomide

OBJECTIVE

To report pancytopenia caused by temozolomide, a second-generation alkylating agent.

CLINICAL PRESENTATION AND INTERVENTION

A 22-year-old patient presenting with seizures and confusion was seen in the emergency room. Cranial magnetic resonance imaging revealed a mass. After surgery, the patient was diagnosed with glioblastoma multiforme and was given temozolomide at 150 mg/m(2) on days 1 through 5 every 4 weeks. During the last cycle of temozolomide, grade 3 thrombocytopenia persisted. Possible causes of pancytopenia including vitamin B(12) deficiency were investigated.

CONCLUSION

This case report shows that vitamin B(12) deficiency can be a potential cause of pancytopenia and it should be kept in mind for patients receiving chemotherapy.

Metronomic treatment of malignant glioma xenografts with irinotecan (CPT-11) inhibits angiogenesis and tumor growth

Irinotecan (CPT-11) has shown emerging promise in the treatment of malignant gliomas. It is believed the mechanism of action of irinotecan is to sensitize glioma cells to the cytotoxic action of radiation therapy and alkylating agents. However, clinical trials using weekly or three-weekly doses of CPT-11 have demonstrated imaging responses in only 10-15% of patients. In this study, we evaluated another mechanism of action, angiosuppression by CPT-11 of ACNU-resistant gliomas, using a metronomic administration schedule. Two different types of treatment, (1) conventional and (2) metronomic, were applied to the subcutaneous U87 model. We found that metronomic administration of CPT-11 significantly inhibited malignant glioma growth by inhibiting angiogenesis; this treatment procedure reduced the number of tumor vessels and the area of hypoxic lesions and reduced expression of VEGF and HIF-1alpha, the most important angiogenic factors in gliomas. Metronomic treatment was superior to conventional treatment with regard to the severe systemic side effect of body weight loss. The growth inhibitory effect was very similar for both low and high doses of CPT-11. These angiosuppressive effects of CPT-11 show promise for another use of CPT-11 in metronomic and scheduled angiosuppressive chemotherapy with low dose and long-term administration for malignant gliomas without systemic side effects.