Treatment Of Primary Glioblastoma Multiforme Research Articles

Abstract 1490: Dual chlorotoxin and methylguanine methyltransferase γδ-T cells for drug resistant immunotherapy of glioblastoma multiforme

Abstract While recent advances in immunotherapies have shown promise in extracranial tumors, Glioblastoma Multiforme (GBM) has remained impervious to these advances with a consistent median survival of 15 months. We have developed a novel approach to the treatment of primary GBM by combining simultaneous intracranial administration of gene-modified γδ T cells and standard temozolomide (TMZ) maintenance chemotherapy. These γδ T cells are transduced with O-6-Methylguanine-DNA Methyltransferase (MGMT), conveying resistance to alkylating chemotherapies, thereby allowing effector function at therapeutic concentrations of TMZ when tumor NKG2DL expression is significantly elevated. We modified γδ T cells with a lentivector construct expressing a chimeric antigen receptor (CAR) with a chlorotoxin binding domain (CLTX-CAR) to improve GBM targeting. CLTX is a small natural peptide derived from scorpion venom that specifically targets altered expression of matrix metalloproteinase 2 (MMP2) and chloride channel CLCN3 on GBM. MGMTp140k was co-expressed within the same CLTX-CAR vector to confer TMZ resistance to the CAR-T cells. The CLTX-CAR vectors contain a CD8α signal peptide, a mono or dual CLTX binding domain, a Myc-Tag peptide, a CD8α hinge domain, a CD28 transmembrane domain, and a costimulatory domain followed by a CD3ζ activation domain. We used P2A peptide to co-express MGMTp140k with the CAR. Initially, we demonstrated efficient transduction of the CLTX-CAR with a dual-CLTX construct as the binding domain (dCLTX-CAR) in Jurkat T cells. Cell surface localization of the dCLTX-CAR was verified by flow cytometry. When compared with the mono-CLTX-CARs (mCLTX-CARs) transduced Jurkat cells, the dCLTX-CARs demonstrated increased CD69 activation (MFI= 4873 vs 1078) and greater cytotoxicity against tumor cells in vitro. The modified T cells also demonstrated enhanced cytotoxicity against tumor cells under TMZ exposure in vitro. Since γδ T cells recognize and kill tumors through NKG2DL stress antigen recognition, we hypothesized that a CLTX-CAR without an activation signal may be sufficient to enhance recognition and cytotoxicity of γδ T cells to tumor cells and mitigate CAR-T activation-induced cell death. We then developed dCLTX-CAR constructs without the CD3ζ domain (dCLTX- Δz-CARs). As expected, the dCLTX-Δz-CAR lentivirus transduced Jurkat cells demonstrated enhanced cell-cell binding compared to the full dCLTX-CAR but no CD69 expression when co-cultured with GBM cells. Overall, we were able to generate dCLTX-CAR T cells with resistance to TMZ and showed improved activation and cytotoxicity against GBM cells under TMZ exposure. Our approach of combining the dCLTX-CAR and TMZ resistance will be further validated in animal model experiments and could be a potential candidate for clinical development for GBM. Citation Format: Lei Ding, Lawrence S. Lamb. Dual chlorotoxin and methylguanine methyltransferase γδ-T cells for drug resistant immunotherapy of glioblastoma multiforme [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1490.

SURG-15. SURVIVAL OUTCOMES FOLLOWING RE-RESECTION FOR RECURRENT GLIOBLASTOMA MULTIFORME

Abstract BACKGROUND While the treatment of primary Glioblastoma Multiforme (GBM) is well defined, the role of surgical resection in recurrent GBM is not firmly established.1 Treatment options for recurrent GBM include second-line chemotherapy, re-irradiation and surgical re-resection.2 This review examines current practice in a national neuro-oncology centre. AIMS: To investigate survival outcomes in patients undergoing surgical re-resection for recurrent GBM in our institution and to compare our findings to the relevant published literature. METHODS A retrospective review of our institution’s neuro-oncology database was performed. We evaluated all patients who underwent re-resection for recurrent GBM following standard adjuvant treatment between 2015–2018. Patients who did not have an initial diagnosis of Grade 4 GBM and patients who were re-operated on within one month were excluded. We analysed overall survival using Kaplan Meier curves. Patients not known to have died were censored to the last known alive date. We also examined factors which may affect patient outcome, including age, sex, extent of resection, tumour characteristics and tumour location. RESULTS 34 patients were eligible for inclusion into this study, of these 21 (61%) were male. Median age was 52. A radiologically confirmed initial resection of > 80% was achieved in 52% of patients. Median time from initial surgery to re-resection was 13.5 months. Median survival from initial surgery was 28.6 months and median survival after re-resection was 9.5 months. CONCLUSION Re-operation appears to have a role in the management of recurrent GBM in carefully selected cases. Overall survival in this patient cohort remains poor and further studies into the benefit of re-resection in comparison to second-line chemotherapy and re-irradiation would be of value.

Synthesis of [3-N-(11) C-methyl]temozolomide via in situ activation of 3-N-hydroxymethyl temozolomide and alkylation with [(11) C]methyl iodide.

Temozolomide is a chemotherapeutic drug that is mainly used in the treatment of primary glioblastoma multiforme and recurrent high-grade glioma. Here, we report an efficient good manufacturing practice compliant method for the synthesis of [3-N-(11) C-methyl]temozolomide from 3-N-hydroxymethyl temozolomide that cleaves off formaldehyde in situ and becomes activated towards alkylation with [(11) C]methyl iodide. The labelling method was developed for an on-going patient study in which the predictive value of [3-N-(11) C-methyl]temozolomide and positron emission tomography on the outcome of temozolomide treatment is being investigated. The precursor was reacted with [(11) C]methyl iodide in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene in acetonitrile, heated at stepwise increasing temperature. Purification by semipreparative HPLC with pharmaceutical grade eluent and filtration gave approximately 10 mL sterile product solution ready for injection containing 1.55 ± 0.38 GBq (n = 5), the specific activity was 88 ± 25 GBq/µmol and the radiochemical purity was 98.5 ± 1.9%. (13) C-NMR spectroscopy confirmed the labelled position after colabelling with (11) C and (13) C.

Secondary gliosarcoma after the treatment of primary glioblastoma multiforme

Gliosarcoma is a rare variant of glioblastoma multiforme containing distinct gliomatous and sarcomatous components. Gliosarcoma comprise 1.8-8% of glioblastoma multiforme and are clinically similar to them, affecting adults in the fourth and sixth decades of life, with a higher proportion found in males. The survival for patients with Gliosarcoma is equally poor as for those with glioblastoma multiforme, and there is a greater propensity for extracranial metastasis in Gliosarcoma. Clinical treatment-related experience reported in the literature is limited, and Gliosarcoma are currently treated in a similar fashion to glioblastoma multiforme, with modalities including tumor resection, postoperative radiation therapy, and chemotherapy. Gliosarcoma can arise secondarily, after conventional adjuvant treatment of high-grade glioma. The current literature on the occurrence of secondary gliosarcoma after glioblastoma multiforme is limited, with only 54 reported cases.The authors present a 48-year-old Caucasian male who had previously received postoperative combined radiation and temozolomide chemotherapy for glioblastoma multiforme. After a free disease period of 9 months the disease recurs as Gliosarcoma. The patient underwent a Total surgical excision and received chemotherapy with a basis of bevacizumab and irinotecan. The patient died from tumor progression 5 months after gliosarcoma diagnosis.The poor survival of patients with secondary gliosarcoma who had previously received combined radiation and temozolomide chemotherapy for glioblastoma multiforme may reflect a unique molecular profile of glioblastoma multiforme that eventually recurs as secondary gliosarcoma. We have to keep in mind the possibility of gliosarcomatous change in the recurrence of malignant glioma. Awareness of this pathological entity will allow more rapid diagnosis and treatment.

Secondary gliosarcoma: a review of clinical features and pathological diagnosis

Although secondary gliosarcoma after treatment of primary glioblastoma multiforme has been described, little is known of these rare tumors. In this article the authors review the literature on secondary gliosarcoma, with attention to clinical course and pathological features. A PubMed search of the key word intracranial "gliosarcoma" with and without "radiation" or "radiotherapy" in humans was performed. The 204 citations yielded were screened for relevancy to gliosarcomas that occur after treatment of previous intracranial neoplasms. A search of the literature yielded 24 relevant articles, combined for a total of only 12 cases of secondary gliosarcoma and 12 cases of radiation-induced gliosarcoma. Of the 12 cases of secondary gliosarcoma, all were previously treated with surgery and radiotherapy (mean dose 50.7 Gy), with a mean survival of 13 months since time of gliosarcoma diagnosis (range 6.9-19.4 months). In the cases of radiation-induced gliosarcoma, the mean dose of previous radiotherapy was 51.3 Gy (median 54 Gy, range 24-60 Gy), and the mean survival since gliosarcoma diagnosis was 6.7 months (median 6 months, range 2-10 months). Secondary gliosarcoma and radiation-induced gliosarcoma are exceedingly rare. The literature on secondary gliosarcoma illustrates a more favorable survival than for primary gliosarcoma but remains limited regarding clinical and radiographic presentation, response to treatment, and pathogenesis. The results of the present review also support the notion that secondary gliosarcomas and radiation-induced gliosarcomas are distinct entities, with longer survival and shorter latency of gliosarcoma induction seen in the former. Efforts to elucidate the role of radiotherapy in the induction of gliosarcomas may yield new insights into therapeutic risks of cranial radiation and CNS tumor pathogenesis.

Postoperative Treatment of Primary Glioblastoma Multiforme With Radiation and Concomitant Temozolomide in Elderly Patients

To evaluate efficacy and toxicity in elderly patients with glioblastoma multiforme (GBM) treated with postoperative radiochemotherapy with temozolomide (TMZ). Forty-three patients aged 65 years or older were treated with postoperative with radiochemotherapy using TMZ for primary GBM. Median age at primary diagnosis was 67 years; 14 patients were female, 29 were male. A complete surgical resection was performed in 12 patients, subtotal resection in 17 patients, and biopsy only in 14 patients. Radiotherapy was applied with a median dose of 60 Gy, in a median fractionation of 5x2 Gy/wk. Thirty-five patients received concomitant TMZ at 50 mg/m2, and in 8 patients 75 mg/m2 of TMZ was applied. Adjuvant cycles of TMZ were prescribed in 5 patients only. Median overall survival was 11 months in all patients; the actuarial overall survival rate was 48% at 1 year and 8% at 2 years. Median overall survival was 18 months after complete resection, 16 months after subtotal resection, and 6 months after biopsy only. Median progression-free survival was 4 months; the actuarial progression-free survival rate was 41% at 6 months and 18% at 12 months. Radiochemotherapy was well tolerated in most patients and could be completed without interruption in 38 of 43 patients. Four patients developed hematologic side effects greater than Common Terminology Criteria Grade 2, which led to early discontinuation of TMZ in 1 patient. Radiochemotherapy is safe and effective in a subgroup of elderly patients with GBM and should be considered in patients without major comorbidities.

Stereotactically Guided Fractionated Re-irradiation in Recurrent Glioblastoma Multiforme

To assess the feasibility, efficacy and toxicity of fractionated stereotactic radiotherapy in the treatment of recurrent glioblastoma multiforme. From January 1995 to July 2003, 53 patients with histologically proven glioblastoma multiforme were treated at recurrence with fractionated stereotactic radiation therapy. A median dose of 36 Gy using a median fractionation of 5 x 2 Gy/week was applied. Median overall survival was 21 months, and median overall survival from the time point of re-irradiation was 8 months. The median time interval between primary and secondary radiation therapy was 10 months. In this patient population, no variables predicting longer overall survival could be determined. However, neurosurgical resection at relapse was associated with increased survival after re-irradiation (p=0.04), but left progression-free survival unaltered. Treatment was well-tolerated and no severe toxicities developed. Stereotactically guided fractionated re-irradiation is a safe and effective treatment modality in selected cases of recurring glioblastoma multiforme. Since this is not a randomized study, further evaluation in larger patient collectives is warranted. Also, based on recent results of radiochemotherapy in the treatment of primary glioblastoma multiforme, concomitant chemotherapy at relapse might be considered in the future.

Temozolomide Combined with Irradiation as Postoperative Treatment of Primary Glioblastoma Multiforme

The role of radiochemotherapy in the treatment of primary glioblastoma multiforme is still discussed controversially. To evaluate the feasibility and toxicity of irradiation and concomitant administration of 50 mg/m2 temozolomide in patients with primary malignant glioma, this phase I/II study was conducted. 53 Patients with histologically confirmed WHO grade IV malignant glioma were enrolled into the study. All patients were treated with radiation therapy up to a total dose of 60 Gy using conventional fractionation of 5 × 2.0 Gy/week. Temozolomide was administered orally each therapy day at a dose of 50 mg/m2. Prior to radiochemotherapy, complete resection (n = 14), subtotal resection (n = 22) or a biopsy (n = 17) of the tumor was performed. The median time interval between surgery and radiochemotherapy was 21 days. Treatment-related toxicity was very mild. Acute toxicity > grade 2 was observed in one patient who developed grade 4 hemotoxicity. Minor side effects of chemotherapy included nausea and vomiting. No severe late effects were observed. Median progression-free and overall survival were 8 and 19 months, respectively. The overall survival rate was 72% at 1 and 26% at 2 years. Age and extent of surgery significantly influenced survival. The combination of temozolomide plus radiation therapy is feasible and safe in terms of toxicity. Overall survival times were relatively long compared to survival times reported for radiotherapy alone. The application of 50 mg/m2 of temozolomide can be performed throughout the whole time course without interruption due to side effects and might largely contribute to the prolonged overall survival. Further evaluation is warranted as to which dose of temozolomide is optimal with regard to tumor response and toxicity.

87 oral Intensity modulated radiation therapy (IMRT) in the treatment of primary glioblastoma multiforme: retrospective survival analysis

87 oral Intensity modulated radiation therapy (IMRT) in the treatment of primary glioblastoma multiforme: retrospective survival analysis

Phase I/II-study of temozolomide combined with radiation as postoperative treatment in primary glioblastoma multiforme

The role of chemotherapy in combination with radiation therapy is still discussed controversially in the treatment of primary glioblastoma multiforme. To evaluate the feasibility and toxicity of radiation and concomitant administration of temozolomide in patients with primary malignant glioma, this phase I/II study was conducted.

Phase I/II-study of temozolomide combined with radiation as postoperative treatment in primary glioblastoma multiforme

The role of chemotherapy in combination with radiation therapy is still discussed controversially in the treatment of primary glioblastoma multiforme. To evaluate the feasibility and toxicity of radiation and concomitant administration of temozolomide in patients with primary malignant glioma, this phase I/II study was conducted.

Temozolomide combined with radiation as first-line treatment in primary glioblastoma multiforme: Phase I/II-study

1531 Background: The role of chemotherapy in combination with radiation therapy is still discussed controversially in the treatment of primary glioblastoma multiforme. To evaluate the feasibility and toxicity of radiation and concomitant administration of temozolomide in patients with primary malignant glioma, this phase I/II study was conducted. Methods: 53 Patients with histologically confirmed WHO °IV malignant glioma were enrolled in the study. All patients were treated with radiation therapy with a total dose of 60Gy using conventional fractionation of 5x2.0Gy/week. Temozolomide was administered orally each therapy day at a dose of 50mg/m2. Results: Prior to radio-chemotherapy, complete resection of the tumor was performed in 14 patients, 22 patients received a subtotal resection, and in 17 patients only a biopsy could be performed. The median time interval between surgery and initiation of radio-chemotherapy was 21 days. Treatment related toxicity was very mild. Acute toxicity > °II was observed in one patient who developed °IV hemotoxicity. Minor side effects of chemotherapy included nausea and vomiting which could be managed with odansetron medication. No severe late effects were observed. The median progression-free survival and the median overall survival were 8 months and 19 months, respectively. Actuarial overall survival was 72% at 1 year and 29% at 2 years. Age < 40 vs. > 40 and extent of surgery significantly influenced survival. Conclusion: The combination of temozolomide plus radiation therapy is feasible and safe by means of toxicity. Overall survival times were relatively high compared to the survival times reported for radiotherapy alone. By applying a dosage of 50mg/m2of temozolomide, application can be performed throughout the whole time course without interruption due to side effects and might contribute in a large manner to the prolonged overall survival. A clinical phase III trial is warranted to prove the superiority of combined radiotherapy with temozolomide compared to radiotherapy alone. No significant financial relationships to disclose.

Temozolomide combined with radiation as first-line treatment in primary glioblastoma multiforme: Phase I/II-study

1531 Background: The role of chemotherapy in combination with radiation therapy is still discussed controversially in the treatment of primary glioblastoma multiforme. To evaluate the feasibility and toxicity of radiation and concomitant administration of temozolomide in patients with primary malignant glioma, this phase I/II study was conducted. Methods: 53 Patients with histologically confirmed WHO °IV malignant glioma were enrolled in the study. All patients were treated with radiation therapy with a total dose of 60Gy using conventional fractionation of 5x2.0Gy/week. Temozolomide was administered orally each therapy day at a dose of 50mg/m2. Results: Prior to radio-chemotherapy, complete resection of the tumor was performed in 14 patients, 22 patients received a subtotal resection, and in 17 patients only a biopsy could be performed. The median time interval between surgery and initiation of radio-chemotherapy was 21 days. Treatment related toxicity was very mild. Acute toxicity > °II was observed in one patient who developed °IV hemotoxicity. Minor side effects of chemotherapy included nausea and vomiting which could be managed with odansetron medication. No severe late effects were observed. The median progression-free survival and the median overall survival were 8 months and 19 months, respectively. Actuarial overall survival was 72% at 1 year and 29% at 2 years. Age < 40 vs. > 40 and extent of surgery significantly influenced survival. Conclusion: The combination of temozolomide plus radiation therapy is feasible and safe by means of toxicity. Overall survival times were relatively high compared to the survival times reported for radiotherapy alone. By applying a dosage of 50mg/m2of temozolomide, application can be performed throughout the whole time course without interruption due to side effects and might contribute in a large manner to the prolonged overall survival. A clinical phase III trial is warranted to prove the superiority of combined radiotherapy with temozolomide compared to radiotherapy alone. No significant financial relationships to disclose.

Hypofractionated intensity-modulated radiotherapy for primary glioblastoma multiforme

PurposeA pilot study was designed to evaluate the safety and efficacy of a novel regimen of hypofractionated intensity-modulated radiotherapy (RT) in the adjuvant treatment of primary glioblastoma multiforme (GBM). The rationale of the study was to combine the potential radiobiologic advantage of hypofractionation to GBM with a highly conformal radiotherapeutic technique. The study was designed to measure the acute and chronic morbidity of patients treated with this regimen, response of GBM to the treatment, overall survival, and time to disease progression after therapy completion. Methods and materialsTwenty eligible patients were accrued between February 1999 and May 2000 for the study. All patients had Karnofsky performance scores of ≥70. All patients were treated with intensity-modulated RT using the NOMOS Peacock system. A dose of 50 Gy was delivered in 5-Gy daily fractions within 2 weeks to enhancing primary disease, residual tumor, or surgical cavity. Simultaneously, 30 Gy was prescribed in 3-Gy daily fractions to surrounding edema. The time to progression was measured with serial neurologic examinations and MRI or CT scans after RT completion. Acute and late toxicity was graded using Radiation Therapy Oncology Group neurotoxicity scores. ResultsOf the 20 patients, 18 were evaluated for outcome. The median time to disease progression was 6 months after RT completion. The median overall survival was 7 months after treatment completion. All recurrences were within 2 cm of the operative bed. Neurotoxicity during therapy was minimal, with all patients experiencing Grade 0 or 1 toxicity. Late toxicity included 10 patients with Grade 0, 2 patients with Grade 2, and 3 patients with Grade 4 toxicity, manifesting as brain necrosis requiring surgical reexcision. The survival of the 3 patients with brain necrosis was 23, 20, and 9 months. Mortality in all cases was the result of tumor recurrence, with no mortality resulting from brain necrosis. ConclusionThis regimen of hypofractionated intensity-modulated RT did not improve the time to disease progression or overall survival compared with historical experience using conventional fractionation. However, the treatment duration was reduced from 6 weeks to 2 weeks, which may be of palliative benefit in certain subsets of patients. This treatment regimen demonstrated a greater incidence of brain necrosis requiring surgical intervention; however, the 3 patients experiencing this toxicity had longer survival times. Future investigation may be useful to determine which fraction size may be optimal for GBM when highly conformal RT is used in the adjuvant setting.