Hemoglobin, albumin, lymphocytes and platelets (HALP) score is a useful predictor of survival in patients with recurrent glioblastoma multiforme treated with bevacizumab plus irinotecan

Backgrounds: We aimed to investigate whether the HALP score is a predictive marker in patients with recurrent GBM who were given bevacizumab plus irinotecan.Methods: We compared the survival of patients followed up in our clinic with the diagnosis of recurrent GBM and treated with bevacizumab plus irinotecan, according to HALP score.Results: Median PFS and OS were 4.5 (0.9-14.9) and 8 (0.9-21.3) months, respectively. The median PFS of the low HALP score group was 1.85 (1.3-3.37) months, and of the high HALP score group was 4.96 (0.9-14.9) months (p=0.03). The OS of the high HALP score group (9.63 [7.28-11.9]) was statistically higher compared with low HALP score group (2.26 [0.88-3.65]) (p<0.001). In univariate analysis HALP score was a significant prognostic factor; patients with low HALP score had a poorer prognosis than high HALP score (HR: 0.063, p<0.001). The multivariate analysis showed that HALP score (p=0.003), and residual tumor (p=0.029) were significant prognostic factors. In multivariate Cox regression analysis, low HALP score was a significant poor prognostic factor for OS compared with high HALP score (HR: 0.063, p<0.001). Conclusion: We showed that the HALP score at the start of treatment is an independent prognostic factor for PFS and OS in patients with recurrent GBM treated with bevacizumab plus irinotecan. The HALP score, which can be easily calculated by routine tests before chemotherapy, can be used as a predictive marker for bevacizumab treatment decision.

Bevacizumab-induced isolated oculomotor nerve palsy in glioblastoma multiforme

Introduction: Bevacizumab, a monoclonal antibody against the vascular endothelial growth factor receptor, is the standard treatment of recurrent glioblastoma multiforme. In addition to common systemic side effects of bevacizumab, there are rare cases of cranial nerve palsy. Case report: We report a case of transient oculomotor nerve palsy after systemic administration of bevacizumab. Twenty-four hours after the systemic infusion of bevacizumab, transient oculomotor nerve palsy developed in a 49-year-old male patient. In the cranial MRI, there was no malignancy-related progression. Management and outcome: Bevacizumab treatment was discontinued. Methylprednisolone was started considering that bevacizumab increased the inflammatory response. Oculomotor nerve palsy resolved in 14 days. Discussion: There are many side effects of bevacizumab whose mechanisms of action have not been fully explained. Cranial nerve involvement is rarely reported. Our case is the first reported case of bevacizumab-induced oculomotor nerve palsy.

RTID-03. DESIGN AND INITIATION OF PIVOTAL STUDIES FOR BERUBICIN, A NOVEL, POTENT TOPOISOMERASE II POISON FOR THE TREATMENT OF RECURRENT GLIOBLASTOMA MULTIFORME (GBM)

Berubicin (WP744) is a doxorubicin analog that crosses the blood-brain barrier (BBB), shows significant CNS uptake, and induces more DNA damage but lower lethality than doxorubicin at equivalent doses. Berubicin also prolongs the survival time of intracranial orthotopic glioma models in mice compared to temozolomide, currently the standard of care in GBM. A Phase 1 study at MD Anderson in patients with recurrent glioma treated with escalating doses of Berubicin administered qdx3 repeated q21 days showed that it was well tolerated, with myelosuppression (neutropenia and thrombocytopenia) as the dose-limiting toxicity. Of 25 patients evaluable for efficacy, there was 1 complete response (13+ years), 1 partial response, and 10 patients with stable disease for a clinical benefit rate of 48%. To assure a rapid and economically practicable development program, two companies have collaborated to conduct trials in the US and EU, leading to a potentially more rapid approval of Berubicin for treating GBM in patients with limited options. CNS Pharmaceuticals, Inc. has initiated a randomized, controlled clinical trial of Berubicin vs. lomustine in adults with recurrent GBM. WPD Pharmaceuticals has sub-licensed Berubicin to study recurrent GBM in adults in an open-label trial. This is a unique collaboration in which the same overall design, eligibility criteria, procedures, and database for patients receiving Berubicin are used by both companies, ensuring that there will be a more robust and substantial data set for evaluation of activity and safety. The primary endpoint of the CNS study, to be conducted in the US and Europe, is overall survival (OS). The WPD study conducted in the EU has a primary endpoint of overall response rate (ORR). The data from these two trials are expected to provide sufficient information to support a potential registration program in both the US and EU for the treatment of patients with glioblastoma.

CTNI-25. CASE STUDY OF AN EXCEPTIONAL RESPONDER: ENZASTAURIN LONG TERM EFFICACY IN A PATIENT WITH PRIMARY AND RECURRENT GLIOBLASTOMA MULTIFORME (GBM)

Enzastaurin (ENZA, DB102) is an oral serine/threonine kinase inhibitor targeting the protein kinase C (PKC) and phosphoinositide 3-kinase (PI3K)/AKT pathways to inhibit tumor cell proliferation, induce tumor cell apoptosis, and suppress tumor-induced angiogenesis. We report the long-term clinical response of a GBM patient treated with ENZA who has survived for 15 years from initial diagnosis, despite tumor recurrence 5 years ago. In 2006, the 44-year-old man was diagnosed with GBM and underwent surgical resection of the tumor. He subsequently enrolled in a Phase I/II trial evaluating ENZA in newly diagnosed GBM and gliosarcoma (NCT00402116), in September 2006. He was treated with radiation and concurrent temozolomide (TMZ) + ENZA, followed by adjuvant TMZ + ENZA, which he tolerated well. He stopped treatment electively in November 2010, after 51 adjuvant cycles, in the setting of stable imaging without evidence of tumor activity. The patient did well until January 2016, when a serial MRI scan showed tumor progression; he underwent a second surgical resection (pathology: recurrent GBM, IDH1 R132H neg, ATRX retained, EGFR amplified, MGMT methylated) followed by re-irradiation with concurrent TMZ. Given the patient’s prior prolonged disease control, he started a compassionate treatment of ENZA in combination with adjuvant TMZ in April 2016. TMZ was stopped in June 2018 after 28 cycles; he continues single agent ENZA to date, with no evidence of tumor progression as of May 2021. Consistent with DGM1 (Denovo Genomic Marker 1) being an ENZA efficacy predicting biomarker, the patient is DGM1 positive. This case provides clinical evidence that the addition of ENZA to standard of care may provide substantial long-term benefit in DGM1 positive patients with GBM. A Phase 3 study of ENZA in DGM1 positive newly diagnosed GBM patients is currently ongoing (ENGAGE study, NCT03776071).

CTNI-49. PHASE 1 STUDY OF ST101, A FIRST-IN-CLASS PEPTIDE ANTAGONIST OF CCAAT/ENHANCER-BINDING PROTEIN ß, IN PATIENTS WITH ADVANCED SOLID TUMORS, WITH A PHASE 2 EXPANSION IN RECURRENT GLIOBLASTOMA MULTIFORME

BACKGROUND C/EBPβ is a transcription factor that is active during embryofetal development but held in an inactive state in most mature cells (Zahnow 2009). C/EBPβ is upregulated or overactivated in multiple cancers, where it inversely correlates with disease prognosis and survival due to activation of a gene signature that promotes tumor cell proliferation and survival. ST101 is a cell-penetrating peptide antagonist of C/EBPβ. ST101 exposure leads to selective tumor cell death in multiple human cancer cell lines, including GBM, without impacting normal cell viability. In vivo, ST101 displays rapid uptake into multiple organs, the ability to cross the blood-brain barrier, and a long plasma half-life due to its resistance to degradations. It has potent anti-tumor activity in multiple GBM models, as a single agent or in combination, which supported moving into clinical development. TRIAL DESIGN This phase 1-2 study is enrolling patients ≥ 18 years of age with advanced, unresectable metastatic solid tumors refractory to or intolerant of other therapeutic options. We began recruitment in August 2020. The primary objective of phase 1 is to evaluate safety and tolerability of ST101. Secondary objectives include the recommendation of a dose and regimen of ST101 for further evaluation, pharmacokinetics, several pharmacodynamic measures, and preliminary efficacy. Patients receive intravenous ST101 once weekly in a standard 3 + 3 design. Enrollment is ongoing, and by 21 May 2021, 15 patients have been recruited in four dose-escalation cohorts up to 4 mg/kg; a 5th cohort (6 mg/kg) is ongoing. The recommended phase 2 dose will be used in a 15-30 patient GBM expansion cohort, with a Simon 2-stage design, which requires one response or two patients with PFS6 in the first cohort to continue the study. Up to 120 patients are planned in a total of four expansion cohorts, which should be enrolling by Q3 2021.

P.161 Management of recurrent glioblastoma multiforme: An inter-observer variability study

Background: A significant proportion of glioblastoma multiforme (GBM) patients are considered for repeat resection, but evidence regarding best management remains elusive. Methods: An electronic portfolio of MR images of 37 cases of pathologically confirmed recurrent GBM with an accompanying clinical vignette was constructed. Surgical responders from various countries, training backgrounds, and years’ experience were asked for each case to select: their chosen management (repeat surgery, chemotherapy, radiation, or conservative), confidence in recommended management, and whether they would include the patient in a randomized trial that gave a 50% chance of re-operation. Responses were evaluated with kappa statistics and values interpreted according to Landis and Koch (0–0.2, slight; 0.21–0.4, fair; 0.41–0.6, moderate; 0.61–0.8, substantial; 0.81-1.0 perfect agreement). Results: 26 surgeons responded to the survey. Agreement regarding best management of recurrent GBM was slight, even when management options were dichotomized (repeat surgery vs. all others) (k=0.198 (95%CI 0.133-0.276). Country of practice, years’ experience, and training background did not improve agreement. Responders were willing to include more than 70% of patients in a randomized trial. Conclusions: Only slight agreement exists regarding the question of re-operation for patients with recurrent GBM. This supports the need for a randomized controlled trial.

CLRM-09. INCORPORATING EXTERNAL CONTROL ARM IN MDNA55 RECURRENT GLIOBLASTOMA REGISTRATION TRIAL

BACKGROUND Drug development in recurrent glioblastoma multiforme (rGBM) is challenging. For randomized controlled trials (RCTs) short survival horizons and limited life-prolonging treatment options may delay accrual and introduce bias through differential dropout of control patients. Comparing results of a single-arm Phase 2b trial of intratumoral delivery of MDNA55 (an interleukin-4 receptor targeted fusion protein) to an external control arm, we sought early efficacy insights and consideration by the FDA of incorporating an ECA in a Phase 3 registrational trial. METHODS Using propensity score weighting, we compared rGBM patients from the Phase 2b trial (NCT02858895) (2017-2019) to patients from rGBM registries who had received standard of care therapies (2011-2019) and met eligibility requirements. Propensity scores were estimated using a logistic regression model with 11 covariates. We compared the propensity score weighted groups according to demographic and disease attributes before and after weighting and compared overall survival between the two groups. RESULTS Through propensity score weighting, 43 (98%, 43/44) MDNA55 patients and 40.80 weighted ECA patients (from 62 unweighted registry patients) were identified for comparison. MDNA55 and ECA patients were balanced on all baseline characteristics (i.e., standardized mean difference ≤ 0.15). Compared to ECA patients, MDNA55 patients had a 37% lower hazard of death (hazard ratio 0.63, 95% confidence interval: 0.39,1.02). CONCLUSION In advance of a Phase 3 trial, comparison of Phase 2b trial results to an ECA suggests that MDNA55 may be efficacious in rGBM. In view of the known challenges associated with drug development for rGBM, these results provided a proof-of-concept for the design of a novel hybrid Phase 3 trial. This planned Phase 3 trial incorporates propensity score weighting to create a composite hybrid randomized and external control arm, an approach preferred by the FDA over full replacement of a randomized control with an external control.

Changes of Healthy Brain Tissue after Salvage Radiotherapy of Glioblastoma Multiforme

Background Salvage radiotherapy (SRT) with photons is a valid treatment option for patients suffering from recurrent glioblastoma multiforme (GBM). However, the tolerance of healthy brain to ionizing radiation (IR) is limited. The aim of this study was to determine to what extent brain structures in the radiographically tumor-free hemisphere change after repeated radiotherapy. Methods Five of 26 patients treated with SRT for local recurrence of GBM were found to have magnetic resonance imaging (MRI) studies available for complete volumetric analysis before and after primary chemo-radiation and after SRT. Manual segmentation and joint segmentation (JS) based on a convolutional neural network were used for the segmentation of the grey matter, the white matter and the ventricles in T1 MRIs. Results Qualitative results of manual segmentation and JS were comparable. After primary chemo-radiation and SRT, the volume of the contralateral ventricles increased steadily by 1.3 to 4.75 % (SD +/- 2.8 %, R 2 = 0.82; p= &lt;0.01) with a manual segmentation and by 1.4 to 7.4 % (SD 2.1 %, R 2 = 0.48; p= 0.025) with JS. The volume of the cortex decreased by 3.4 – 7.3 % except in one patient, the cortex volume increased by 2.5% (SD +/- 2.9%, R 2 =0.18; p = 0.19) when measured manually. When measured with JS GM decreased by 1.0 to 7.4%, in one case it increased by 3.0% (SD = 3.2%, p = 0.22, R 2= 0.18). The white matter remained stable when assessed with manual segmentation (p = 0.84, R 2 = 0.004) or JS (p = 0.44, R 2 = 0.07). Conclusion SRT of relapsed GBM leads to continuous changes of the tumor-free contralateral brain by means of manual segmentation or JS. The cortex seems more susceptible to repeated RT compared to the white matter. Larger cohort studies and complementary functional analysis are encouraged.

Hemoglobin, albumin, lymphocytes and platelets (HALP) score is a useful predictor of survival in patients with recurrent glioblastoma multiforme treated with bevacizumab plus irinotecan

Purpose: We aimed to investigate whether the HALP score is a predictive marker in patients with recurrent GBM who were given bevacizumab plus irinotecan.Methods: We compared the survival of patients followed up in our clinic with the diagnosis of recurrent GBM and treated with bevacizumab plus irinotecan, according to HALP score.Results: Median PFS and OS were 4.5 (0.9-14.9) and 8 (0.9-21.3) months, respectively. The median PFS of the low HALP score group was 1.85 (1.3-3.37) months, and of the high HALP score group was 4.96 (0.9-14.9) months (p=0.03). The OS of the high HALP score group (9.63 [7.28-11.9]) was statistically higher compared with low HALP score group (2.26 [0.88-3.65]) (p<0.001). In univariate analysis HALP score was a significant prognostic factor; patients with low HALP score had a poorer prognosis than high HALP score (HR: 0.063, p<0.001). The multivariate analysis showed that HALP score (p=0.003), and residual tumor (p=0.029) were significant prognostic factors. In multivariate Cox regression analysis, low HALP score was a significant poor prognostic factor for OS compared with high HALP score (HR: 0.063, p<0.001).Conclusion: We showed that the HALP score at the start of treatment is an independent prognostic factor for PFS and OS in patients with recurrent GBM treated with bevacizumab plus irinotecan. The HALP score, which can be easily calculated by routine tests before chemotherapy, can be used as a predictive marker for bevacizumab treatment decision.