Recurrent High Grade Research Articles

MRI and [18F]FET PET for early response assessment of Nivolumab and Bevacizumab in patients with recurrent high grade astrocytic glioma

Abstract Background In the present study early response assessment by O-(2-[18F]fluoroethyl)-L-tyrosine (FET) positron emission tomography (PET) and contrast enhanced magnetic resonance imaging (MRI) were investigated in a phase II open-label single-centre study of nivolumab plus bevacizumab for recurrent high grade astrocytic glioma Methods Twenty patients with non-resectable first recurrence of high grade astrocytic glioma after EORTC/NCIC protocol underwent [18F]FET PET/MRI at baseline and after 2 cycles of treatment. Whole brain values of contrast enhancing volume on MRI (CEV), of mean (TBRmean) and maximal tumour-to-background ratio (TBRmax) and of metabolically active volume (MTV) on [18F]FET PET were obtained. Regional changes in [18F]FET uptake were assessed by parametric response mapping (PRM). Prediction of overall survival (OS) and response (OS>11 months) were assessed by Cox and receiver operating characteristic (ROC) analysis, respectively. Also, MRI (RANO 2.0) and PET based (PET RANO 1.0) response assessment criteria were compared. Results In ROC analysis responders were separated (p<0.05) from non-responders by lower MTV at follow-up (AUC 0.771, cut-off 18.3 ml), larger decrease in MTV (AUC 0.757, cut-off -5.3 ml), larger decrease in both TBRmax (AUC 0.814, cut-off -0.53) and relative TBRmax (AUC 0.829, cut-off -11%) and smaller PRM progressive volume (AUC 0.843, cut-off 4.0 ml). Change in CEV did not predict response. RANO 2.0 and PET RANO response assessment criteria had similar and only borderline prognostic value. Conclusion The study indicates that [18F]FET PET is superior to contrast enhanced MRI for early response assessment in patients with recurrent high grade astrocytic glioma treated with nivolumab and bevacizumab.

Oncolytic adenovirus MEM-288 encoding membrane-stable CD40L and IFNβ induces an anti-tumor immune response in high grade serous ovarian cancer

Single agent immune checkpoint inhibitors have been ineffective for patients with advanced stage and recurrent high grade serous ovarian cancer (HGSOC). Using pre-clinical models of HGSOC, we evaluated the anti-tumor and immune stimulatory effects of an oncolytic adenovirus, MEM-288. This conditionally replicative virus encodes a modified membrane stable CD40L and IFNβ. We demonstrated this virus successfully infects HGSOC cell lines and primary human ascites samples in vitro. We evaluated the anti-tumor and immunostimulatory activity in vivo in immune competent mouse models. Intraperitoneal delivery of MEM-288 decreased ascites and solid tumor burden compared to controls, and treatment generated a systemic anti-tumor immune response. The tumor microenvironment had a higher proportion of anti-tumor macrophages and decreased markers of angiogenesis. MEM-288 is a promising immunotherapy agent in HGSOC, with further pre-clinical studies required to understand the mechanism of action in the peritoneal microenvironment and clinical activity in combination with other therapies.

447MO A clinical study of the safety and efficacy of anlotinib hydrochloride combined with temozolomide dose density scheme for the treatment of recurrent high grade glioma

447MO A clinical study of the safety and efficacy of anlotinib hydrochloride combined with temozolomide dose density scheme for the treatment of recurrent high grade glioma

763: Hyperoxygenation and re-irradiation for recurrent high grade glioma: innovative therapeutic strategy

763: Hyperoxygenation and re-irradiation for recurrent high grade glioma: innovative therapeutic strategy

Gynecologic Cancer InterGroup CA125 response has a high negative predictive value for CHK1 inhibitor RECIST response in recurrent ovarian cancer

We investigated the association of CA125 response with prognosis and RECIST response/progressive disease (PD) criteria in recurrent high grade serous ovarian cancer (HGSOC) patients treated with a cell cycle checkpoint kinase 1 inhibitor (CHK1i), prexasertib. 81 patients had measurable disease per RECISTv1.1, of which 72 and 70 were measurable by Gynecologic Cancer InterGroup (GCIG) CA125 response and PD criteria, respectively. Univariate and multivariate analyses showed that GCIG CA125 response (n = 32) is associated with improved progression-free survival (PFS) and overall survival (OS) compared to no GCIG CA125 response (n = 40) (median PFS 8.0 vs. 3.5 months [HR: 0.30, 95% CI: 0.18–0.51, p < 0.0001]; median OS 19.8 vs. 10.0 months [HR: 0.38, 95% CI: 0.23–0.64, p < 0.001]) independent of BRCA mutation status, platinum-sensitivity, previous PARP inhibitor therapy, ECOG performance status, and FIGO stage. Notably, GCIG CA125 response had a high negative predictive value (NPV: 93%, 95% CI: 80–98), but poor positive predictive value (PPV: 53%, 95% CI: 35–71) in predicting RECIST response. CA125 PD criteria also showed poor concordance with RECIST PD (PPV 56%, 95% CI: 40–71; NPV 33%, 95% CI: 17–54). Therefore, serum CA125 may be useful as a highly accessible prognostic and predictive biomarker to CHK1i therapy in recurrent HGSOC.

Comparison between Reirradiation by Stereotactic Body Radiation Therapy and Moderately Hypofractionated Radiotherapy in Combination with Temozolomide for Treatment of Recurrent High Grade Glioma.

High grade glioma (HGG) is considered a lethal disease with a high recurrence rate. There is no standard of care in recurrent HGG. Many treatment options are present, such as resurgery, systemic therapy, and re-irradiation. Re-irradiation seems to be a promising option. In this study, we aimed at comparing the efficacy and toxicity of two re-irradiation protocols. Forty patients with recurrent HGG were randomized equally into two arms. Arm A received 30 Gy/10f/2w, and arm B received stereotactic body radiotherapy (SBRT) 30 Gy/5f/1w. Concurrent temozolamide (TMZ) was given in both arms. Median progression free survival (PFS) and overall survival (OS) were calculated, and brain MRI was done after 2 months of radiotherapy and then every 2 months, with documented toxicity using the Common Terminology of Adverse Events version 5 (CTCAE). The median follow-up time after the re-irradiation course was 11 months (range 8-15 months). The median PFS after recurrence was 6.4 months (95% CI 5.3-7.4), the median OS after recurrence was 8.6 months (95% CI 7.5-8.7), and the median total OS form date of diagnosis was 18.5 months (95% CI 17.3-19.8) among the included patients. There was a statistically significant difference in PFS favoring arm B, with a median PFS of 7.3 versus 6.2 months in arm A, with p values of 0.004. There was no statistically significant difference in in median OS (9.3 months in arm B versus 8.4 months in arm A) with p values of 0.088. All patients tolerated their treatment well, and acute and subacute G1-G2 toxicity, consisting of headache, malaise, and nausea, were recorded during and shortly after the end of the re-irradiation course. Re-irradiation in recurrent HGG by both protocols is safe and effective, with a significant improvement in PFS in SBRT arm but no significant improvement in OS.

PALC-03. MEDICAL AID IN DYING: EXPERIENCE IN THE CENTER FOR CANCER AND BLOOD DISORDERS AT CHILDREN’S HOSPITAL COLORADO

Abstract BACKGROUND Medical Aid in Dying (MAiD) is now legal in 10 US states and Washington, DC, allowing terminally ill patients to self-administer medications to peacefully end their life. There is little published on pediatric hospitals’ approach to young adult patients requesting MAiD. METHODS We review the two patients who have participated in MAiD at the Center for Cancer and Blood Disorders at Children’s Hospital Colorado (CHCO). We also explore publicly available Colorado MAiD statistics. RESULTS Between 2017 and 2022, there have been 1,090 prescriptions written for MAiD medication in Colorado, 5 of which were for patients aged 18-34 (0.5%). Two of these patients were treated at CHCO. Patient A was a 26 year old male with a CNS non-germinomatous germ cell tumor whose treatment was complicated by mucormycosis and severe engraftment syndrome. He relapsed 23 months after completing therapy. He had neurologic decline including ataxia and blindness, at which time he requested MAiD. Patient B was a 24 year old male with multiply recurrent IDH-mutant medullary high grade glioma. With metastatic progression, he had many tumor-related symptoms including dysphagia, dysarthria, and weakness impacting his activities of daily living, so he requested MAiD. Both patients had multidisciplinary care conferences with neuro-oncology, social work, ethics, psychology, and palliative care. After completing psychological evaluation and all steps required by law, they were prescribed DDAMP2 (digoxin 50 mg, diazepam 1 gram, morphine 15 grams, and propranolol 2 grams). Both patients took the medications and died peacefully. Barriers encountered included infrequency of MAiD requests leading to unclear policies and processes. CONCLUSIONS Young adults represent a small but important subset of those seeking MAiD prescriptions. Despite challenges, patients were able to receive MAiD without delay in a compassionate manner. Our experience may be applicable to other pediatric hospitals facing these requests.

Utility of circulating tumor DNA (ctDNA) from cerebrospinal fluid (CSF) for prognosis of patients with recurrent high grade glioma.

2010 Background: High-Grade Gliomas (HGGs) are the most aggressive primary brain tumors in adults and molecular characterization is crucial for diagnosis and optimal disease treatment. Due to the eloquent location of many HGGs, upfront or repeat tumor sampling may be sub-optimal. Hence, there is an urgent need to develop alternative, minimally invasive means to obtain diagnostic information and determine the expected clinical behavior. Here we report that circulating tumor DNA (ctDNA) from cerebrospinal fluid (CSF) can be used to identify disease defining genomic alterations and to track clonal evolution. Additionally, we demonstrate that detection of CSF ctDNA is positively correlated with leptomeningeal disease and overall survival suggesting that CSF ctDNA should be integrated into clinical decision making in the clinic. Methods: Our study includes 313 samples from 253 patients with recurrent glioma treated at Memorial Sloan Kettering Cancer Center who underwent CSF collection for routine clinical care and were sequenced using the MSK-IMPACT targeted clinical sequencing assay (468 and 505 genes). Alterations were classified as oncogenic based on OncoKB. 17% of genomic alterations detected were identified using a secondary bioinformatics analysis, following an informed approach with less stringent mutation calling criteria and Gaussian Mixture Model to call copy number events. CSF ctDNA positivity was determined by the presence of at least one oncogenic disease defining alteration or any shared alteration with the tumor. Results: Within this cohort, we found 193 CSF ctDNA positive (62%) and 120 CSF negative (38%) samples. Of note, CSF ctDNA positivity was the highest amongst histone mutant tumors with 94% CSF ctDNA positivity compared to 56% CSF ctDNA positivity for IDH-WT tumors. We noticed 44% of alterations shared between the tumor and the CSF, additionally, we noted considerable tumor evolution particularly within the growth signaling pathways (e.g. PDGFRA). The majority of the shared alterations were clonal, and we noticed the emergence of new clonal events in the CSF. Conclusions: Our cohort demonstrated that patients with positive CSF ctDNA had a significantly shorter overall survival compared to those who were CSF ctDNA negative (4.83 months vs 11.83 months, HR 2.1, p &lt; 0.001). In tandem with secondary clinical analysis, radiographic findings also correlated with CSF ctDNA positivity. Specifically, the presence of enhancing disease and contact of the tumor with the ventricular space were positively associated with detection of CSF ctDNA. Additionally, CSF ctDNA was associated with positive cytology in 21/21 cases (100%). With our improved bioinformatics pipeline, we hypothesize ctDNA from CSF may be used as a prognostic biomarker for survival, but confirmation requires further validation in a prospective study.

Multi-institutional study of reirradiation for recurrent high grade glioma.

2063 Background: Treatment options are limited for recurrent WHO Grade 3-4 glioma (HGG). Reirradiation (ReRT) is an option, but the ideal treatment regimen and the benefit of concurrent and adjuvant systemic therapy in the recurrent setting remains unclear. Methods: A retrospective review of patients with recurrent HGG treated with reRT was conducted at 12 institutions. Eligible patients were treated with two courses of fractionated RT (&gt;3 fractions) for glioma with the second course being for HGG. To estimate overall and progression free survival times, the Kaplan-Meier method was used. To assess the relationship between survival times and study variables, Cox proportional hazard regression models were used to calculate hazard ratios and the corresponding 95% confidence interval along with the p-value. SAS (version 9.4, Cary, NC, USA) was used for all analyses. P values &lt; 0.05 were assumed to be statistically significant. Results: 482 eligible patients were identified from 1997 to 2023. 235 (54%) had histologic confirmation of glioblastoma at reRT. The median age at reRT was 53.1 years and median KPS was 80. 196 patients (51%) were treated with reRT at their initial recurrence and 122 (30%) had an IDH mutation. The most common reRT dose and number of fractions were 35 Gy and 10 fractions. 192 patients (44%) and 95 (24%) received concurrent (conc) and adjuvant (adj) temozolomide (TMZ) respectively and 116 (27%) and 110 (28%) received conc and adj bevacizumab (BEV) respectively with reRT. Median OS and PFS were 9.8 and 5.3 months. OS (16.6 vs 7.8 months, HR 2.44 p &lt; 0.01) and PFS (8.6 vs 4.6 months, HR 1.85 p &lt; 0.01) were longer in patients with IDH mutations. Receipt of conc and adj TMZ with reRT was associated with improved OS (HR 0.67 p &lt; 0.01 and HR 0.49 p &lt; 0.01 respectively) and PFS (HR 0.66 p &lt;0.01 and HR 0.47 p &lt; 0.01 respectively). Receipt of concBEV with reRT was associated with worse OS (HR 1.66 p &lt; 0.01) but not PFS (HR 1.15 p = 0.28). AdjBEV was not associated with OS or PFS. Concurrent and adjTMZ were associated with improved OS ( p = 0.04 and &lt;0.01) and PFS ( p = 0.01 and &lt;0.01) for IDHwt tumors. In IDHmt tumors, concTMZ was associated with improved OS but not PFS ( p = 0.03 and 0.11), while adjTMZ was associated with improved OS and PFS ( p = 0.05 and &lt;0.01). Symptomatic adverse radiation effects and Grade 3 or greater neurologic toxicity were seen in 107 (25%) and 86 (20%) of patients respectively. Neither conc nor adjBEV nor TMZ were associated with symptomatic ARE. ConcBEV was associated with lower (13% vs 23%, p = 0.03) and concTMZ was associated with higher rates (25% vs 15%, p = 0.01) of Grade 3 or greater neurologic toxicity. Conclusions: The use of concurrent and adjuvant TMZ with reRT are associated with improved OS and PFS in recurrent HGG. OS and PFS are improved with conc and adjTMZ for IDHwt tumors, while there was no PFS benefit to concTMZ in IDHmt tumors. The rate of high grade neurologic toxicity was decreased with the use of concurrent BEV and increased with the use of concTMZ.

Abstract 3703: Utility of circulating tumor DNA (ctDNA) from cerebrospinal fluid (CSF) for prognosis of patients with recurrent high grade glioma

Abstract High-Grade Gliomas (HGGs) are the most aggressive primary brain tumors in adults and molecular characterization is crucial for diagnosis and optimal disease treatment. Due to the eloquent location of many HGGs, upfront or repeat tumor sampling may be sub-optimal. Hence, there is an urgent need to develop alternative, minimally-invasive means to obtain diagnostic information and determine the expected clinical behavior. Here we report that circulating tumor DNA (ctDNA) from cerebrospinal fluid (CSF) can be used to identify disease defining genomic alterations and to track clonal evolution. Additionally, we demonstrate that detection of CSF ctDNA is positively correlated with leptomeningeal disease and overall survival suggesting that CSF ctDNA should be integrated into clinical decision making in the clinic. Our study includes 315 samples from 254 patients with recurrent glioma treated at Memorial Sloan Kettering Cancer Center who underwent CSF collection for routine clinical care and were sequenced using the MSK-IMPACT targeted clinical sequencing assay (468 and 505 genes). Alterations were classified as oncogenic based on OncoKB. 23% of genomic alterations detected were identified using a secondary bioinformatics analysis, following an informed approach with less stringent mutation calling criteria and Gaussian Mixture Model to call copy number events. CSF ctDNA positivity was determined by the presence of at least one oncogenic disease defining alteration or any shared alteration with the tumor. Within this cohort, we found 198 CSF ctDNA positive (63%) and 117 CSF negative (37%) samples. Of note, CSF ctDNA positivity was the highest amongst histone mutant tumors with 94% CSF ctDNA positivity compared to 56% CSF ctDNA positivity for IDH-WT tumors. We noticed considerable evolution of the cancer genome in patients with sequential biopsies with only 35% of alterations shared between the tumor and the CSF, in particular within the growth signaling pathways (e.g. PDGFRA). The majority of the shared alterations were clonal, and we noticed the emergence of new clonal events in the CSF. Our cohort demonstrated that patients with positive CSF ctDNA had a significantly shorter overall survival compared to those who were CSF ctDNA negative (4.83 months vs 11.83 months, HR 2.1, p &amp;lt; 0.001). In tandem with secondary clinical analysis, radiographic findings also correlated with CSF ctDNA positivity. Specifically, the presence of enhancing disease and contact of the tumor with the ventricular space were positively associated with detection of CSF ctDNA. Additionally, CSF ctDNA was associated with positive cytology in 21/21 cases (100%). With our improved bioinformatics pipeline we hypothesize ctDNA from CSF may be used as a prognostic biomarker for survival, but confirmation requires further validation in a prospective study. Citation Format: Bridget M. Holle, Subhiksha Nandakumar, Christoph Kreitzer, Timothy Song, Marlene Tartaro, Charli Ann J. Hertz, Johnathan Rafailov, Carl Campos, Anne S. Reiner, Robert Young, Alicia Meng, Luca Pasquini, A. Rose Brannon, Nicholas D. Socci, Maria E. Arcila, David B. Solit, Michael F. Berger, Nikolaus Schultz, Ingo K. Mellinghoff, Alexandra M. Miller. Utility of circulating tumor DNA (ctDNA) from cerebrospinal fluid (CSF) for prognosis of patients with recurrent high grade glioma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3703.

Abstract 575: Identification of SORL1 as a key regulator of chemoresistance in ovarian cancer

Abstract This study aimed to understand the molecular mechanism of platinum chemoresistance in recurrent ovarian tumors with a focus on the SORL1-regulated pathways. SORL1 is an intracellular sorting receptor that binds to HER2 in breast cancer; this promotes HER2 recycling to the cell surface, which ultimately impacts the progression and treatment of breast cancer. The role of SORL1 in ovarian cancer has not been extensively studied. Method: RNA was extracted from 15 pairs of matched primary and recurrent high grade serous ovarian tumors collected from patients. Human transcriptomic microarray was used to identify the differentially expressed genes. The identified genes were validated by RT-QPCR and western blot in five ovarian cancer cell lines that were treated or untreated with carboplatin. To study the effects of identified target gene SORL1, overexpression and knockdown in ovarian cancer cell lines were established using SORL1 plasmid and shRNA. Proliferation and response to carboplatin were analyzed using celltiter Glo and caspase-3/7 activity assays respectively. EGFR and FGFR4 were identified as the interacting proteins of SORL1 in ovarian cancer cells through FGF1 and EGF1 treatment and co-immunoprecipitation. A proximity ligation assay was performed to validate their interactions. Finally, a xenograft mouse model was used to compare the tumor forming abilities and the response to carboplatin of SORL1-knockdown ovarian cancer cells and the control cancer cells in vivo. Protein expression of SORL1, EGFR, and FGFR4 in the collected tumors was determined via western blot. Result: Transcriptomic analysis of matched human primary and recurrent ovarian tumors identified SORL1 as an upregulated gene in recurrent tumors compared to primary samples. SORL1 expression was also upregulated in ovarian cancer cells surviving carboplatin treatment. Proliferation assays demonstrated that SORL1-overexpressing and knockdown cell lines had increased and inhibited proliferative capabilities respectively. Caspase-3 activity assays showed that SORL1-overexpressing and knockdown cell lines had reduced and increased sensitivity to carboplatin treatment respectively. SORL1 was found to bind to and promote the expression of EGFR and FGFR4. When injected subcutaneously into nude mice, SORL1-knockdown cells had reduced tumor forming capabilities and increased sensitivity to carboplatin. SORL1-knockdown caused the tumors to express lower levels of SORL1, EGFR, and FGFR4 proteins in comparison with the control tumors. Conclusion: This study demonstrates that SORL1 regulates the EGFR and FGF4 pathways to promote the growth and carboplatin resistance of ovarian cancer cells. Targeting this pathway has potential to aid in the treatment of platinum-resistant ovarian cancer. Citation Format: Miranda Mansolf, Ziyan Jian, Fangfang Bi, Tobias M. Hartwich, Yang Yang-Hartwich. Identification of SORL1 as a key regulator of chemoresistance in ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 575.

Amino acid PET vs. RANO MRI for prediction of overall survival in patients with recurrent high grade glioma under bevacizumab therapy.

To summarize evidence on the comparative value of amino acid (AA) PET and conventional MRI for prediction of overall survival (OS) in patients with recurrent high grade glioma (rHGG) under bevacizumab therapy. Medical databases were screened for studies with individual data on OS, follow-up MRI, and PET findings in the same patient. MRI images were assessed according to the RANO criteria. A receiver operating characteristic curve analysis was used to predict OS at 9 months. Five studies with a total of 72 patients were included. Median OS was significantly lower in the PET-positive than in the PET-negative group. PET findings predicted OS with a pooled sensitivity and specificity of 76% and 71%, respectively. Corresponding values for MRI were 32% and 82%. Area under the curve and sensitivity were significantly higher for PET than for MRI. For monitoring of patients with rHGG under bevacizumab therapy, AA-PET should be preferred over RANO MRI.

Dengue fever: a case study review, data analysis and management

The dengue fever which caused by vector aedes mosquito, which is an arboviral infection that can cause anything from a mild flu-like sickness to hemorrhagic symptoms. The case of a 35-year-old man with dengue fever and accompanying hemorrhagic symptoms is presented here. In this case the patient presented with melena as a complication of dengue with recurrent high grade fever.In order to clarify the diagnosis, and treatment of hemorrhagic symptoms in dengue fever, we also carried out a thorough study of the literature. Leading a nation towards wealth, advancement, and economic expansion while addressing various issues and worries arising from worldwide circumstances is the primary goal of any nation. Any sickness that appears suddenly defies national economies and health care systems.

Evaluation of ex vivo drug combination optimization platform in recurrent high grade astrocytic glioma: An interventional, non-randomized, open-label trial protocol.

High grade astrocytic glioma (HGG) is a lethal solid malignancy with high recurrence rates and limited survival. While several cytotoxic agents have demonstrated efficacy against HGG, drug sensitivity testing platforms to aid in therapy selection are lacking. Patient-derived organoids (PDOs) have been shown to faithfully preserve the biological characteristics of several cancer types including HGG, and coupled with the experimental-analytical hybrid platform Quadratic Phenotypic Optimization Platform (QPOP) which evaluates therapeutic sensitivity at a patient-specific level, may aid as a tool for personalized medical decisions to improve treatment outcomes for HGG patients. This is an interventional, non-randomized, open-label study, which aims to enroll 10 patients who will receive QPOP-guided chemotherapy at the time of first HGG recurrence following progression on standard first-line therapy. At the initial presentation of HGG, tumor will be harvested for primary PDO generation during the first biopsy/surgery. At the point of tumor recurrence, patients will be enrolled onto the main study to receive systemic therapy as second-line treatment. Subjects who undergo surgery at the time of recurrence will have a second harvest of tissue for PDO generation. Established PDOs will be subject to QPOP analyses to determine their therapeutic sensitivities to specific panels of drugs. A QPOP-guided treatment selection algorithm will then be used to select the most appropriate drug combination. The primary endpoint of the study is six-month progression-free survival. The secondary endpoints include twelve-month overall survival, RANO criteria and toxicities. In our radiological biomarker sub-study, we plan to evaluate novel radiopharmaceutical-based neuroimaging in determining blood-brain barrier permeability and to assess in vivo drug effects on tumor vasculature over time. This trial was registered on 8th September 2022 with ClinicalTrials.gov Identifier: NCT05532397.

Focused ultrasound combined with radiotherapy for malignant brain tumor: a preclinical and clinical study.

Blood-brain barrier (BBB) remains to be the major obstacle to conquer in treating patients with malignant brain tumors. Radiation therapy (RT), despite being the mainstay adjuvant modality regardless of BBB, the effect of radiation induced cell death is hindered by the hypoxic microenvironment. Focused ultrasound (FUS) combined with systemic microbubbles has been shown not only to open BBB but also potentially increased regional perfusion. However, no clinical study has investigated the combination of RT with FUS-BBB opening (RT-FUS). We aimed to provide preclinical evidence of RT-FUS combination in GBM animal model, and to report an interim analysis of an ongoing single arm, prospective, pilot study (NCT01628406) of combining RT-FUS for recurrent malignant high grade glioma patients, of whom re-RT was considered for disease control. In both preclinical and clinical studies, FUS-BBB opening was conducted within 2h before RT. Treatment responses were evaluated by objective response rate (ORR) using magnetic resonance imaging, progression free survival, and overall survival, and adverse events (AE) in clinical study. Survival analysis was performed in preclinical study and descriptive analysis was performed in clinical study. In mouse GBM model, the survival analysis showed RT-FUS (2Gy) group was significantly longer than RT (2Gy) group and control, but not RT (5Gy) group. In the pilot clinical trial, an interim analysis of six recurrent malignant high grade glioma patients underwent a total of 24 RT-FUS treatments was presented. Three patients had rapid disease progression at a mean of 33days after RT-FUS, while another three patients had at least stable disease (mean 323days) after RT-FUS with or without salvage chemotherapy or target therapy. One patient had partial response after RT-FUS, making the ORR of 16.7%. There was no FUS-related AEs, but one (16.7%) re-RT-related grade three radiation necrosis. Reirradiation is becoming an option after disease recurrence for both primary and secondary malignant brain tumors since systemic therapy significantly prolongs survival in cancer patients. The mechanism behind the synergistic effect of RT-FUS in preclinical model needs further study. The clinical evidence from the interim analysis of an ongoing clinical trial (NCT01628406) showed a combination of RT-FUS was safe (no FUS-related adverse effect). A comprehensive analysis of radiation dosimetry and FUS energy distribution is expected after completing the final recruitment.

Multi-Institutional Report of Re-Irradiation for Recurrent High-Grade Glioma

Significant heterogeneity exists with regards to prior published reports of re-irradiation (re-RT) in patients with recurrent high grade glioma (HGG). A multi-institutional database of 10 academic centers across the United States was created to analyze prognostic outcomes for re-RT for recurrent HGG, which included WHO Grade III and Grade IV tumors. Patients with HGG who had initially received standard radiotherapy (RT) and were subsequently treated with a course of re-RT at recurrence were included in the study. Factors assessed to delineate a significant association with overall survival (OS) and toxicity included age, KPS, number of relapses, dose, use of bevacizumab (BEV) or temozolomide (TMZ), time from prior RT, histology, RT target, re-RT target> 5cm and extent of resection, and MGMT methylation status. The Kaplan-Meier Method was used to estimate OS. Cox proportional hazards regression models were used to identify factors associated with OS. Toxicity outcomes were assessed using logistic regression. Significance was assumed if p<0.05. Data management and decision management software were used for all analyses. Between 2001 and 2022, 280 patients from 10 academic institutions were treated with re-RT for diagnosis of recurrent HGG. 133 patients (71.1%) had a histologic glioblastoma (GBM) at the time of re-RT, with the remainder having Grade 3 gliomas. Median dose delivered at re-RT was 47 Gy BED10 (IQR 47 - 53 Gy BED10), with the most common regimen being 35 Gy in 10 fractions. 83 patients (56%) had GTV greater than 5 cm treated with re-RT. 183 patients (79%) received concurrent systemic therapy, including 95 (41%) who received concurrent TMZ and 86 (45%) who received concurrent BEV. Median OS for the entire cohort was 10 months. Increasing dose at re-RT was associated with improved OS (OR 0.80 95% CI 0.67-0.95, p = 0.10 per 10 Gy BED10), as was dose greater than 47 Gy BED10, which is equivalent to 35 Gy in 10 fractions (OR 0.70, 95% CI 0.54-0.91). Concurrent TMZ was also associated with improved OS (OR 0.68, 95% CI 0.46-0.83, p < 0.01). 32/143 (22%) patients evaluable for toxicity experienced Grade 2 or greater adverse radiation effect (ARE). Use of BEV was associated with decreased toxicity (OR 0.45, 95% CI 0.21-0.98, p = 0.05). Dose at re-RT (OR 1.07 per 10 Gy BED10, p = 0.78), a GTV > 5cm (OR 1.39, p = 0.44), and the use of concurrent TMZ (OR 1.90, p = 0.10) were not associated with Grade 2 or greater ARE. Higher dose of re-RT and use of concurrent TMZ led to improved OS in recurrent HGG patients without an associated increased rate of ARE. Use of BEV decreased the likelihood of Grade 2 or greater ARE in the re-RT setting for these recurrent HGG patients.

Usefulness of Photodynamic Diagnosis with Talaporfin Sodium in Surgery for Recurrent High Grade Glioma

Usefulness of Photodynamic Diagnosis with Talaporfin Sodium in Surgery for Recurrent High Grade Glioma

A phase 1/2 open-label, multicenter, dose escalation and expansion study of AVB-001, an intraperitoneally administered, cell-generated, human IL-2 immunotherapy in patients with platinum-resistant, high-grade, serous adenocarcinoma of the ovary, primary peritoneum, or fallopian tube.

TPS5616 Background: The potential of cytokines as cancer therapeutics has been limited by short half-life and severe adverse effects associated with high systemic exposure when delivered intravenously. Many strategies are being explored to overcome these limitations. A locoregional delivery approach to achieve high sustained local concentrations in the tumor microenvironment with minimal systemic exposure could widen the therapeutic window. Early experience with free recombinant human IL2 (rhIL-2) given intraperitoneally (IP) showed meaningful clinical activity in relapsed ovarian cancer. Still, the cumbersome delivery procedure requiring indwelling catheters and need for high volume IP infusions leading to frequent complications and poor patient compliance limited the utility of this approach. To overcome these shortcomings, we developed a clinically translatable localized delivery LOCOcyte platform composed of polymer encapsulated allogeneic epithelial cells engineered to produce immune effector molecules for local delivery with temporal regulation. The first product, AVB-001, produces native hIL-2, for the treatment of ovarian cancer and other peritoneal malignancies. IP AVB-001 inhibited tumor growth and improved survival in an in vivo ID8 ovarian cancer murine model. Sustained IL-2 production with well tolerated high IP concentrations were achieved, with &gt;100x differential concentration vs. systemic blood levels in both mice and non-human primates. Strong local and systemic immune activating effects, optimized T cell profile and immune memory were observed without concomitant increase of T regs. The first in human study of AVB-001 in patients with advanced ovarian cancer (NCT05538624) is described here. Methods: Part 1 dose escalation exploring 4 ascending dose levels (capsules target production of 0.6, 1.2, 2.4, and 3.6 ug hIL2/kg/d) with a Bayesian Optimal Interval 3+3 design, in patients with recurrent high grade serous adenocarcinoma of the ovary, primary peritoneum, or fallopian tube. A minimum of 12 and up to 24 patients will be enrolled to receive one dose of AVB-001 administered IP. The primary objective is to evaluate safety (Incidence and severity of adverse events per NCI CTCAE v5.0), tolerability, and feasibility of delivering AVB-001 IP, and establish the RP2D. Secondary objectives include assessment of antitumor activity (RECIST v1.1, iRECIST), pharmacokinetics, and pharmacodynamic correlates of immune activation. Part 2 will enroll 20 patients at the RP2D with efficacy as the primary objective. This multicenter study will be conducted at 5 sites, currently two sites are open. The first patient was dosed in December 2022. Recruitment in dose level 1 cohort continues. Clinical trial information: NCT05538624 .

Response to subsequent platinum-based chemotherapy post PARP inhibitor in recurrent epithelial ovarian cancer.

5578 Background: Maintenance therapy with PARP inhibitors (PARPi) can increase progression free survival (PFS) for recurrent or metastatic platinum-sensitive epithelial ovarian cancer (EOC). Little is known about disease trajectory following treatment with these agents, though some evidence suggests a decreased response to subsequent platinum-based chemotherapy. This retrospective cohort study assessed real-world response rates to platinum-based chemotherapy for recurrent high grade EOC following treatment with a PARPi. Methods: All patients prescribed a PARPi as maintenance therapy for recurrent or metastatic EOC at the Ottawa Regional Cancer Center (ORCC) from September 2017 to May 2022 were included. PFS following penultimate therapy (line of therapy preceding PARPi initiation) as well as the PFS following subsequent platinum-based chemotherapy in patients with disease progression more than 6 months after penultimate therapy were calculated. Incidence of platinum resistance in patients with disease progression following PARPi therapy was determined. Results: 91 patients were included in the analysis including 54 patients on niraparib and 36 patients on olaparib. Follow-up after initiation of PARPi ranged from 4.6 months to 62.0 months with a median of 16.3 months. 54 (59.3%) of patients experienced disease progression after initiation of PARPi therapy, including 10 (11.0%) who progressed within 6 months of their penultimate therapy. Of the 44 patients who experienced disease progression more than 6 months following penultimate therapy, 32 (72.7%) were rechallenged with platinum-based chemotherapy. Of these, 16 (50.0%) experienced further disease progression with 14 (43.8%) progressing within 6 months of their platinum rechallenge. Median PFS following platinum rechallenge was 4.4 months (from 0.8 months to 34.9 months), significantly lower than previous reports. Conclusions: Patients who experienced disease progression following PARPi therapy showed a poor response to subsequent platinum-based chemotherapy, even when progression occurred more than 6 months after completion of their penultimate platinum-based chemotherapy. This supports the theory that PARPi resistance may be a surrogate for platinum resistance and raises concern for possible contribution of PARPi in the induction of platinum resistance in recurrent EOC.

Abstract CT122: A phase 1/2 open-label, multicenter, dose escalation and expansion study of AVB-001, an intraperitoneally administered, cell-generated, human IL-2 immunotherapy in patients with platinum-resistant, high-grade, serous adenocarcinoma of the ovary, primary peritoneum, or fallopian tube

Abstract Background: The potential of cytokines as cancer therapeutics has been limited by short half-life and severe adverse effects associated with high systemic exposure when delivered intravenously. Many strategies are being explored to overcome these limitations. A locoregional delivery approach to achieve high sustained local concentrations in the tumor microenvironment with minimal systemic exposure could widen the therapeutic window. Early experience with free recombinant human IL2 (rhIL-2) given intraperitoneally (IP) showed meaningful clinical activity in relapsed ovarian cancer. Still, the cumbersome delivery procedure requiring indwelling catheters and need for high volume IP infusions leading to frequent complications and poor patient compliance limited the utility of this approach. To overcome these shortcomings, we developed a clinically translatable localized delivery LOCOcyteTM platform composed of polymer encapsulated allogeneic epithelial cells engineered to produce immune effector molecules for local delivery with temporal regulation. The first product, AVB-001, produces native hIL-2, for the treatment of ovarian cancer and other peritoneal malignancies. IP AVB-001 inhibited tumor growth and improved survival in an in vivo ID8 ovarian cancer murine model. Sustained IL-2 production with well tolerated high IP concentrations were achieved, with &amp;gt;100x differential concentration vs. systemic blood levels in both mice and non-human primates. Strong local and systemic immune activating effects, optimized T cell profile and immune memory were observed without concomitant increase of T regs. The first in human study of AVB-001 in patients with advanced ovarian cancer (NCT05538624) is described here. Methods: Part 1 dose escalation exploring 4 ascending dose levels (capsules target production of 0.6, 1.2, 2.4, and 3.6 ug hIL2/kg/d) with a Bayesian Optimal Interval 3+3 design, in patients with recurrent high grade serous adenocarcinoma of the ovary, primary peritoneum, or fallopian tube. A minimum of 12 and up to 24 patients will be enrolled to receive one dose of AVB-001 administered IP. The primary objective is to evaluate safety (Incidence and severity of adverse events per NCI CTCAE v5.0), tolerability, and feasibility of delivering AVB-001 IP, and establish the RP2D. Secondary objectives include assessment of antitumor activity (RECIST v1.1, iRECIST), pharmacokinetics, and pharmacodynamic correlates of immune activation. Part 2 will enroll 20 patients at the RP2D with efficacy as the primary objective. This multicenter study will be conducted at 5 sites, currently one site is open. The first patient was dosed in December 2022. Recruitment in dose level 1 cohort continues. Citation Format: Shannon N. Westin, Travis Sims, Karen Andreas, Eric Soliman, Manish Jain, Claudio A. Dansky Ullmann, Amir A. Jazaeri. A phase 1/2 open-label, multicenter, dose escalation and expansion study of AVB-001, an intraperitoneally administered, cell-generated, human IL-2 immunotherapy in patients with platinum-resistant, high-grade, serous adenocarcinoma of the ovary, primary peritoneum, or fallopian tube [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr CT122.