Weinberg, Jeffrey S.

TPS2094 Background: Liquid biopsy in glioblastoma (GBM) is hindered by a lack of requisite circulating tumor (ct) and cell-free (cf) DNA levels in blood due to the blood-brain barrier (BBB). This limits the identification of blood-based tumor biomarkers along with the development and use of biomarker-driven systemic therapies. Low intensity focused ultrasound combined with intravenously administered microbubble oscillators (MB-FUS), leads to non-invasive BBB opening. This trial aims to evaluate the utility of LIFU for bolstering blood ctDNA and cfDNA for enhance liquid biopsy in patients with GBM. Methods: LIBERATE is an ongoing, prospective, multi-center, self-controlled, pivotal trial evaluating safety and technical efficacy of transcranial MR-guided MB-FUS for increasing blood ctDNA and cfDNA levels in adults, aged 18-80 years with GBM. Patients with suspected GBM planned for tumor biopsy or resection at 17 centers in US and Canada are being enrolled. Patients with multifocal tumors or tumors arising from deep midline, thalamus, cerebellum, or brainstem are excluded. Patients are administered IV microbubbles for enhanced sonication, after which MR-guided BBB opening using a 220 kHz device, with 1024-element phased array transducer, is performed with real-time acoustic feedback control for effective cavitation. Pre- and post-procedure, phlebotomy and MRI brain are done. Patients are offered optional 2 nd procedure during adjuvant chemotherapy phase if willing. Primary efficacy endpoint is correlation between biomarker patterns in tumor tissue collected during surgery/biopsy and blood collected following MB-FUS procedure. Confirmatory secondary efficacy endpoint is ratio between greatest yield of cfDNA in blood post-MB-FUS compared to cfDNA level in blood pre-MB-FUS. The primary study hypothesis is that agreement rate on biomarker pattern between resected/biopsied tumor tissue and blood is > 70%. The secondary hypothesis is that MB-FUS BBBO leads to a ≥2-fold rise in blood cfDNA. Assuming the true agreement rate expected is 89%, a sample of N = 50 patients will provide 90% power to meet the primary endpoint (Exact test, Binomial Proportion, one-sided Alpha = 0.025). Exploratory endpoints include (1) sensitivity of detection of known specific somatic mutations in ctDNA from blood samples collected before and after MB-FUS, (2) estimation of ctDNA levels in samples collected at 30-minutes, 1-hour, 2-hour, and 3-hour post-MB-FUS to determine time of greatest yield, (3) correlation of MRI parameters related to grading of BBB opening and ctDNA-based biomarkers from post-MB-FUS blood samples, (4) biomarker correlation between plasma cfDNA sampled during adjuvant chemotherapy phase and tumor tissue harvested at surgery. Patient enrollment commenced in 2022 and is ongoing (NCT05383872). Clinical trial information: NCT05383872 .

Abstract BACKGROUND Liquid biopsy in glioblastoma (GBM) is hindered by insufficient requisite circulating-tumor (ct) and cell-free (cf) DNA in blood due to blood-brain barrier (BBB). This limits the identification of blood-based tumor biomarkers along with biomarker-driven systemic therapies. Real-time image-guided low-intensity focused ultrasound (LIFU) plus IV microbubble oscillators, leads to non-invasive BBB disruption. METHODS LIBERATE is an ongoing, prospective, multi-center, self-controlled, pivotal trial investigating safety and technical efficacy of LIFU-based BBB disruption for increasing blood ctDNA and cfDNA levels in adult GBM patients (aged 18-80 years). Patients with suspected GBM planned for biopsy/resection at ten US centers are being enrolled. Patients with multifocal tumors or tumors arising from deep midline, thalamus, cerebellum, or brainstem are excluded. Patients are administered IV microbubbles for enhanced sonication effects, after which MR-guided BBB disruption using 220kHz LIFU device is performed with real-time acoustic-feedback-control for effective microbubble activation. Pre- and post-LIFU, phlebotomy and MRI brain are performed. Primary study endpoint is defined, per subject, as ratio between their blood cfDNA level 1-hour post-LIFU procedure compared to blood cfDNA pre-procedure. Primary study hypothesis is that BBB disruption leads to ≥2-fold rise in blood cfDNA. Secondary hypothesis is that there exists ≥75% agreement between biomarker pattern in blood cfDNA sample obtained 1-hour post-LIFU and biomarker pattern in tumor tissue obtained later. Trial is powered to evaluate both primary and secondary hypotheses. Based on assumed true agreement rate of 91% and one-sided alpha=0.025, an exact test for binomial proportions provides N=50 with 84% power for secondary hypothesis. Exploratory endpoints include (1) sensitivity of detection of specific somatic mutations in ctDNA from blood collected pre- and post-LIFU, (2) ctDNA estimation in samples collected at 30-minutes, 1-hour, 2-hour, and 3-hour post-LIFU to determine time of greatest yield, (3) correlation of MRI parameters related to grading of BBB disruption and ctDNA-based biomarkers from post-LIFU blood samples. Patient enrollment commenced in 2022 and remains ongoing (NCT05383872).

Abstract BACKGROUND Liquid biopsy in glioblastoma (GBM) is hindered by a lack of requisite circulating tumor (ct) and cell-free (cf) DNA levels in blood due to the blood-brain barrier (BBB). This limits the identification of blood-based tumor biomarkers along with the development and use of biomarker-driven systemic therapies. Real-time image-guided low intensity focused ultrasound (LIFU) combined with intravenously administered microbubble oscillators, leads to non-invasive disruption of the BBB. This trial aims to evaluate the utility of LIFU for boosting blood ctDNA and cfDNA for enhanced liquid biopsy in GBM patients. MATERIAL AND METHODS LIBERATE is an ongoing, prospective, multi-center, self-controlled, pivotal trial evaluating safety and technical efficacy of LIFU-based BBB disruption for increasing blood ctDNA and cfDNA levels in adults, aged 18-80 years with GBM. Patients with suspected GBM planned for tumor biopsy or resection at ten centers in the US are being enrolled. Patients with multifocal tumors or tumors arising from deep midline, thalamus, cerebellum, or brainstem are excluded. Patients are administered IV microbubbles for enhanced sonication effects, after which MR-guided BBB disruption using a 220 kHz LIFU device is performed with real-time acoustic feedback control for effective microbubble activation. Before and after procedure, phlebotomy and MRI brain are performed to evaluate outcomes. Primary study endpoint is defined, per subject, as ratio between their cfDNA level in blood 1-hour post-LIFU procedure compared to cfDNA level in blood pre-procedure. Primary study hypothesis is that BBB disruption with LIFU leads to a ≥2-fold rise in blood cfDNA. The secondary hypothesis is that there exists ≥75% agreement between biomarker pattern in blood cfDNA sample obtained 1-hour post-LIFU and the biomarker pattern in tumor tissue obtained later. The trial has been powered to evaluate both primary and secondary hypotheses. Based on an assumed true agreement rate of 91% and a one-sided alpha of 0.025, an exact test for binomial proportions provides a sample of N = 50 with 84% power for the secondary hypothesis. Exploratory endpoints include (1) sensitivity of detection of known specific somatic mutations in ctDNA from blood samples collected before and after LIFU, (2) estimation of ctDNA levels post-LIFU in samples collected at 30 minutes, 1 hour, 2 hour, and 3 hour to determine the time of greatest yield, (3) correlation of MRI parameters related to grading of BBB disruption and ctDNA-based biomarkers from post-LIFU blood samples. RESULTS Patient enrollment commenced in 2022, and 22 patients have been recruited by 05/2024. CONCLUSION Findings from this trial will be critical to liquid biopsy in GBM (Clinical trial information: NCT05383872).

Abstract BACKGROUND Liquid biopsy in glioblastoma (GBM) is hindered by a lack of requisite circulating-free DNA (cfDNA) blood levels in due to the blood-brain barrier (BBB). Real-time image-guided low-intensity focused ultrasound (LIFU) with intravenously administered microbubble oscillators non-invasively causes BBB disruption (BBBD). This clinical trial aimed to evaluate the utility of LIFU for increasing cfDNA in blood for liquid biopsy in GBM. METHODS LIBERATE is an ongoing, prospective, multi-center, self-controlled, ongoing, pivotal trial evaluating the safety and technical efficacy of LIFU for BBBD to increase cfDNA in blood for GBM. Patients aged 18-80 years with suspected GBM planned for tumor biopsy or resection at ten centers in the US are being included. Patients are administered intravenous oscillating microbubbles for enhancing sonication, after which MR-guided BBBD using 220 kHz LIFU device is performed, with real-time acoustic feedback for effective sonication. Pre- and post-procedure, phlebotomies, and MRI brain are performed. The primary study endpoint is defined, per subject, as the ratio between cfDNA levels in blood 1-hour post-LIFU procedure compared to cfDNA level in blood pre-procedure. The primary study hypothesis is that BBBD with LIFU leads to ≥2-fold increase in cfDNA in blood. The secondary hypothesis is that there exists ≥75% concordance between biomarker patterns in the cfDNA sample from 1-hour post-LIFU sample and tumor tissue obtained later. Exploratory endpoints include (1) sensitivity of detection of known somatic mutations in cfDNA from blood samples collected before and after LIFU, (2) estimation of cfDNA levels in samples collected at 30 minutes, 1 hour, 2 hours, and 3 hours post-LIFU to determine the time of greatest yield, (3) correlation of MRI parameters related to BBBD grading and biomarkers in cfDNA from post-LIFU samples. Patient enrollment commenced in 2022, and 13 patients have been recruited by 06/09/2023. Clinical trial information: NCT05383872.

Abstract Brain metastases are a challenging manifestation of renal cell carcinoma. We have a limited understanding of brain metastasis tumor and immune biology, drivers of resistance to systemic treatment, and their overall poor prognosis. Current data support a multimodal treatment strategy with radiation treatment and/or surgery. Nonetheless, the optimal approach for the management of brain metastases from renal cell carcinoma remains unclear. To improve patient care, the authors sought to standardize practical management strategies. They performed an unstructured literature review and elaborated on the current management strategies through an international group of experts from different disciplines assembled via the network of the International Kidney Cancer Coalition. Experts from different disciplines were administered a survey to answer questions related to current challenges and unmet patient needs. On the basis of the integrated approach of literature review and survey study results, the authors built algorithms for the management of single and multiple brain metastases in patients with renal cell carcinoma. The literature review, consensus statements, and algorithms presented in this report can serve as a framework guiding treatment decisions for patients. CA Cancer J Clin. 2022;72:454‐489.

Abstract Purpose To provide guidance to clinicians regarding therapy for patients with brain metastases from solid tumors. Methods ASCO convened an Expert Panel and conducted a systematic review of the literature. Results Thirty-two randomized trials published in 2008 or later met eligibility criteria and form the primary evidentiary base. Recommendations Surgery is a reasonable option for patients with brain metastases. Patients with large tumors with mass effect are more likely to benefit than those with multiple brain metastases and/or uncontrolled systemic disease. Patients with symptomatic brain metastases should receive local therapy regardless of the systemic therapy used. For patients with asymptomatic brain metastases, local therapy should not be deferred unless deferral is specifically recommended in this guideline. The decision to defer local therapy should be based on a multidisciplinary discussion of the potential benefits and harms that the patient may experience. Several regimens were recommended for non–small-cell lung cancer, breast cancer, and melanoma. For patients with asymptomatic brain metastases and no systemic therapy options, stereotactic radiosurgery (SRS) alone should be offered to patients with one to four unresected brain metastases, excluding small-cell lung carcinoma. SRS alone to the surgical cavity should be offered to patients with one to two resected brain metastases. SRS, whole brain radiation therapy, or their combination are reasonable options for other patients. Memantine and hippocampal avoidance should be offered to patients who receive whole brain radiation therapy and have no hippocampal lesions and 4 months or more expected survival. Patients with asymptomatic brain metastases with either Karnofsky Performance Status ≤ 50 or Karnofsky Performance Status < 70 with no systemic therapy options do not derive benefit from radiation therapy. Additional information is available at www.asco.org/neurooncology-guidelines.

PURPOSE To provide guidance to clinicians regarding therapy for patients with brain metastases from solid tumors. METHODS ASCO convened an Expert Panel and conducted a systematic review of the literature. RESULTS Thirty-two randomized trials published in 2008 or later met eligibility criteria and form the primary evidentiary base. RECOMMENDATIONS Surgery is a reasonable option for patients with brain metastases. Patients with large tumors with mass effect are more likely to benefit than those with multiple brain metastases and/or uncontrolled systemic disease. Patients with symptomatic brain metastases should receive local therapy regardless of the systemic therapy used. For patients with asymptomatic brain metastases, local therapy should not be deferred unless deferral is specifically recommended in this guideline. The decision to defer local therapy should be based on a multidisciplinary discussion of the potential benefits and harms that the patient may experience. Several regimens were recommended for non–small-cell lung cancer, breast cancer, and melanoma. For patients with asymptomatic brain metastases and no systemic therapy options, stereotactic radiosurgery (SRS) alone should be offered to patients with one to four unresected brain metastases, excluding small-cell lung carcinoma. SRS alone to the surgical cavity should be offered to patients with one to two resected brain metastases. SRS, whole brain radiation therapy, or their combination are reasonable options for other patients. Memantine and hippocampal avoidance should be offered to patients who receive whole brain radiation therapy and have no hippocampal lesions and 4 months or more expected survival. Patients with asymptomatic brain metastases with either Karnofsky Performance Status ≤ 50 or Karnofsky Performance Status < 70 with no systemic therapy options do not derive benefit from radiation therapy. Additional information is available at www.asco.org/neurooncology-guidelines .